INCI: A complete guide to reading and understanding ingredients

I. What is INCI and how to interpret it

There's a list on every cosmetic product that most people ignore. It's in small print, in Latin or technical English, and it's often squashed between the barcode and the recycling symbol. It's called INCI: International Nomenclature of Cosmetic Ingredients, and it's the only part of the packaging that can't lie to you.

Everything else is marketing. INCI isn't.

What it is exactly

INCI is the official and standardized list of ingredients for any cosmetic sold in Europe. It is regulated by the European Union and is mandatory for all products. The names follow an international nomenclature, mostly in Latin for botanical ingredients and English for chemical ones, so they are recognizable in any country, regardless of the label's language.

In other words: the INCI of a product bought in Spain, France, or Germany uses exactly the same names. It is the universal language of cosmetics.

The most important rule: the order

Ingredients are listed in descending order of concentration. The first on the list is the most abundant in the formula; the last, the least.

There's a nuance: from approximately 1% concentration, the order may no longer be strict. Ingredients in very small quantities—preservatives, fragrances, low-dose active ingredients—can appear in any order above that threshold.

In practice, this means two things:

What appears at the beginning matters. If the second ingredient is water and the third is alcohol, that tells you something. If the second is argan oil, that also tells you something.

Active ingredients at the end of the list are not necessarily useless. Some ingredients are very effective at low concentrations, such as niacinamide, retinol, or bakuchiol. Being at the end doesn't mean they do nothing; it means they are present in small quantities, which might be exactly what's needed.

INCI names vs. common names

The same ingredient can have an INCI name that looks nothing like what you know. Some examples from our catalog:

With a little practice, you'll recognize the common ones without thinking. And when you come across one you don't know, you know where to look: in our Learn More section or the general glossary, where we break them down one by one. There are also apps like INCI Beauty, or Yuka which is incorporating cosmetics into its database.

Asterisks and what they mean

In many INCIs, you'll see ingredients with one or more asterisks. There isn't a single standard; each brand uses them in its own way, but the most common meanings are:

Organic farming asterisk. Indicates that the ingredient comes from certified organic farming. Some manufacturers state the total percentage of organic ingredients at the bottom of the INCI list.

Natural origin asterisk. Similar to the above but broader, it indicates natural origin without necessarily implying organic certification.

Fragrance allergens. Certain components of fragrances and essential oils: limonene, linalool, citral, geraniol, among others. These must be declared in the INCI if they exceed certain concentration limits. This doesn't mean the product is bad or will irritate you; it means it contains fragrance components that can sensitize some very reactive skin types. If you have very sensitive skin, this is information worth knowing.

What INCI doesn't tell you

INCI is a powerful tool, but it has limitations. It does not indicate:

Exact concentrations. With regulated exceptions, manufacturers are not required to declare the percentage of each ingredient. You know the order, not the quantity.

The quality of the ingredients. A virgin cold-pressed argan oil and a refined argan oil appear the same on the INCI list. The difference lies in the process, not the name.

The product's actual efficacy. An INCI list full of interesting active ingredients does not guarantee they will work if they are in insignificant concentrations or if the formula is not well-constructed.

That's why reading the INCI is the starting point, not the final verdict. It helps you eliminate what you clearly don't want and better understand what's inside, but it doesn't replace judgment or the experience of using the product.

Where to start

If you've never read an INCI, a good exercise is to take any product you have at home and ask yourself three questions:

What is the first ingredient? In most creams and moisturizers, it will be Aqua, water. Normal, it's the base. In an oil, it will be the main oil.

Do I recognize any active ingredients in the first five ingredients? If hyaluronic acid, niacinamide, or vitamin C appear among the first, they are present in significant amounts. If they appear at the end, they are in trace amounts.

Is there anything I don't recognize and that makes me doubt? Write it down and look it up. Most intimidating-looking ingredients are completely harmless. A long Latin name is not synonymous with aggressive chemicals.

II. Ingredient Groups and Their Functions

Let's go a step further: understanding what function each ingredient fulfills based on its category. Because knowing how to read a list is useful, but knowing what each thing does is what allows for truly informed choices.

Cosmetic ingredients are grouped by function. These are not rigid categories; the same ingredient can fulfill several functions at once, but knowing them allows for quick orientation when looking at any INCI.

