Skincare Ingredients Explained: The Science Behind What Goes Into a Formula

Every skincare product is a set of ingredients doing different jobs at the same time. Some carry the formula, some hold water at the skin surface, some soften, some cleanse, some keep oil and water mixed, some set the texture, and a small number are there for a specific appearance or feel benefit. A few protect the product itself. Reading a label well means asking which job each ingredient is likely doing, and accepting that the label alone cannot tell you how well it does it.

Start Here: What This Ingredient Guide Explains

This guide explains skincare ingredients by function. It is written for curious readers who want to understand what is in the products they use, and for people building a skincare brand who need a shared vocabulary before they talk to a developer.

You can read it in three ways. If you want to understand a label, start with the chapter on reading an ingredient list and then the functional map. If you want to compare product types, such as a gel against a lotion, read the chapters on water, humectants, emollients, emulsifiers and thickeners, then the three annotated walkthroughs. If you are preparing a product brief, the chapters on formula context and the final chapter connect ingredient knowledge to the questions a development partner will ask.

Each ingredient family is described the same way: what the material is, what it generally does in a cosmetic, which formula conditions change its behaviour, and where the evidence stops. That last part matters. A cosmetic ingredient can have good published research behind it and still perform differently in a particular product, and nothing here is a treatment recommendation, a dosage or a promise that a combination suits every person.

How to Read a Skincare Ingredient List

An ingredient list is a legal declaration with a specific purpose: to tell a buyer which substances are in the product. It is useful, but it was never designed to describe how the product was made or how much of each ingredient it contains.

INCI, common names and naming differences between markets

Most ingredient lists you see on skincare use names from the International Nomenclature of Cosmetic Ingredients, or INCI. These are standardised names, so the same material appears under the same name whichever supplier sold it. Glycerin, Niacinamide, Sodium Hyaluronate and Cetearyl Alcohol are all INCI names.

Naming is close but not identical across markets. In the European Union, the label must list all ingredients, and Ireland's regulator explains that the INCI name should be used for each one. The European Commission maintains CosIng, a database of ingredient names and functions, together with a glossary of common names for labelling.

The United States works from a different legal basis. FDA's guidance on cosmetic ingredient names says retail cosmetics must list ingredients by their "common or usual names". FDA does not accept "Aqua" or "Parfum" as substitutes for "Water" or "Fragrance", although it does not object to the alternative name in parentheses, as in "Water (Aqua)". That is why a product sold in both markets often shows dual names.

Two practical points follow. First, an unfamiliar name is not a warning sign by itself. "Butyrospermum Parkii Butter" is shea butter, and "Tocopherol" is a form of vitamin E. Second, CosIng is an information tool. The Commission states that CosIng "has informative purpose and no legal value", and that an INCI name appearing in its inventory does not mean the ingredient is approved for use. The legal status of an ingredient in the EU is set by Regulation (EC) No 1223/2009 and its annexes.

Order on the label, the lower-concentration area and what is not disclosed

Ingredients are generally listed in descending order of amount, but both major systems have exceptions.

Under US rules, FDA's Cosmetics Labeling Guide explains that ingredients present at 1% or less may be listed in any order after those above 1%, and colour additives may be listed in any order after the other ingredients. Fragrance and flavour may be declared simply as "Fragrance" or "Flavor". An ingredient FDA has accepted as a trade secret can be replaced with the phrase "and other ingredients". Certain incidental ingredients need not be declared at all. FDA's examples include a processing aid removed before packaging, and a preservative carried in with a raw material at a level where it no longer has an effect in the finished product.

EU labelling follows Article 19 of the Cosmetics Regulation, which has its own provisions on ingredient order and declaration. Fragrance allergens have a separate EU labelling rule, covered in the fragrance chapter. Anyone preparing an EU label should work from the current legal text rather than from US practice.

The practical lesson is that you cannot locate the 1% line from the label. A list may show water first, glycerin second and a fashionable active eighth, but nothing on the pack tells you whether that active sits at a meaningful level or in the "any order" zone. The label does not show percentages, and it was not meant to.

Raw-material blends, botanical names and why a label is not a recipe

Many raw materials that a formulator buys are themselves mixtures. A botanical extract may arrive dissolved in glycerin or butylene glycol and carry its own preservative. An emulsifier may be sold as a blend of two or three substances. On the finished label, each declared component appears separately in its position in the list, so a single purchased material can show up as three names scattered across the list, while two materials bought from different suppliers can collapse into the same INCI name.

Botanical names add another layer. Plant ingredients are usually declared with the Latin genus and species plus the plant part and type of preparation, such as "Camellia Sinensis Leaf Extract". The name tells you the source. It does not tell you the solvent, the extraction method, the concentration of the extract, or which constituents it contains.

Put these points together and the limits of a label become clear. An ingredient list does not give you percentages, raw-material grades, suppliers, the order of addition, temperatures, mixing methods or in-process checks. Two products with almost identical lists can feel, look and age differently. Our guide to cosmetic formulation explains why a manufacturing formula contains far more than a label. For a reader, the useful question is narrower: given this list, what kind of product is it, which ingredients are probably doing the main work, and what would I need to know that the label cannot tell me?

The Functional Map of a Skincare Formula

A formula is easier to understand as a set of jobs than as a list of names. The map below groups common skincare ingredients by the role they usually play. It is a reading aid, not a classification that every chemist would draw in exactly the same way.

Carriers, structure, sensory properties, benefit ingredients and protection

The map has five broad layers. The carrier is what the product mostly is: water in a gel, lotion or cleanser, or oils in a balm. Structure covers what makes the product hold its shape and stay mixed, which includes emulsifiers and thickeners. Sensory properties are the slip, cushion, finish, scent and colour that people notice first. Benefit ingredients are the ones a brand usually names on the front of the pack. Protection keeps the product itself in good condition through storage and use.

The ingredients a product is marketed on are usually a small share of the list. Most of the list exists to make those ingredients usable, stable and pleasant.

Why one ingredient can have several functions

Many materials do more than one job. Glycerin is a humectant and also changes how a product spreads and dries. Cetearyl Alcohol is a fatty alcohol that adds body to an emulsion, helps stabilise it and contributes to a soft feel. Butylene Glycol is a solvent and a humectant. Ethylhexylglycerin, often paired with preservatives, is listed in CosIng as a skin-conditioning and deodorant ingredient. Panthenol is usually discussed as a benefit ingredient, but dermatology reviews also describe it acting like a moisturiser.

