How to read an INCI list: fairy dusting and underdosed active ingredients

You've tried to read the ingredients list of a cosmetic. A long list of incomprehensible names. So you trust the promise on the packaging, a rating on an app, or an influencer's opinion.

This is precisely where most routine mistakes begin.

An ingredient listed on the label is not necessarily present in a dose that makes any difference to your skin.

What the INCI list actually is

INCI (International Nomenclature of Cosmetic Ingredients) is the international coding system that identifies each cosmetic ingredient by a unique name — the same worldwide. Aqua for water, Retinol for retinol, Niacinamide for niacinamide.

In Europe, displaying the full INCI list is a regulatory obligation. This list follows a precise order: decreasing concentration, down to a threshold of 1%. In practice, the first three or four ingredients often make up 80% or more of the product's total composition.

What the INCI list tells you — and what it hides

What many don't know: below the 1% threshold, ingredients can be listed in any order. A manufacturer can therefore legally place a valuable active ingredient — retinol, vitamin C, peptides — in a visible position on the list, without that active ingredient being present at an effective concentration.

Cosmetic chemists have a name for this practice: "fairy dusting". This involves incorporating a tiny amount of a trendy active ingredient into a standard formula, just enough to display it on the label and use it as a marketing argument, but below the documented efficacy threshold for that active ingredient. This is all the more common because many valuable active ingredients — vitamin C, retinol, certain antioxidants — are expensive and fragile: overdosing them has no commercial interest, and their concentration degrades further after opening.

This is not an isolated case. It is a structural reality of the mass-market cosmetics industry.

Efficacy thresholds: what science says about concentrations

Niacinamide regulates sebum and improves texture from 4%, with documented effects on pigmentation between 5 and 10%. Below 2%, its effect is marginal.

Vitamin C in the form of L-ascorbic acid is effective between 10 and 20% according to dermatological publications. Beyond 20%, it becomes irritating without additional benefit. A 0.5% formula does nothing for your skin — except sell you a "vitamin C serum".

Retinol shows documented efficacy from 0.025% for sustained-release formulations, between 0.1 and 1% for standard formulations. A product that lists it in 25th position out of 30 ingredients probably does not contain a relevant concentration.

Hyaluronic acid: its effectiveness depends not only on concentration, but on molecular weight. Low molecular weight molecules penetrate the epidermis and provide deep hydration. High molecular weight molecules remain on the surface. A product can display "hyaluronic acid" without specifying which type — and therefore without you knowing what it actually does for your skin.

How to read an INCI list correctly: practical tips

Look at the first five ingredients. They make up the bulk of the formula. If the first five are water, glycerol, an emollient, a thickener, and a preservative, you have a basic product — regardless of the promise on the front of the packaging.

Identify the position of the claimed active ingredients. An active ingredient highlighted in the product name should ideally appear within the first ten ingredients to have a chance of being at a relevant dose.

Be wary of simplified rating applications. They can give an indication of the safety of certain ingredients, but they do not take into account your skin profile, actual concentrations, or the consistency of the formula. A perfect score does not mean an effective product for you.

The Paradermia approach

At Paradermia, our pharmacist audits each product before offering it: active ingredient position, probable concentrations, compatibility of ingredients with each other, relevance to different skin profiles. Products are selected for their actual formulation — active ingredients at effective doses, overall consistency — and integrated into protocols where each product has a specific role.

Frequently Asked Questions

How do I know if Paradermia products contain active ingredients at effective doses?
This is precisely the selection work carried out by our pharmacist before each listing. Each product is audited based on its actual INCI list: active ingredient position, formula consistency, relevance to the profiles for which it is recommended. You don't choose a well-rated product — you choose a validated product.

Should certain ingredients be avoided at all costs?
It all depends on your skin, the concentration, and the overall formulation. An ingredient is never absolutely good or bad — it's its suitability for your profile that determines whether it's right for you.

Are apps like Yuka or INCI Beauty reliable?
They are useful as a first awareness filter. However, their algorithms do not take into account actual concentrations or your specific skin profile. A perfect score can correspond to a product without effective active ingredients. A mediocre score can correspond to a product perfectly suited to your skin.