Below, we review the main groups with some representative examples of each. A practical guide to identify them, know what to look for, and what you will commonly find on the label.

Humectants: attract water to the skin

Humectants are ingredients that capture water from the environment or from deeper layers of the skin and retain it in the superficial layers. Their effect is immediate and visible: the skin becomes hydrated, looking smoother and plumper.

The best known is hyaluronic acid, capable of retaining up to a thousand times its weight in water. Glycerin, present in almost any cream or serum, is the most commonly used humectant in cosmetics due to its effectiveness and low cost. Betaine, obtained from beets or coconut, hydrates with a very gentle and well-tolerated profile. Beta-glucan acts similarly but with a significant calming bonus for reactive skin.

In the INCI, you'll recognize them as: Sodium Hyaluronate, Glycerin, Betaine, Beta-Glucan.

Emollients: soften and make skin supple

Emollients fill the spaces between skin cells, smoothing the surface and improving flexibility and feel. They are responsible for that silky skin sensation after applying a product.

Vegetable oils are emollients par excellence: argan, jojoba, avocado, baobab, coconut. Each with a distinct fatty acid profile and different affinity depending on skin type. Squalane is another highly valued emollient for its ultralight texture and compatibility with all skin types, including oily skin.

In conventional cosmetics, silicones often fulfill this role: Dimethicone, Cyclopentasiloxane, Cyclohexasiloxane. They provide a very pleasant immediate sensation but form an impermeable layer on the skin without providing real nourishment.

In the INCI, vegetable oils appear with their botanical Latin name: Argania Spinosa Kernel Oil, Simmondsia Chinensis Seed Oil, Persea Gratissima Oil.

Occlusives: seal and protect the barrier

Occlusives form a protective film over the skin that slows down water loss through evaporation. They are always applied over humectants and emollients, sealing everything applied underneath. They are especially useful for very dry skin, in cold climates, or as part of a nightly routine.

Shea butter is the most versatile natural occlusive: it nourishes, protects, and soothes simultaneously. Vegetable waxes like candelilla wax or carnauba wax perform a similar function and frequently appear in lip balms and solid products.

In conventional cosmetics, the quintessential occlusive is petroleum jelly (Petrolatum), derived from petroleum: very effective at sealing but without any nourishing contribution. Lanolin (Lanolin), of animal origin, was also widely used before the expansion of plant-based alternatives.

Surfactants: cleanse and emulsify

Surfactants are ingredients with a molecular structure that allows them to act between water and oil, capturing dirt and sebum so that water washes them away when rinsed. They are the basis of any cleansing product.

But not all surfactants are the same. Sulfates, such as Sodium Lauryl Sulfate (SLS) or Sodium Laureth Sulfate (SLES), cleanse effectively but are aggressive: they excessively remove natural lipids from the skin and scalp, alter pH, and can cause irritation. They are responsible for the tight feeling after washing.

Coconut-derived surfactants are the most common alternative in natural cosmetics: Sodium Cocoyl Isethionate (SCI), Coco-Glucoside, Sodium Cocoamphoacetate. They cleanse while respecting the skin barrier, with adjusted pH and without drying it out. They are the basis of syndets and sulfate-free shampoos.

Surfactants also act as emulsifiers: they allow water and oils to coexist in a cream without separating. Without them, lotions and creams as we know them would not exist.

Active Ingredients: specific cosmetic function ingredients

Active ingredients are ingredients with a specific biological action on the skin: they stimulate, renew, brighten, or strengthen. They justify most of a product's marketing claims, and their efficacy also varies greatly depending on their concentration and the quality of the formula.

Some of the most relevant and well-documented include:

Antioxidants

They protect the skin from oxidative damage caused by pollution, sun, and stress. Vitamin C, astaxanthin, green tea, and pomegranate are examples with a solid scientific basis.

Cell renovators

They stimulate skin renewal, improve texture, and reduce wrinkles. Bakuchiol and phytoretinol are plant-based alternatives to retinol, with much better tolerability profiles. PHAs and succinic acid gently and controllably renew the skin's surface.