CosIng lists more than one function for many ingredients for this reason. Its entry for Glycerin, checked for this guide, names humectant, solvent, skin protecting and viscosity controlling among others. When you see an ingredient in a list, the question is which of its possible jobs it is doing in this product, and the answer depends on the rest of the formula.

Ingredient identity, material grade and final formula are different

Three things are easy to confuse. The ingredient identity is the substance, described by an INCI name. The material grade is a specific commercial product a supplier sells, with its own purity, physical form, carrier and data sheet. The final formula is the full product that combines many grades in specific proportions using a specific process.

The same INCI name can cover very different grades. "Sodium Hyaluronate" covers materials with very different molecular weights. A botanical extract sold under one INCI name can differ between suppliers in solvent, plant part and processing. A supplier's data sheet describes its grade, tested in its own conditions, and does not describe every grade sold under that name. Neither the INCI name nor the grade tells you how the final product behaves. That gap between ingredient, grade and finished product runs through the whole guide.

Water, Solvents and Carriers

Water is the first ingredient in most creams, lotions, gels, toners and cleansers. Some readers take that as a sign of a cheap product. In practice, water is the medium most skincare formulas are built in, and it changes almost every other decision.

Water as a formulation medium rather than an empty filler

Water dissolves many skincare ingredients, including humectants, many vitamins and salts, most surfactants and many polymers. It lets a formula spread thinly and evenly. When it evaporates from the skin after application, it leaves behind the non-volatile ingredients as a film, and the feel of that film is a large part of how a product is judged.

Water also brings responsibilities. A water-containing product can support microbial growth, which is why water-based products need a preservation strategy. FDA lists contaminated raw materials and water among the ways microorganisms get into cosmetics. Manufacturers therefore treat water as a controlled raw material rather than an afterthought. Water also allows some ingredients to break down. A review of vitamin C delivery by Caritá and colleagues lists reducing water content among the strategies used to keep that ingredient stable, which is one reason some actives are offered in protected forms or in water-free products.

So "water first" tells you the product is water-based. It does not tell you the product is weak or diluted. A water-free product is not automatically more concentrated or more effective either. It is a different structure with its own constraints.

Water-soluble and oil-soluble materials

The most basic sorting question in a formula is whether a material dissolves in water, in oil, or in neither. Glycerin, niacinamide and panthenol are water-soluble. Plant oils, esters, retinol and tocopherol are oil-soluble. Many waxes dissolve in hot oil but not at room temperature.

This sorting decides where an ingredient goes. A water-soluble active belongs in the water phase of a lotion or in a gel. An oil-soluble active needs an oil phase, an emulsion or a solubilizer. When a product needs both kinds of ingredient, it needs a structure that holds both, which is the job of emulsifiers.

Other solvents sit between the two. Glycols such as butylene glycol and propanediol dissolve some ingredients that water alone handles poorly. CosIng lists butylene glycol as both a solvent and a humectant, and propanediol as a solvent and viscosity-controlling ingredient. Ethanol, declared as "Alcohol" or "Alcohol Denat.", dissolves some ingredients, evaporates quickly and changes the feel on skin. Each solvent changes how other ingredients behave, so a solvent choice is also a feel and stability choice.

Dissolving, dispersing and suspending are different processes

Three words are often used loosely. Dissolving means the material breaks up into individual molecules or ions in the solvent, as salt does in water, and the result is clear. Dispersing means the material is spread through the carrier as tiny droplets or particles that remain separate. Milk is a dispersion of fat droplets in water, and so is a lotion. Suspending means holding solid particles, such as pigments, exfoliating particles or encapsulated beads, evenly in the product so they do not sink or float.

These processes need different ingredients. A dissolved ingredient needs the right solvent and stays stable only within certain conditions. A dispersion needs an emulsifier or a dispersing agent. A suspension usually needs a thickener with enough structure at rest to stop particles moving, which is covered in the thickener chapter. A cloudy gel is not necessarily a failed gel, and a clear one does not prove every ingredient has fully dissolved. Appearance is a clue, not a measurement.

Humectants: How Water-Binding Ingredients Work

A humectant is an ingredient that attracts water and holds it. In skincare, humectants are the main reason a product leaves skin feeling hydrated right after use, and they appear in almost every water-based formula.

The skin already has its own humectants. The outer layer of skin, the stratum corneum, contains a mixture of small water-soluble compounds known as natural moisturizing factor. A review of skin barrier function by Rawlings and Harding describes how this mixture, together with the lipids between skin cells and the long, winding path water has to travel, helps the stratum corneum keep its water. Cosmetic humectants add to that water-holding capacity at the surface. DermNet, a dermatology reference, describes humectants as "hydrophilic" ingredients that attract and retain water in the stratum corneum, similar to natural moisturizing factor.

Glycerin, glycols and hyaluronic-acid materials as representative profiles

Glycerin (also spelled glycerol) is the most widely used humectant in skincare. It is a small molecule with three hydroxyl groups, which is why it binds water so readily. It is also one of the most studied. A review in the British Journal of Dermatology by Fluhr and colleagues summarises reported effects of glycerol on the stratum corneum, including improved hydration, barrier function and mechanical properties. The same review notes that the skin produces and transports its own glycerol. Glycerin's limits in a formula are mostly sensory. At higher levels it can feel sticky, and formulators balance it against other ingredients to control that.

Glycols such as butylene glycol and propylene glycol are small humectants that also act as solvents. They often appear near the top of a list because they help dissolve extracts or other ingredients, and some raw-material extracts arrive already dissolved in them. Formulators often use them alongside glycerin or in place of part of it to adjust feel, though every formula balances them differently.

Hyaluronic-acid materials are declared as Hyaluronic Acid, Sodium Hyaluronate, Hydrolyzed Hyaluronic Acid and several related names. Hyaluronan is a large sugar-based polymer found naturally in skin. In a cosmetic, it binds water and forms a thin film as the product dries. Its behaviour depends heavily on molecular weight, which the label does not show.

Other humectants include urea, sodium PCA, sugars and sugar alcohols such as sorbitol, and some amino acids. DermNet lists urea and alpha hydroxy acids among humectants and notes that they are also keratolytic, meaning they have a descaling effect, and that they often sting on scratched or fissured skin.

Water binding, tack, film and environment

Humectants pull water from wherever water is available. In a humid environment, that can include moisture from the air. In dry air, humectants mostly hold the water they arrive with and water drawn from the skin's own reserves. This is why a humectant-only product can feel excellent in a humid climate and less satisfying in a dry, cold room. It is also one reason many moisturisers pair humectants with emollients or occlusives, which slow down the water's escape. The next chapter covers those.

