Most people have never read an INCI list. That’s probably because they don’t know how to read it and why it's worth reading.

INCI (International Nomenclature of Cosmetic Ingredients) is the standardised system for naming cosmetic ingredients, mandatory in the EU under Regulation 1223/2009. Each ingredient appears under its Latin or chemical name. The order is not random: it runs from the ingredient present in the greatest quantity to the least. Ingredients below 1% may be listed in any order, but everything above 1% follows the strict hierarchy.

So: if "Aqua" is first, you know water is present in greater quantity than everything else. Everything after it is less. Everything after it is considerably less.

Reading and deciphering the INCI list is one of the most straightforwardly useful things you can do for your skin.

Water isn't simply a cheap filler. It performs real functions in conventional formulas.

It acts as a solvent, dissolving water-soluble ingredients and making them accessible. It provides the product with texture and spreadability. Without it, most lotions and serums would be impossibly thick or greasy. It enables even distribution across the skin. It allows oil and water components to be combined into a stable emulsion.

Water does these things well so the question isn't whether it works but rather, what proproportion of the product does it occupy, and what's left for everything else? What are the other components that it imposes on the formula and do they bring any value to to the skin/hair?

According to data from cosmetic supplier Univar Solutions and the French cosmetics industry observatory CosméticOBS, a typical cream contains between 60 and 85% water. Lotions reach up to 90%. Shower gels and shampoos — up to 95%.

Take a moment sink that in.

If your cream is 80% water, every other ingredient including those claimed to hydrate, regenerate, smooth or nourish lives in the remaining 20%. Every active ingredient is diluted into those percentages.

The INCI list doesn't show specific percentage concentrations, only order. So even if you see hyaluronic acid, peptides, botanical oils or plant extracts in third or fourth position, you don't know whether their concentration is 5% or 0.05%. The only thing you know with certainty is that water is present in a greater quantity than anything else.

The order is transparent. The concentration is not.

Water does something that rarely gets discussed openly in marketing materials: it puts the formula at risk of microbial contamination.

That’s not because manufacturers are negligent. Microorganisms such as bacteria, yeasts, molds need water to grow. This is basic biology. Cosmetics containing water are a potential growth medium for pathogens and therefore require preservation.

From this follows a chain: water → risk of microbial growth → need for preservatives → additional INCI entries → longer ingredient list → greater potential for reaction in sensitive skin or scalp.

Preservatives themselves aren't the problem. EU Regulation 1223/2009 on cosmetic products, Annex V, regulates them strictly, and only approved substances are permitted. The issue is the logic: water in the formula makes them necessary. And every additional ingredient is an additional point of potential incompatibility, particularly for people with sensitive skin types.

Beyond preservatives, water-based emulsions also require emulsifiers. Those are ingredients whose sole purpose is to hold the oil and water phases together in a stable mixture. Without them, the emulsion separates. Their presence is a direct consequence of water's presence. Remove the water and the need for emulsifiers disappears with it.

Here's something that's less well known outside scientific circles but explains quite a lot.

In 1957, Australian microbiologist W.J. Scott published foundational work establishing that microbial growth is governed not by the total water content of a product, but by what's called water activity (Aw). Water activity is the amount of free, unbound water available to microorganisms. Scott identified minimum Aw thresholds for different types of microorganisms concluding: no bacteria, yeasts or molds can grow below Aw 0.6 [3].

Pure water has Aw = 1.0. A typical cream with 70% water has Aw around 0.98 — an ideal microbial growth environment. Anhydrous solid products — with no free water — have Aw well below 0.6.

Solid waterless products don’t have conditions for growth being below the water activity threshold. 

When a solid product gets wet during use in the shower, it's wet on the surface only for a limited time. Then it dries. The loss of surface water means the loss of the environment microorganisms need.

When water is removed from a formula, several things happen simultaneously.

First, concentration. If active ingredients are diluted into 20% of a water-based formula, in an anhydrous formula they occupy 100% of the volume which speaks for a categorically different cosmetic action.

Second, emulsifiers become unnecessary. Without water, there's no need for ingredients whose sole function is holding oil and water together. The INCI list shortens meaningfully, and that’s good news for your skin and hair.

Third, preservation becomes unnecessary by chemistry (not by marketing decision). Low water activity means that the environment for microbial growth doesn't exist. Adding a preservative to an anhydrous product would be like installing a lock on a gate in an open field.

Fourth, the stability of active ingredients improves. Some plant extracts and active compounds degrade more slowly in a waterless environment, because hydrolysis — one of the primary mechanisms of chemical breakdown — requires water to occur.

One more thing worth examining: the economics.

When comparing the price of an anhydrous product with a conventional equivalent, comparing the sticker price is the wrong metric. The more accurate question is: what is the cost per effective dose of active ingredients?

A YOGHHAIR solid shampoo of 110g typically replaces four to five 250ml bottles of liquid shampoo under normal (twice weekly wash) frequency of use. The real cost per wash is substantially lower, even when the price per gram looks higher at first glance.

Add the higher concentration of active ingredients to that calculation, and the arithmetic shifts further. You pay more for the unit but get more from the dose.

YOGH’s line is entirely solid, formulated without adding water to any product, therefore all the other components necessary for the product, not for the skin/hair. That’s our choice not because it's trendy or sounds good in marketing copy. Without water the formula is more concentrated, stable for years, simpler, and more wholesome.

Now, when you read the INCI of a YOGH product and don't find "Aqua", you know exactly what that means. Every ingredient in the list is there because it works with a concrete cosmetic benefit for the skin and hair. None of them is there to dilute the others.