Regulators and uniformizers

They act on sebum, tone and the skin barrier. Niacinamide is the most versatile of all: it regulates, evens out, strengthens and soothes. Combined with N-Acetyl Glucosamine, they complement its action on blemishes and uneven tone. Our niacinamide serum is an example of this synergy between effective active ingredients that enhance their effects in a minimalist and carefully crafted formula.

Tightening and firming

They improve firmness and density. Kigelia africana has recognized tightening properties. Aloe vera soothes, hydrates and helps maintain elasticity.

Preservatives: necessary, but not all are the same

Any cosmetic product containing water needs preservatives. Without them, the product would be contaminated with bacteria and fungi in days. Preservatives are not the enemy; they are a technical necessity.

The problem is not their presence, but which ones are used. Parabens (Methylparaben, Propylparaben, Butylparaben) were the industry standard for decades. They are effective and stable, but their association with hormone disruption has put them in the spotlight, especially in high concentrations or with continuous use. Many brands have removed them, although the scientific debate is still open.

Phenoxyethanol (Phenoxyethanol) is the most common substitute in conventional cosmetics and also in many natural products. In correct concentrations, it is safe, but in excess, it can irritate very sensitive skin.

In well-formulated natural cosmetics, preservatives such as benzoic acid (Benzoic Acid), potassium sorbate (Potassium Sorbate), or alcohol (Alcohol Denat.) are used in functional concentrations. Solid products, as they do not contain free water, need much less or none, which is another real advantage of solid formats beyond the packaging.

Fragrances and allergens: what's behind "Parfum"

The word Parfum or Fragrance in an INCI list is one of the most opaque terms. It can hide dozens of different ingredients under a single name, because fragrance formulas are protected as trade secrets.

Within that fragrance can be components that generate reactions in some skin types: fragrance allergens. European regulations require the declaration of the most common ones when they exceed certain concentrations: Limonene, Linalool, Citral, Geraniol, Eugenol, Cinnamal, among others. Some come from natural essential oils, others are synthetic. Their presence does not mean that the product is bad, but it is relevant information for those with reactive skin or a history of allergies.

In conventional cosmetics, artificial fragrances are especially common and complex in composition. In cleaner formulations, individually declared essential oils are used, which allows the consumer to know exactly what they are exposed to.

A product with no fragrance of any kind will appear in the INCI without any mention of Parfum, Fragrance or essential oils. It is the safest option for very sensitive or reactive skin.

Colorants: when color adds nothing

Cosmetic colorants have no function on the skin. They are there to make the product visually attractive, nothing more. In the INCI, they appear with CI codes followed by a number: CI 77491 (red iron oxide), CI 42090 (blue), CI 19140 (tartrazine yellow).

Some synthetic colorants have generated controversy due to their potential irritant or allergenic properties. In natural cosmetics, mineral or plant-based pigments are used, but in any case, these are dispensable ingredients from a functional point of view. Their presence in an INCI is not a cause for alarm, but their absence is not a loss either.

What is not in the INCI

It is worth remembering, as we already pointed out in Part I, that INCI has its limits. It does not indicate exact concentrations, does not distinguish between a cold-pressed virgin oil and a refined one, and does not guarantee the actual effectiveness of a product. It is a transparency tool, not a quality certificate.

Reading the INCI with discernment, knowing the ingredient categories, and having access to reliable information about each one is what makes the back label list truly useful. That is also what our glossary of ingredients or the Learn More fact sheets are for.

III. Ingredient Nomenclatures and Patterns

This third part goes a step further: recognizing ingredients by name, without having to look them up one by one. There are patterns in the INCI nomenclature that, once known, allow you to identify what type of ingredient it is just by reading its name.

It's not foolproof; there are exceptions, but it covers the vast majority of what you'll find on a label.

Aqua: always water, always at the beginning

It is not abundant in our catalog, but it is in conventional cosmetics, especially because it is the basis of liquid formats. It is the simplest of all. Aqua is water, and in most creams, aqueous serums, and cleansing products, it usually appears as the first ingredient because it is the basis of the formula. There is nothing more to know about this, except that its presence implies that the product needs preservatives to avoid contamination.

If a product does not have Aqua in the INCI, it is anhydrous (water-free): oils, butters, solid bars, balms. These need much less or no preservative.