The other practical effect of humectants is feel. As water evaporates from a freshly applied product, the humectants concentrate on the skin. A high-glycerin product can leave a tacky layer. High-molecular-weight hyaluronic acid forms a smooth film that some people like and others describe as tight. Formulators adjust the type, combination and level of humectants to set how a product feels at application and a few minutes later. The ingredient list shows which humectants are present, but not how they have been balanced.

What molecular weight and a label alone cannot prove

Hyaluronic acid shows why an ingredient name alone does not describe performance. "Sodium Hyaluronate" can describe very long chains of over a million daltons or much shorter fragments. Large molecules mostly stay at the surface and form a film. A 2025 review in Biomolecules by Zanchetta and colleagues concluded from the literature that hyaluronic acid below 100 kDa penetrates skin, with lower molecular weights able to reach deeper layers. A separate 2025 review by Takagi and colleagues notes that, because of its size, most conventional hyaluronan "remains on the skin surface".

Clinical results also vary with molecular weight. In a 60-day study by Pavicic and colleagues, 76 women applied creams containing 0.1% hyaluronan of different molecular weights around one eye and a vehicle cream around the other. All of the hyaluronan creams improved measured hydration and elasticity compared with the vehicle. Only the two lowest-molecular-weight groups showed a significant reduction in measured wrinkle depth. That is one study in one product format, with one concentration and one population. It shows that molecular weight is a real variable. It does not show that any product with "low molecular weight hyaluronic acid" on the label will produce the same result.

Several things therefore cannot be read from a humectant's place on the list: its molecular weight, its grade, its exact level, how it has been balanced against other ingredients, and whether the finished product has been tested for the result a brand wants to claim. Topical hyaluronic acid is also a different subject from injected hyaluronic-acid fillers. Results from injected products say nothing about what a cream or serum does on the skin surface.

Emollients and Occlusives: Softness, Slip and Water-Loss Control

Emollients and occlusives are the oily, waxy and silicone-based ingredients in a formula. They are responsible for much of what people notice about a product's feel, from a dry, silky finish to a rich, cushiony one, and some of them also slow water loss from the skin.

Oils, esters, fatty alcohols, silicones and waxes by function

DermNet describes emollients as ingredients that "soften and smooth skin". In practice, they fill the small gaps between the flaking edges of surface skin cells and change how a product spreads. The term moisturiser is often used for the whole product, and a review by Lodén notes that moisturisers typically combine emollients with humectants. The main families are below.

CosIng records some of these materials with more than one function. It lists Caprylic/Capric Triglyceride as a solvent and occlusive skin-conditioning agent, and Cetearyl Alcohol as an emollient, emulsion stabiliser and viscosity-controlling ingredient. That fits the theme of the functional map: one material, several jobs.

Silicones need one market note. Under Commission Regulation (EU) 2024/1328, an amendment to the EU chemicals regulation REACH, the cyclic silicones known as D4, D5 and D6 may not be placed on the market in mixtures at 0.1% or more by weight once the restriction applies. For wash-off cosmetics, the D4 and D5 limit has applied since 31 January 2020. For other cosmetics, the restriction applies after 6 June 2027. D5 is the material declared as Cyclopentasiloxane. Linear silicones such as Dimethicone are not covered by that entry, but any silicone choice for a specific market should be checked against that market's current rules.

Emollient, occlusive and barrier-support roles compared

Three roles are often blurred together.

An emollient changes surface feel. It makes skin feel smoother and softer, and it decides how a product glides during application.

An occlusive forms a water-repelling layer that slows evaporation of water from the skin. DermNet lists petroleum jelly, paraffin, mineral oil and dimethicone as examples. Occlusion is a matter of degree. Petrolatum is at the strong end, many light esters at the weak end.

Barrier support is a broader idea that refers to the skin's own barrier, the organised lipids and cells of the stratum corneum. Some ingredients may support that structure more directly than simply covering it. The evidence for petrolatum is an interesting example. A 1992 study by Ghadially and colleagues found that petroleum jelly applied to deliberately disrupted human skin did not slow barrier recovery as a pure seal might be expected to. It moved into the spaces between the outer skin cells and barrier recovery proceeded normally. Ceramide-based systems, covered in the profile chapter, are a different approach to the same goal.

These roles overlap in real ingredients. Dimethicone is an emollient and, depending on the grade and level, an occlusive. Shea butter softens and adds some occlusion. The useful question when reading a list is what balance the product is likely aiming for. A light daily lotion and a rich night cream will both contain emollients, but in different types and amounts.

Lightweight and rich textures arise from the full formula

It is tempting to assume that an oil-free product is light and an oil-rich one is heavy. Texture is decided by the whole system. A product built on light esters and a volatile silicone can contain a fair amount of oil phase and still feel almost weightless, because the ingredients spread fast and some evaporate. A product with very little oil can feel heavy if it contains a high level of film-forming polymer or glycerin.

Texture also depends on what holds the oil phase, which is the emulsifier, and on how the water phase has been thickened. A supplier technical sheet for one emulsifier, discussed in the emulsifier chapter, says directly that lighter emulsions result from oils that spread better and have lower viscosity, and that the feel can also be adjusted through the amount of oil phase. That is one supplier describing its own material, but the principle is general: finish is designed through combinations, not through one ingredient.

There is also an individual side. The Lodén review notes that some formulations may improve the skin barrier while others may worsen it, and that greasy textures and strong odours reduce how willingly people use a product. A technically good emollient system that nobody wants to apply does little in practice.

Surfactants: Cleansing, Foam and Rinse-Off Feel

A surfactant is a molecule with a water-loving end and an oil-loving end. That dual nature lets surfactants sit at the boundary between oil and water and lower the tension there. Cleansers rely on surfactants to lift oil and dirt so they rinse away. Surfactants also appear in small amounts in many leave-on products, where they help wet surfaces, disperse ingredients or act as emulsifiers.

Anionic, amphoteric, nonionic and cationic functions

Surfactants are grouped by the electric charge on their water-loving end.

CosIng lists Sodium Laureth Sulfate under cleansing, foaming and emulsifying functions, and Cocamidopropyl Betaine under cleansing, foam-boosting and viscosity-controlling functions. Most facial cleansers combine at least two classes. A common pattern is a primary anionic surfactant with an amphoteric co-surfactant, sometimes with a nonionic, because the blend usually feels milder and foams better than the main surfactant alone.

