Water is the first ingredient in your cosmetics.Here's what that means.

Most people have never read an INCI list—not because they don’t care, but because they don’t know why it matters or how to interpret it. Instead, they rely on a brand’s marketing promises.

INCI (International Nomenclature of Cosmetic Ingredients) is the standardized system for naming cosmetic ingredients, mandatory in the European Union under Regulation (EC) No. 1223/2009. Every ingredient is listed using its Latin or chemical name.

The order of ingredients is not random. Ingredients are listed from the highest concentration to the lowest. Ingredients present at less than 1% may be listed in any order, but everything above 1% must follow a strict hierarchy.

Therefore, if “Aqua” appears first, you know that water is present in a greater amount than any other ingredient in the product. Everything listed after it is present in a smaller quantity, and ingredients that appear much further down the list are present in significantly smaller amounts.

That is precisely why learning to read an INCI list is one of the smartest and most useful things you can do for your skin.

Let’s start with an honest statement: water is not just a cheap filler. It serves real functions in conventional cosmetic formulations.

It acts as a solvent, dissolving water-soluble ingredients and making them available. It gives products a pleasant, fluid consistency, without which lotions and serums would be uncomfortably thick or oily. It helps distribute the product evenly across the skin. It also allows oil-based and water-based components to be combined into a stable emulsion.

Water performs these functions well. So the question here is not whether water works, but what proportion of the product it occupies and what remains for the other components. What are the other components that its presence necessitates?

According to data from cosmetic ingredient supplier Univar Solutions and the cosmetics industry observatory CosméticOBS, a typical cream contains between 60% and 85% water. A lotion can contain up to 90%. Shower gels and shampoos can contain up to 95%.

Let’s pause for a moment.

If a cream is 80% water, then all the remaining ingredients—including those claimed to hydrate, regenerate, smooth, or nourish the skin—are concentrated within the remaining 20%. Every active ingredient is diluted within that fraction.

INCI lists do not disclose the exact percentage concentrations of ingredients; they only reveal their order. Even if you see hyaluronic acid, peptides, or botanical extracts listed third or fourth, you do not know whether their concentration is 5% or 0.05%. The only thing you know with certainty is that water is present in a greater amount than anything else.

The order is transparent, but the concentration of the ingredients that actually deliver cosmetic benefits is not.

Water does something that is rarely discussed openly: it puts the formula at risk of microbial contamination.

The reason is not that manufacturers are careless, but that microorganisms such as bacteria, yeasts, and molds need water to thrive. This is basic biology. Cosmetics that contain water are a potentially fertile environment for the growth of pathogens and therefore require preservation.

From this arises a chain of consequences:

water → risk of microbial growth → need for preservatives → additional ingredients in the INCI list → a longer ingredient list → greater potential for reactions in sensitive skin or scalps.

Preservatives themselves are not the problem. They are strictly regulated under Annex V of EU Cosmetics Regulation (EC) No. 1223/2009, and only approved preservatives are permitted. The issue lies in the logic: water in the formula necessitates their presence, and every additional ingredient is another potential point of incompatibility, especially for people with sensitive skin.

In addition to preservatives, water-based emulsions also require emulsifiers. These are ingredients whose sole purpose is to bind oils and water together into a stable mixture called an emulsion. Without them, the emulsion separates. Their presence is a direct consequence of the presence of water. Remove the water, and the need for emulsifiers disappears along with it.

This brings us to something that is less well known outside scientific circles, but explains a great deal.

In 1957, the Australian microbiologist W. J. Scott published a foundational study showing that microbial growth is determined not by the total amount of water in a product, but by what is known as water activity (Aw)—the amount of free, unbound water available to microorganisms. Scott established minimum Aw thresholds for different types of microorganisms. The conclusion: below an Aw of 0.6, neither bacteria, yeasts, nor molds can grow.

Pure water has an Aw of 1.0. A typical cream containing 70% water has an Aw of around 0.98—an ideal environment for microbial growth. Anhydrous solid products, meaning products without free water, have an Aw well below the 0.6 threshold and therefore do not provide conditions that support microbial growth.

When a solid product becomes wet during use in the shower, it is only wet on the surface and only for a limited period of time, after which it dries. The loss of surface water means the loss of the environment that unwanted microorganisms need in order to multiply.

When water disappears from a formula, several things happen at the same time.

First, it affects concentration. If the active ingredients in a water-based formula are diluted within the remaining 20% of the composition, then in an anhydrous formula they account for 100% of the product's volume.

Second, emulsifiers become unnecessary. Without water, there is no need for ingredients whose sole purpose is to keep the oil and water phases bound together in a stable mixture. The INCI list becomes significantly shorter.

Third, preservation is no longer required by necessity rather than by marketing choice. Low water activity means that the environment needed for microbial growth simply does not exist. Adding a preservative to a solid, water-free product is like putting a lock on a gate in the middle of an open field.

Fourth, active ingredients such as botanical extracts and other functional compounds tend to be more stable in an anhydrous environment, because they degrade more slowly. One of the main mechanisms of chemical degradation—hydrolysis—requires water to occur.

The last thing worth considering is the economic aspect.

When you compare the price of a YOGH anhydrous solid product with that of a conventional equivalent, you are comparing the wrong metric. The more accurate question is: what is the cost per unit dose of active ingredients?

If a 110 g YOGHHAIR solid shampoo replaces 4–5 bottles of 250 ml liquid shampoo (a standard estimate for normal use at twice per week), the actual cost per use is significantly lower, even if the price per gram appears higher.

When this is combined with a higher concentration of active ingredients, the mathematics shifts.

You may pay more for the package, but you receive more in every dose.

At YOGH, we do not add water to any of our products and formulate our entire range in solid form. We did not choose this approach because it is trendy or sounds good in marketing copy, but because it allows us to create more concentrated, more stable, and more minimalist products for skin and hair, with a lower likelihood of disrupting the protective barrier or triggering irritation and other issues.

Now, when you read the INCI list of a YOGH product and do not find “Aqua,” you know exactly what that means. Every ingredient in the list is there because it serves a purpose. None are there to dilute the rest of the formula or to improve the product’s texture without providing a benefit to the skin or hair.

Only cosmetically active ingredients are included in the formulation, each with a specific function for the skin or hair.