Oil, Butter, Wax: vegetable fats

Any ingredient ending in Oil is an oil. Seed Oil refers to oil extracted from the soft seed of the fruit. Kernel Oil is oil from the soft seed that is protected by a pit or very hard shell:

• Simmondsia Chinensis Seed Oil: jojoba seed oil.
• Rosa Moschata Seed Oil: rosehip seed oil.
• Argania Spinosa Kernel Oil: argan kernel oil.

If the name is more generic or chemical, it may be a mineral or synthetic oil: Mineral Oil, Paraffinum Liquidum (liquid paraffin). You will not find these in our catalog.

Butter indicates butter, and in natural cosmetics, it is always of plant origin:

• Butyrospermum Parkii Butter: shea butter.
• Theobroma Cacao Seed Butter: cocoa seed butter.

Wax or Cera are waxes. They function as occlusives and texturizing agents in bars and balms. All are of plant origin, except beeswax, which comes from beekeeping.

The INCI mixes Latin and English depending on the registration period: older names remained in Latin (Cera), newer ones are written in English (Wax). Same ingredient, different convention.

• Cera Alba: beeswax.
• Candelilla Cera: candelilla wax.
• Carnauba Wax: carnauba wax.

Botanical names in Latin: certified plant origin

Some botanical names you'll recognize right away: Lavandula Angustifolia is lavender, Rosa Damascena is Damask rose, Olea Europaea is olive. Others require a bit more practice, but the logic and pattern are always the same: genus + species + plant part + extract form.

• Camellia Sinensis Leaf Extract: green tea leaf extract.
• Punica Granatum Fruit Extract: pomegranate fruit extract.
• Aloe Barbadensis Leaf Juice: aloe vera leaf juice.

When you see two Latin words followed by Extract, Oil, Powder, Juice, or similar, you are looking at an ingredient of plant origin. It is one of the easiest INCI readings once you know the pattern.

The -ol: the suffix that can confuse

The suffix -ol indicates an alcohol, but here there is an important distinction worth knowing.

Fatty alcohols: long chain, solid at room temperature, emollients and stabilizers. They do not dry or irritate; on the contrary, they soften. Cetyl Alcohol, Cetearyl Alcohol, Behenyl Alcohol, Stearyl Alcohol. They are very common in creams and conditioners to give a creamy texture. Their name may sound like "alcohol" and cause alarm, but their behavior is completely different from volatile alcohol.

Volatile alcohol: Alcohol Denat., Ethanol, Isopropyl Alcohol. These evaporate quickly, can dry out and alter the skin barrier, especially on sensitive skin. In low concentrations and in well-constructed formulas, they are not necessarily problematic, but it is worth considering them if they appear among the first ingredients.

Active ingredients with -ol: some active ingredients also end in -ol due to their chemical structure: Retinol (vitamin A), Panthenol (provitamin B5), Tocopherol (vitamin E), Bisabolol (chamomile soothing agent). They have nothing to do with the previous alcohols, even if they share the ending.

The -ate and -ite: salts, esters, and preservatives

The suffix -ate indicates a salt or an ester. It is a very broad group that includes ingredients with very different functions.

Preservatives: Sodium Benzoate, Potassium Sorbate, Sodium Dehydroacetate. These are among the most commonly used preservatives in natural cosmetics, generally well tolerated.

Emulsifiers and stabilizers: Glyceryl Stearate, Cetearyl Glucoside (emulsifier derived from coconut), Sorbitan Olivate (emulsifier and surfactant derived from olive oil and sorbitol). Natural ones like these allow water and oil to coexist in a cream without separating, are biocompatible with the skin, retain moisture, and strengthen the natural lipid barrier.

Esters of vegetable oils: Esters are chemical compounds that form when an acid combines with an alcohol and loses a water molecule. In the world of cosmetics and nature, they are the components responsible for giving a good smell, softness, and texture to a wide variety of products. Caprylic/Capric Triglyceride (light fraction of coconut oil, very emollient), Isopropyl Myristate (synthetic emollient common in conventional cosmetics).

The suffix -ite follows the same logic but derives from different acids: where -ate comes from acids ending in -ic, -ite comes from acids ending in -ous. In cosmetic practice, the distinction does not change anything functional: Sodium Sulfite, Magnesium Ascorbyl Phosphite. Same reading criterion, different chemical family.