Micelles and cleansing explained

Above a certain concentration in water, surfactant molecules group into tiny clusters called micelles. Each micelle has its oil-loving tails pointing inward and its water-loving heads facing outward. When a cleanser meets oily residue on skin, the oil-loving tails pick up the oil and hold it inside micelles, which rinse away with water. Micellar waters work on the same principle with a gentler, dilute surfactant system designed to be wiped off rather than rinsed.

The same property that lets surfactants remove sebum and makeup also lets them interact with the skin's own lipids and proteins. A review by Ananthapadmanabhan and colleagues explains that harsh surfactants can damage skin proteins and lipids, leading to tightness and dryness after washing. The review notes that interactions with proteins vary considerably with the surfactant's head group. It also reports that high-pH solutions, even without surfactants, increased swelling of the stratum corneum in the authors' studies. A 2018 review by Draelos contrasts alkaline soaps with synthetic detergents, often called syndets, which it describes as less barrier-damaging.

Skin's natural surface pH is acidic. A multicentre study by Lambers and colleagues of 330 people estimated the natural skin surface pH of the forearm at an average of about 4.7. Cleanser pH is one reason why two cleansers with similar surfactants can feel different afterwards.

For a facial-cleanser brief, review our cleanser manufacturing page and describe the foam, rinse-off feel and intended pack.

Foam, cleansing strength and mildness are not interchangeable

People often judge a cleanser by its foam. Foam is a separate property from cleansing power, and both are separate from mildness.

Foam depends on the surfactant type, the amount, the water hardness and foam boosters. Some very effective cleansing systems, including many cleansing oils and balms, barely foam at all. Some high-foaming systems can be mild if the surfactants are carefully combined.

Cleansing strength describes how much oil and residue the product removes. A cleanser for removing long-wear sunscreen and makeup needs more cleansing power than a morning cleanser for skin that only has a little overnight sebum.

Mildness describes how little the cleanser disturbs the skin's own lipids and proteins. It depends on the surfactant blend, the pH, the contact time and what else is in the formula. The Ananthapadmanabhan review notes that mildness enhancers and moisturising agents, such as lipids, occlusives and humectants, can reduce damaging interactions between surfactants and skin.

A label can tell you which surfactants are present. It cannot tell you the overall concentration, the pH, or how the finished product has been balanced. Calling a cleanser gentle is a product claim that needs product-level support, not an inference from one ingredient name.

Emulsifiers and Solubilizers: Keeping Different Phases Together

Oil and water do not mix on their own. Shake them together and they separate within minutes. Lotions, creams and many serums contain both, so they need ingredients that hold the two phases together for months or years. Those ingredients are emulsifiers.

O/W and W/O structures

An emulsion is one liquid spread through another as tiny droplets. In an oil-in-water (O/W) emulsion, oil droplets are dispersed in a continuous water phase. Most lotions and many creams are O/W. They usually feel lighter, rinse off more easily and spread as a water-based product does at first touch. In a water-in-oil (W/O) emulsion, water droplets are dispersed in a continuous oil phase. W/O products are often richer. A German dermatology position paper on dry skin advises that the drier the skin appears, the greater the lipid content of the care product should be, and names water-in-oil formulations as preferred for that purpose.

The structure type is a starting point, not a verdict. O/W does not automatically mean lightweight, and W/O does not automatically mean greasy. Oil choice, phase ratio and thickening all change the result.

Emulsifier, solubilizer and co-emulsifier roles

An emulsifier is a surfactant designed to sit at the oil-water boundary and stabilise droplets. Formulators often describe emulsifiers by their hydrophilic-lipophilic balance, or HLB, a number that indicates whether a material leans towards water or oil. Supplier sheets quote it as one guide among several when choosing an emulsifier.

A co-emulsifier or consistency agent works alongside the main emulsifier. Fatty alcohols and glyceryl stearate are common examples. They strengthen the interface, add body and help build the network that keeps a cream stable.

A solubilizer handles a different task: dissolving a small amount of oil-soluble material, such as a fragrance or an essential oil, into a clear water-based product. Ingredients such as PEG-40 Hydrogenated Castor Oil and polysorbates are often used this way. A clear toner with a light scent usually contains a solubilizer, even though it is not an emulsion.

Emulsifiers are not neutral. The Lodén review notes that emulsifiers may weaken the skin barrier, which is one reason emulsifier choice and level are part of how a product's tolerance is designed. That is a general observation from the literature, not a ranking of any specific emulsifier.

A named material example and why its range is not universal

One supplier example shows how much of an emulsifier's behaviour is specific to its grade. Evonik's product page for TEGO Care 450 MB, an O/W emulsifier with the INCI name Polyglyceryl-3 Methylglucose Distearate, states that it "forms stable emulsions from pH 4.5 up to 8.5". An Evonik technical information sheet for the same material, dated February 2021, lists an HLB of about 12 and notes that creams based on it may need additional consistency-giving substances, such as glyceryl stearate with stearic acid or cetyl/stearyl alcohol.

That information is useful for a formulator choosing between materials. It is not a rule for every emulsifier, and it does not show that a finished cream made with this material is stable. The sheet itself says the product's performance "should be verified by testing" by the customer. Supplier ranges can also change between sheet versions, and other emulsifiers have different pH windows, salt tolerance and texture effects. Naming this material here is an illustration of how supplier data works. It does not mean the products described in this guide use it, or that GZ Cosmetics Lab has validated it.

The reader's takeaway is simple. When an emulsion product says it is stable, gentle or light, that is a property of the whole formula in its pack, confirmed by stability and sensory work on that product. The emulsifier's data sheet is where that work starts.

Thickeners, Gels and Film Formers

Thickeners decide how a product behaves before, during and after it touches the skin: whether it pours, drips, holds a peak, pumps cleanly, glides or drags, and what it leaves behind. Formulators often call this group rheology modifiers, because rheology is the study of how materials flow.

Polymers, gums and fatty structuring materials

Three broad families appear on most skincare labels.

Synthetic polymers include Carbomer and related acrylate polymers such as Acrylates/C10-30 Alkyl Acrylate Crosspolymer. They can build clear gels at low levels. Many of them need to be neutralised with a base before they thicken fully. A 2022 study by Berardi and colleagues on two carbomer grades describes them neutralised with bases and forming transparent hydrogels in water, and shows that alcohol type and level change how the polymer behaves. That is one reason carbomer gels are sensitive to pH, salts and some actives.

