INCI Guide (I): what it is and how to interpret it

There's a list on every cosmetic product that most people ignore. It's in fine print, in Latin or technical English, and usually squeezed 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 is not.

What exactly is it?

INCI is the official, 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 in 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 is a nuance: above approximately 1% concentration, the order may no longer be strict. Ingredients in very small quantities—preservatives, fragrances, low-dose actives—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.

Actives at the end of the list are not necessarily useless. Some ingredients are very effective at low concentrations, such as niacinamide, retinol, and bakuchiol. Being at the end doesn't mean they do nothing; it means they are present in small amounts, which may 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 it as. Here are some examples from our catalog:

With a little practice, you'll recognize the common ones without thinking. And when you encounter one you don't know, you know where to look: in our Learn More section, we break them down one by one. There are also apps like INCI beauty that break down ingredients and classify them, 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's no single standard; each brand uses them in its own way, but the most common are:

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

Natural origin asterisk. Similar to the above but broader, indicating 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 when 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 the INCI doesn't tell you

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

Exact concentrations. Except for 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 cold-pressed virgin argan oil and a refined argan oil appear the same in the INCI. The difference is in the process, not the name.

The product's actual efficacy. An INCI full of interesting actives 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 a starting point, not the final verdict. It helps eliminate what you're clearly not interested in and better understand what's inside, but it doesn't replace your judgment or the experience of using the product.

Where to start

If you've never read an INCI, a good exercise is to pick up 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. That's 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 a significant amount. If they appear at the end, they are in trace amounts.

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

In the next article in this series, we delve into ingredient groups by function: humectants, emollients, occlusives, surfactants, and actives. This way, when you see a complete INCI, you'll know what each component does and what to look for based on your skin's needs.