The -sulfate and -sulfonate: surfactants, but not all are the same

As we saw in Part II, surfactants are the basis of cleansing products. Those with -sulfate in their name are the best known, but not all have the same profile.

The aggressive ones: Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are the most common in mass-market products: shampoos, shower gels, conventional toothpastes. They clean effectively but excessively strip natural lipids, alter pH, and can irritate with continuous use. If they appear among the first ingredients of a cleansing product, the formula is aggressive.

The mild ones: not all names with sulf- are problematic. Sodium Lauryl Sulfoacetate (SLSA) is considerably milder than SLS despite the similar name. Disodium Lauryl Sulfosuccinate also has a much more respectful profile and is common in products for sensitive skin or children.

Coconut derivatives: Sodium Cocoyl Isethionate (SCI), the base of many syndets, is technically a sulfonic ester rather than a sulfate, but it is mentioned here because its name can cause confusion. Its behavior is completely different: mild, pH-balanced, non-drying. Coconut surfactants in general, Coco-Glucoside, Sodium Cocoamphoacetate, are the natural and respectful alternative to conventional sulfates.

The practical rule: SLS and SLES are the ones worth specifically avoiding. The rest require more context.

The -siloxane and -cone: silicones

Easy to identify. Any ingredient ending in -cone, -conol, -siloxane, or -silane is a silicone (Dimethicone, Cyclopentasiloxane, Cyclohexasiloxane, Phenyl Trimethicone).

Silicones are very effective emollients in functional terms: they give an immediate silky texture, soften, and add shine. The problem is that they form an impermeable occlusive film on the skin or hair without providing real nourishment. They create a "makeup effect" that conceals dehydration, and insoluble varieties (like Dimethicone) require harsh cleansers to remove. Due to their high environmental impact, many of them (such as cyclic or volatile ones) are under strict prohibitions in the European Union as they are not biodegradable.

In natural cosmetics, they are absent, replaced by vegetable oils and waxes that provide a similar effect with real benefits for the skin.

The -paraben: preservatives under scrutiny

The suffix -paraben makes them immediately recognizable: Methylparaben, Ethylparaben, Propylparaben, Butylparaben, Isobutylparaben.

They were the standard for preservation in cosmetics for decades due to their efficacy and stability. Their controversy arose from studies that detected parabens in breast tissue and their weak estrogenic activity, which placed them in the debate about endocrine disruptors.

The scientific evidence is still debated. The SCCS (Scientific Committee on Consumer Safety of the European Union) considers short-chain parabens (Methyl- and Ethyl-) safe at usual concentrations. However, authorities completely banned varieties like Isobutylparaben and strictly restricted Butylparaben and Propylparaben.

Many brands have preemptively withdrawn them. Their presence in an INCI is not automatically illegal, but it is relevant information for those who wish to avoid them.

CI + number: colorants, natural and synthetic

The prefix CI (Color Index) followed by a five-digit number identifies a colorant approved for cosmetic use. The system does not distinguish origin: under this prefix coexist mineral pigments, natural colorants, and synthetic ones derived from petroleum.

• Mineral pigments: CI 77491, CI 77492, CI 77499 are iron oxides that provide reddish, yellow, and black tones in natural cosmetics. CI 77891 is titanium dioxide (used for white color and as a sunscreen filter, although today it is highly monitored and restricted in powdered products). CI 77007 is ultramarine blue. All are of mineral origin and common in natural cosmetics.
• Of animal origin: CI 75470 is carmine, obtained from cochineal. It is a natural colorant but not vegan, a key fact for those seeking animal cruelty-free cosmetics.
• Synthetics: CI 42090 (blue), CI 19140 (tartrazine yellow), or CI 16035 (red). They are petroleum derivatives and are the most questioned for their potential allergenicity in sensitive skin.

Seeing the CI acronym in an INCI does not automatically imply a synthetic ingredient. To know, one must know the specific number or search to find out what it is. In any case, colorants have no function on the skin: they are there for aesthetic reasons of the product, not for the benefit of the user.