Natural and modified natural gums include Xanthan Gum, Sclerotium Gum, Cellulose Gum and Hydroxyethylcellulose. They are widely used in gels, serums and to thicken the water phase of emulsions. CosIng lists Xanthan Gum under binding, gel-forming, emulsion-stabilising and viscosity-controlling functions. Gums can feel slightly slippery or stringy at higher levels, and they tend to tolerate salts and pH changes differently from carbomers.

Fatty structuring materials include Cetyl Alcohol, Cetearyl Alcohol, Glyceryl Stearate and waxes. In creams they form an ordered network with water and emulsifier that gives body. In water-free balms and sticks, waxes set the hardness.

Film formers overlap with all three. Some polymers leave a thin, continuous layer on the skin as the product dries. Depending on the material, that layer can feel smooth, tight, tacky or barely noticeable. CosIng lists film forming among the functions of Hydroxyethylcellulose and the acrylate crosspolymer named above.

Viscosity, yield behaviour, spread and residue

Thickness is several properties, not one. Viscosity is resistance to flow, usually measured at a set temperature and with specific instrument settings. Yield behaviour describes whether a product holds its shape until a certain force is applied, which matters for suspending particles and for a gel that stays on a fingertip without dripping. A 2021 study of carbomer gels by Kolman and colleagues reports that the gels it studied were strongly shear thinning, with behaviour typical of yield-stress gels. Shear thinning means the gel flows more easily when it is pushed, pumped or spread, then thickens again at rest.

Spread describes how far and how easily the product moves across the skin. Residue is what remains after the water evaporates. Two products with the same viscosity reading can differ completely in spread and residue, because those depend on which thickener is used and on the rest of the formula.

Viscosity also changes with temperature. A gel that feels right in an air-conditioned room may run in a hot bathroom, and a cream that pumps well in summer may stiffen in winter shipping.

Why clear gel, serum and cream are not one fixed recipe

Product names describe experiences, not formulas. A serum can be a water-based gel, a light emulsion or an oil blend. A gel cream can be a lightly thickened O/W emulsion or a gel with a small amount of emulsified oil. A clear gel needs ingredients that stay dissolved or solubilised, which limits the choice of oils and some actives. A rich cream may rely mostly on fatty structuring materials and need very little polymer.

So the same thickener does not work in every product, and the same product type can be built with very different thickeners. A label that lists Carbomer tells you that a carbomer-type polymer is probably building the gel. It does not tell you the grade, level, neutraliser or how the gel will behave in a pump. Our formulation guide covers the brand decisions involved when texture and packaging have to fit together.

Common Benefit Ingredients: Eight Evidence-Bounded Profiles

Benefit ingredients, often called actives in marketing, are the ones named on the front of a pack. This chapter profiles eight widely used families. Each profile follows the same pattern: what the ingredient is, what it is generally used for in cosmetics, which formula conditions matter, and where the evidence stops. Each ends with a question worth asking a developer.

These profiles are educational. They do not recommend a level, a routine or a combination for any individual. Ingredients that also appear in medicines are discussed only in their cosmetic context. Many studies cited here tested one specific formula in a specific group of people, and their results describe that formula, not every product containing the same ingredient. Under US law, a product's intended use, including the claims made for it, can make it a drug rather than a cosmetic. FDA's page Is It a Cosmetic, a Drug, or Both? gives "regenerate cells" as an example of a claim that can make a product a drug.

Niacinamide

Identity. Niacinamide is a form of vitamin B3. It is water-soluble and is declared as Niacinamide. CosIng lists its cosmetic function as smoothing.

Cosmetic role. Niacinamide is used in moisturisers, serums and toners to support the appearance of even tone, smoothness and barrier-related comfort. In a study of cultured skin cells and topical application by Tanno and colleagues, nicotinamide increased ceramide synthesis in cells, and topical application increased stratum corneum ceramides and reduced transepidermal water loss in dry skin. In a 12-week split-face study by Bissett and colleagues, 50 women applied a 5% niacinamide formula to half the face and the vehicle to the other half; the niacinamide side showed improvements in the appearance of fine lines, spots, redness and yellowing.

Formula context. It is relatively easy to formulate in water-based products, which is part of its popularity.

Evidence limits. The clinical study above tested one formula, one level and one population. The cell findings explain a plausible mechanism, but they are not product evidence.

Development question. What evidence supports the specific claim at the level and in the base we are using?

For a serum brief, browse our serum product directions and specify the target texture, intended claims and dispenser.

Panthenol

Identity. Panthenol, often called provitamin B5, is a water-soluble alcohol form of pantothenic acid. It is declared as Panthenol. CosIng lists skin and hair conditioning among its functions.

Cosmetic role. It is used for a comfortable, soothed skin feel and for hydration. A review by Ebner and colleagues states that topical dexpanthenol "acts like a moisturizer", improving stratum corneum hydration and reducing water loss.

Formula context. It mixes easily into water phases and suits gels, lotions and creams. The review notes good skin penetration when it is used in a suitable vehicle, and it names water-in-oil emulsions as one example.

Evidence limits. Much of the research reviewed concerns dexpanthenol in dermatology and wound care. Those findings cannot be turned into cosmetic claims about healing or treatment.

Development question. Which part of the evidence relates to cosmetic use at our intended level, and which part comes from medical settings?

Hyaluronic-acid materials

Identity. This family covers Hyaluronic Acid, Sodium Hyaluronate, Hydrolyzed Hyaluronic Acid and related forms. All are based on hyaluronan, a large natural polysaccharide.

Cosmetic role. Hydration and a smooth surface feel. The humectant chapter covers how they bind water and form films.

Formula context. Molecular weight changes behaviour. Large molecules mostly stay on the surface, while smaller fragments penetrate further, according to the 2025 Zanchetta review. Several molecular weights are often combined. High-molecular-weight grades also thicken water.

Evidence limits. The Pavicic study discussed earlier tested 0.1% creams with defined molecular weights. Its results do not transfer to a product that only says "multi-molecular-weight hyaluronic acid". Injected hyaluronic-acid filler data is irrelevant to topical claims.

Development question. Which grades and molecular weights are used, and what was tested in the finished product?

Ceramide systems

Identity. Ceramides are lipids that make up a large part of the material between the cells of the stratum corneum. Cosmetic ceramides include named forms such as Ceramide NP, Ceramide AP and Ceramide EOP, as well as ceramide-like substances sometimes called pseudo-ceramides. They are often supplied with cholesterol and fatty acids, which are also barrier lipids.

Cosmetic role. Ceramide-containing products are positioned to support the skin barrier and relieve dryness. A 2023 consensus paper by a panel of six dermatologists supports gentle, near-physiological-pH skin care containing ceramides for maintaining a healthy barrier.

Formula context. Ceramides are lipids that do not dissolve in water, so they need an oil phase, an emulsion or a specialised delivery system. Ceramide raw materials usually arrive as pre-made blends.

Evidence limits. A consensus statement is expert opinion built on earlier publications, not a controlled trial of a particular product. The ceramide level is not shown on the label.

Development question. Which ceramide system is used, how is it delivered, and what has been measured in the finished product?

For a cream or lotion brief, use our moisturizer manufacturing page to connect texture, packaging and formula-development requirements.

Vitamin C forms

Identity. "Vitamin C" covers several different materials. Ascorbic Acid is pure L-ascorbic acid. Derivatives include Sodium Ascorbyl Phosphate, Magnesium Ascorbyl Phosphate, Ascorbyl Glucoside, Ascorbyl Tetraisopalmitate and Ascorbyl Palmitate. CosIng lists Ascorbic Acid as antioxidant, buffering and skin conditioning, and Sodium Ascorbyl Phosphate as antioxidant.

Cosmetic role. Antioxidant support and the appearance of brighter, more even skin tone.

Formula context. Ascorbic acid is unstable in water. A study by Gallarate and colleagues found its degradation in water increased with rising pH and was slower in the emulsions it tested. A pig-skin study by Pinnell and colleagues reported that L-ascorbic acid had to be formulated below pH 3.5 to enter the skin in their model, and that three derivatives they tested did not raise skin levels of L-ascorbic acid. Derivatives were developed to improve stability. A 2022 review by Enescu and colleagues compares their efficacy.

Evidence limits. Results for one form do not transfer to another. A product label saying "vitamin C" does not identify which form is used or its stability.

Development question. Which form, at what pH, in what pack, and how was its stability checked?

Retinoid family

Identity. In cosmetics, this family mainly means Retinol, Retinyl Acetate, Retinyl Palmitate and, in some markets, Retinal (retinaldehyde). Tretinoin (retinoic acid) is a prescription medicine and is outside the scope of this guide.

Cosmetic role. Retinol is used for the appearance of smoother skin and fewer visible fine lines. A 2016 study by Kong and colleagues reported that topical retinol produced changes similar to retinoic acid in skin structure and gene expression, although smaller in magnitude, along with reduced facial wrinkles in its retinol clinical study.

Formula context. Retinoids degrade quickly with light, oxygen and heat, according to a 2024 review by Zhong and colleagues. Formulas usually rely on antioxidants, chelators, encapsulation and opaque or airless packaging. Irritation is a known issue. A 2006 review by Mukherjee and colleagues describes retinol and retinaldehyde as considerably less irritating than tretinoin.

Market rules. In the EU, Commission Regulation (EU) 2024/996, adopted in April 2024, restricts Retinol, Retinyl Acetate and Retinyl Palmitate to 0.3% retinol equivalent in leave-on and rinse-off products, or 0.05% in body lotion. It also requires the warning "Contains Vitamin A. Consider your daily intake before use". Under the regulation's transition terms, non-compliant products could not be placed on the EU market from 1 November 2025 and may not be made available from 1 May 2027. Later amendments and other markets' rules should be checked for the specific product.

Evidence limits. Treatment results for tretinoin cannot be applied to cosmetic retinol.

Development question. Which retinoid, at what level, for which markets, and how is it stabilised and packed?

Peptide materials

Identity. Cosmetic peptides are short chains of amino acids, often with a fatty-acid group attached to help delivery. Examples include Palmitoyl Pentapeptide-4, Palmitoyl Tripeptide-1, Acetyl Hexapeptide-8 and Copper Tripeptide-1. CosIng lists Palmitoyl Pentapeptide-4 as a skin-conditioning ingredient. A 2009 review by Gorouhi and Maibach groups peptides into signal, enzyme-inhibitor, neurotransmitter-inhibitor and carrier peptides.

Cosmetic role. Mostly the appearance of fine lines and firmness. In a 12-week split-face study reported by Robinson and colleagues, 93 women used a moisturiser with or without 3 ppm palmitoyl pentapeptide, and the peptide side showed significant improvement in wrinkles and fine lines.

Formula context. Peptides are usually supplied as dilute solutions in water or glycols, so the trade name level is not the peptide level.

Evidence limits. Evidence differs widely from one peptide to another, and the Gorouhi and Maibach review grouped peptides by mechanism because they are not one ingredient. Results for one peptide do not apply to the whole category.

Development question. Which specific peptide is used, at what actual peptide level, and what is the evidence for that one?

Botanical extracts

Identity. An extract is a complex mixture taken from a plant, declared by the Latin name, plant part and preparation, such as "Centella Asiatica Extract" or "Camellia Sinensis Leaf Extract". CosIng lists many functions for some extracts. Its entry for Camellia Sinensis Leaf Extract names eleven, including antioxidant, humectant and skin conditioning.

Cosmetic role. Extracts are used for soothing, antioxidant and skin-conditioning effects, and often for the product's story.

Formula context. Composition varies with growing conditions, plant part, extraction solvent and processing. Extracts often arrive in a carrier with its own preservative.

Evidence limits. A review by Mortimer and colleagues notes that essential oils are hard to standardise and can cause allergic contact dermatitis. A review by Jack and colleagues names Compositae-family plants, tea tree oil and lavender among botanicals implicated in cosmetic contact allergy. A study on one supplier's extract does not describe another supplier's extract with the same INCI name.

Development question. Which supplier's grade is used, what is it standardised to, and what data supports it in this product?

Protection and Support Ingredients

Every water-containing product needs a way to protect itself during storage and use. Several kinds of supporting ingredients each handle a different part of that job.

Microbial protection, in brief

Water-based products can support bacteria and fungi. FDA lists the main routes of contamination as raw materials or water, poor manufacturing conditions, ineffective preservation, packaging that doesn't adequately protect the product, poor shipping or storage, and consumer use such as dipping fingers into the product. Preservatives are one part of the answer. Manufacturing hygiene and packaging design are the others.

Common preservative ingredients on skincare labels include Phenoxyethanol, Sodium Benzoate, Potassium Sorbate, Benzyl Alcohol and parabens such as Methylparaben. Many are used in combination, sometimes with supporting ingredients such as Ethylhexylglycerin or Caprylyl Glycol. In the EU, a substance used as a preservative must be listed in Annex V of the Cosmetics Regulation and used within the conditions set there. In the US, the manufacturer is responsible for product safety.