Fragrance allergens: those that must be declared

Within the term Parfum or Fragrance, there can be dozens of different compounds. European regulations require individual declaration of fragrance allergens when they exceed certain concentrations: 0.001% in rinse-off products and 0.01% in leave-on products.

The most common ones you'll see declared: Limonene (citrus), Linalool (lavender, other florals), Citral (lemon, lemon verbena), Geraniol (rose, geranium), Eugenol (clove, cinnamon), Cinnamal (cinnamon), Benzyl Alcohol, Coumarin, Citronellol.

Some come from natural essential oils, others are synthetic. Their presence doesn't mean the product is bad or poorly formulated: it means it contains fragrance compounds that can sensitize very reactive skin or skin with a history of allergies. For those with sensitive skin, reviewing this part of the INCI is especially useful.

A completely fragrance-free product will not have any of these terms or the word Parfum. It is the safest option for reactive skin.

For most people, however, sensory experience has some weight in their personal care routines. If you don't have reactive skin or a history of allergies, there's no reason to avoid them.

Actives: heterogeneous by nature

Actives are the most diverse group in nomenclature because they come from very different origins and do not follow a single pattern. However, there are recognizable subgroups.

Proper name of the compound in English: They are recognized because they are the direct name of the compound without systematic suffixes. With some practice, we will easily recognize them. Some examples:

• Niacinamide, Retinol, Caffeine, Bakuchiol, Astaxanthin.

Acids: many exfoliating, renewing or moisturizing actives have Acid in their name. Easy to identify. Examples:

• Lactic Acid (lactic acid), Hyaluronic Acid (hyaluronic acid), Ascorbic Acid (vitamin C), Glycolic Acid (glycolic acid), Azelaic Acid (azelaic acid).

Vitamins by their chemical name: they do not appear as "vitamin X" but by their technical name:

• Tocopherol or Tocopheryl Acetate is vitamin E. Ascorbic Acid is vitamin C. Niacinamide is vitamin B3. Retinol is vitamin A. Panthenol is provitamin B5.

Active botanical extracts: follow the pattern of the botanical name in Latin that we saw earlier:

• Camellia Sinensis Leaf Extract provides antioxidants from green tea. Punica Granatum Extract provides polyphenols from pomegranate. Centella Asiatica Extract provides madecassoside and asiaticoside, with calming and repairing action.

Peptides: have Peptide in their name or the prefix Palmitoyl:

• Palmitoyl Tripeptide-1, Acetyl Hexapeptide-3, Copper Tripeptide-1. These are anti-aging actives with action on collagen and firmness, common in high-end serums.

As we said at the beginning of this guide, the difference between an effective active and a decorative one is not in the name but in the concentration. A botanical extract at 0.001% on the list does almost nothing. The order in the INCI remains the key to evaluating whether an active is in a relevant amount or simply to justify a claim on the packaging.

A summary to keep in mind

With these keys, you can read any INCI with good judgment without having to look up every ingredient:

• Aqua at the beginning: water-based, needs preservatives.
• Oil/Extract/Butter with a botanical name in Latin before: plant ingredient.
• -ol: can be fatty alcohol (good), volatile alcohol (with caution) or active (depends on which one).
• -ate/-ite: salt or ester, variable function.
• SLS/SLES: harsh surfactants.
• -cone/-siloxane: silicones, we do not recommend them.
• -paraben: preservative under debate. Our advice: avoid it.
• CI + number: colorant, variable origin.
• Declared allergens (Limonene, Linalool...): fragrance components to consider for reactive skin.
• Actives: proper name in English without a systematic suffix: likely an active.

Reading the INCI and understanding the ingredients will help us know what we put on our skin, hair, or mouth, regardless of what is written on the front of the packaging. The front sells. The INCI informs.

With the three parts of this guide, you have the tools to make informed decisions: understand the logic of the list, recognize groups of ingredients by their function, and identify them by their name. With practice, patterns become automatic, and reading becomes quick.

The goal is not to generate distrust or turn every purchase into an exam. It is to give you context to choose better, to access real information and not just marketing claims. That's what we try to do at CUIDA-T with every product in the catalog: that the INCI supports what the label says, without unnecessary fillers.

To delve deeper into some of the mentioned ingredients, you will find them in our ingredient glossary or the Learn more fact sheets.