A preservative's name on a label does not show that the product is adequately protected. That depends on the whole formula, its pack and how it is used, and it is confirmed by testing the finished product. Our separate guide to cosmetic preservatives explains preservation as a full system, and our article on preservative challenge testing covers how that testing is commissioned.

Antioxidants, chelators and pH adjusters have different jobs

Antioxidants slow oxidation, which can make oils go rancid, darken colours or degrade sensitive actives. Tocopherol is the most common example. CosIng lists it under antioxidant and skin-conditioning functions. Antioxidants protect the formula. They do not protect against microbes.

Chelators bind metal ions that can speed up oxidation and destabilise some ingredients. Disodium EDTA is common, and alternatives such as Sodium Phytate and Tetrasodium Glutamate Diacetate are also used. A 2023 study by Wang and colleagues on stabilising retinol formulas describes retinol degrading under light, oxygen and metal ions, and EDTA salts as metal-chelating stabilisers.

pH adjusters set and hold the product's pH. Citric Acid lowers pH, while Sodium Hydroxide or Arginine raises it. Their position near the end of a list says little about their importance, because a small amount can decide whether a thickener works or an active stays stable.

Fragrance, Colour and Sensory Ingredients

Not every ingredient is there for a skin benefit. Some exist because people use products more willingly when they look, smell and feel pleasant, and because some raw materials have their own odour or colour that needs covering.

Why sensory ingredients are used

Sensory ingredients include fragrance, colourants, cooling agents such as menthol derivatives, and texture modifiers such as silica or starch powders that give a dry finish. They help a product feel finished and consistent from batch to batch. Fragrance also covers the base smell of some raw materials. FDA notes that even some products labelled "unscented" may contain fragrance ingredients added to mask other odours without adding a noticeable scent.

Colour additives are regulated more strictly than most cosmetic ingredients in the US. FDA states that cosmetics and their ingredients do not need FDA approval before marketing, with the exception of colour additives other than coal-tar hair dyes. In the EU, colourants must be listed in Annex IV of the Cosmetics Regulation.

Fragrance compositions and allergens

A fragrance is usually a blend of many substances. Under US rules, it can be declared as "Fragrance". FDA notes that some fragrance components can cause allergic reactions in some people. FDA's page on the Modernization of Cosmetics Regulation Act of 2022 (MoCRA) lists fragrance allergen labelling among the requirements MoCRA directs FDA to establish by regulation. The statutory instruction and the detailed labelling rules that implement it are two separate steps, so anyone preparing a US label should check FDA's current requirements for the implementing rule.

The EU names specific fragrance allergens. FDA's own allergens page summarises the original EU list of 26 substances, such as Linalool, Limonene, Citral and Geraniol, and the additional substances added in 2023. Commission Regulation (EU) 2023/1545 introduced individual labelling of these allergens when their concentration exceeds 0.001% in leave-on products and 0.01% in rinse-off products. Its transition terms let non-compliant products be placed on the EU market until 31 July 2026 and made available until 31 July 2028.

Essential oils fall within the same framework. FDA notes that there is no regulatory definition of "essential oils", and that plant-derived ingredients are treated like those from any other source. Many essential oils contain the listed allergens.

FDA's allergens page states that there is no federal standard or definition for terms such as "fragrance-free" or "for sensitive skin" in the US. Our article on fragrance and perfume OEM and our guide to cosmetic labeling requirements by market go further into fragrance products and market rules.

Why Formula Context Changes Ingredient Performance

The profiles above keep returning to one point: an ingredient's behaviour depends on its surroundings. This chapter gathers the main reasons in one place.

pH, solubility, phase location, stability and packaging

pH controls the chemical form of many ingredients. Ascorbic acid behaves differently at pH 3 than at pH 6. Carbomer thickens only once neutralised. Some preservatives work better in acidic products. The surfactant chapter showed that cleanser pH can change how skin feels after washing.

Solubility and phase location decide where an ingredient sits. In an emulsion, a water-soluble active lives in the water phase and an oil-soluble one in the oil droplets. Moving an ingredient to a different phase, or into an encapsulated form, can change its stability and how it reaches the skin. The Gallarate study on ascorbic acid found that emulsions slowed its degradation compared with plain water, with the most protection when it sat in the inner water phase of a multiple emulsion.

Stability covers both chemistry and structure. Actives can oxidise or break down. Emulsions can separate. Gels can thin. Colours and odours can drift. Heat, light and oxygen speed up most of these changes.

Packaging is part of the formula's environment. A clear jar exposes a product to light and air every time it is opened. An opaque airless pump limits both. Packaging also determines how much contact the product has with fingers. A light- or oxygen-sensitive ingredient that performs well in one pack may not in another.

Raw-material concentration versus active concentration

Many raw materials are sold diluted. A peptide may be supplied as a solution containing only parts per million of the peptide itself. An extract may be mostly glycerin or glycol. A ceramide may arrive as a small part of a lipid blend. When a brand hears that a product contains "5% of" a material, the useful follow-up is whether that is 5% of the supplier's blend or 5% of the active substance. These are different numbers, and the label shows neither.

Ingredient evidence versus evidence for the finished cosmetic

There are three levels of evidence. Mechanistic evidence comes from cells, tissue models or chemistry and explains how something might work. Ingredient clinical evidence comes from studies of a formula containing the ingredient, often a supplier's or researcher's own test formula. Finished-product evidence comes from testing the actual product that will be sold.

Each level answers a different question. A cell study may support plausibility. A clinical study of a 5% formula supports claims about that formula. What a new product needs is evidence that fits that product and the specific claim made for it. Ingredient data and studies on similar formulas can be part of that evidence, but they do not transfer automatically. Whether extra studies on the finished product are needed depends on the claim, the formula and the market.

Three questions draw on different evidence.

Safety. FDA's fact sheet for small businesses says FDA does not require specific tests for individual products or ingredients. It describes safety substantiation that can rely on existing data for ingredients and for formulas "similar in composition", plus any additional tests that are appropriate given those data. It names supplier data, published studies and Cosmetic Ingredient Review assessments as examples of existing information.

Efficacy claims. In the EU, Regulation (EU) No 655/2013 sets common criteria for claims. Its annex requires claims to be supported by "adequate and verifiable evidence", requires studies to be relevant to the product and the benefit claimed, and asks for a level of evidence consistent with the type of claim. A claim that carries an ingredient's properties over to the finished product needs its own support, for example by showing that the ingredient is present at an effective concentration.

Stability and packaging. Whether the product keeps its colour, odour, texture and active content in its actual pack is a separate question. Data on one ingredient, or on the formula in another pack, does not answer it.

An ingredient's research history is a reason to consider it, not proof of what a new product will do. Brands developing a product should agree the evidence plan for each intended claim at the brief stage. Our ODM development service describes how a project brief is set up. Our guide to cosmetic safety testing covers how evidence is assembled for launch, and our guide to stability testing reports explains what to look for in stability data.

Three Annotated Product Walkthroughs

The three lists below are fictional and written for teaching. They are not real products, customer formulas or GZ Cosmetics Lab products, and they do not show any concentration or manufacturing recipe. Each is read by function to show what a label can and cannot tell you.

Walkthrough 1: an illustrative hydrating gel

Fictional ingredient list: Water (Aqua), Glycerin, Butylene Glycol, Niacinamide, Sodium Hyaluronate, Panthenol, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Sodium Hydroxide, Allantoin, Phenoxyethanol, Ethylhexylglycerin, Disodium EDTA.

What can be inferred. This is a water-based gel without an emulsified oil phase, because no oils or emulsifiers appear. The thickener needs neutralising, so pH has been adjusted to build the gel. Humectants sit high on the list, so the product will probably feel hydrating. A tacky finish is possible, depending on how the glycerin level has been balanced.

What remains unknown. The niacinamide level, the hyaluronate molecular weight, the final pH, whether the product is fully clear, and how it feels after drying are all unknown. So are the preservation testing results and any data supporting a hydration claim.

Walkthrough 2: an illustrative daily lotion

Fictional ingredient list: Water (Aqua), Caprylic/Capric Triglyceride, Glycerin, Squalane, Cetearyl Alcohol, Polyglyceryl-3 Methylglucose Distearate, Glyceryl Stearate, Dimethicone, Ceramide NP, Cholesterol, Tocopherol, Xanthan Gum, Phenoxyethanol, Citric Acid, Sodium Phytate.

What can be inferred. The list is consistent with the oil-in-water emulsion this example was designed to represent: water leads, oils follow, and an O/W emulsifier with fatty co-emulsifiers is present. Water appearing first does not, on its own, establish which phase is continuous. Light esters and squalane suggest a moderate rather than heavy texture. A ceramide with cholesterol suggests a barrier-support positioning.

What remains unknown. The oil-phase proportion, the ceramide amount, whether ceramides are dissolved or delivered in a special system, the viscosity and its behaviour in a pump, and whether any barrier claim has been tested are all unknown. The emulsifier in this fictional list was chosen only because a supplier sheet is discussed in the emulsifier chapter. Its working range does not prove this list would be stable.

Walkthrough 3: an illustrative rinse-off cleanser

Fictional ingredient list: Water (Aqua), Sodium Laureth Sulfate, Cocamidopropyl Betaine, Glycerin, Decyl Glucoside, Sodium Chloride, Panthenol, Centella Asiatica Extract, Citric Acid, Sodium Benzoate, Fragrance (Parfum), Limonene, Linalool.

What can be inferred. This is a foaming gel cleanser built on a mixed surfactant system rather than a single surfactant. Salt is probably thickening it, a common approach for this kind of system. The individual declaration of limonene and linalool is consistent with EU-style allergen labelling. Citric acid shows that pH has been adjusted, but the label does not say to what value.

What remains unknown. The total surfactant level, the final pH, how mild it is in use, the extract's grade, and how much benefit the extract can give in a product rinsed off within a minute are all unknown. The presence of glycerin and panthenol does not prove the cleanser is gentle. Mildness is a finished-product property.

What the three walkthroughs show

Across all three products, the label reveals the product type, the likely structure and the main functional groups. It does not reveal quantities, grades, pH, process or test results. Reading by function lets you ask better questions. It does not let you judge performance from the list alone.

Common Ingredient Myths and Reader Questions

Natural versus synthetic

An ingredient's origin does not decide its safety. FDA's page on organic cosmetics says "an ingredient's source does not determine its safety", and notes that many plants contain toxic or allergenic substances. Many synthetic ingredients are well characterised, and many natural ones vary from lot to lot. Each ingredient needs to be judged on its own data and use.

"All alcohols are drying"

FDA's page on alcohol-free cosmetics explains that "alcohol" on its own in cosmetic labelling refers to ethyl alcohol. A product labelled alcohol-free may still contain fatty alcohols such as cetyl, stearyl or cetearyl alcohol, which FDA says have quite different effects on the skin from ethyl alcohol. Denatured ethanol can appear as "Alcohol Denat." or "SD Alcohol" with a number.

Higher concentration, short lists and fashionable actives

A higher level is not automatically better. More of an active can raise irritation or instability, and some ingredients have legal maximum levels in some markets, as the retinol profile shows. A short ingredient list is not automatically gentler: one ingredient can be an allergen for someone, and a short list may lack the support ingredients that keep a formula stable. A fashionable active has the same limits as any other ingredient. Its evidence belongs to its specific grade, level and formula. Our article on skincare active ingredient trends covers newer actives in more detail.

"Sulfate-free", "silicone-free" and "chemical-free"

"Sulfate-free" tells you a product avoids sulfate surfactants. It does not show that the product is milder, because mildness depends on the whole system. "Silicone-free" tells you silicones are absent, and the product may use other emollients for slip. "Chemical-free" is not meaningful, because water and every plant extract are chemicals. "Hypoallergenic" has no federal definition in the US, according to FDA's page on hypoallergenic cosmetics, which says the term "means whatever a particular company wants it to mean".

"Can I tell from the label if a product will suit me?"

The label can help you avoid an ingredient you already know you react to. It cannot predict how your skin will respond to a new product. FDA advises people concerned about allergies to read ingredient panels carefully and follow the manufacturer's directions. Anyone with a skin condition should seek advice from a qualified professional.

From Ingredient Knowledge to a Useful Product Brief

Ingredient knowledge is most useful when it shapes a brief. Our cosmetic formulation ingredients guide connects these ingredient roles to pH, texture, protection and the review a brand should complete before sampling. Before contacting a developer, it helps to write down:

• the product type and structure you have in mind, such as gel, lotion, cream or cleanser
• the feel you want at application and after a few minutes
• ingredients you want and want to avoid, with your reasons
• the claims you hope to make and the markets you plan to sell in
• the pack type, because pack and formula affect each other
• any reference products, treated as direction and not as a recipe

You can browse existing directions in our skincare product range, including serums, essence lotions and facial cleansers. If you need a formula developed around your brief, our ODM development service explains how projects begin. When your brief is ready, you can request a quote and include your reference products and intended markets.