ribogrow receives Dermatest® "Excellent" – 0 out of 30 subjects with skin reaction on sensitive skin

In March 2026, we had the ribogrow Hair Booster Tonic and Hair Booster Serum tested for skin compatibility by Dermatest GmbH, an independent dermatological testing institute in Münster. Both products were certified with the rating "Excellent". Not a single one of the 30 male and female subjects showed a relevant skin reaction in a test conducted exclusively with individuals with sensitive skin.

What is the Dermatest® Patch Test?

The patch test is the internationally established standard procedure for testing the skin compatibility of cosmetic products. It was developed back in 1895 by the German physician Joseph Jadassohn and is now standardized by international guidelines, including DIN EN ISO 10993-23:2021 and the recommendations of the German Dermatological Society (DDG).

The procedure works as follows: The undiluted test product is applied occlusively, i.e., under a sealed patch, to the skin for 24 hours. Subsequently, dermatologists assess the skin reaction at three time points: 24, 48, and 72 hours after application. The occlusive application creates more intense conditions than the actual product use in everyday life. The test is deliberately designed to be more challenging.

Assessment scale according to EN ISO 10993-23:2021
0 – No reaction
1 – Weak positive reaction (slight erythema)
2 – Moderate positive reaction (distinct erythema)
3 – Strong positive reaction (strong erythema with edema)

Products fail the test if 10% or more of the subjects show a product-related skin reaction.

Why sensitive skin is the decisive factor

The study was conducted exclusively with subjects who had sensitive skin. This is not a matter of course; many skin compatibility tests are carried out with healthy-skinned subjects without known sensitivities. Sensitive skin reacts faster and more strongly to external influences: redness, tightness, and irritation occur more easily.

The fact that ribogrow did not cause a single relevant reaction even under these conditions is the most conclusive result possible for anyone who relies on compatibility in hair care products.

A strong signal

ribogrow was deliberately formulated without fragrances, colorants, and unnecessary additives. Fragrances and colorants, even natural ones, are among the most common triggers of contact allergies. About one in five people are sensitive to them, often without knowing it. These ingredients were therefore removed from the formula from the outset.

The three active ingredients in ribogrow: 2-deoxy-D-ribose (2DDR), Pisum Sativum (organic pea sprout extract), and caffeine were chosen not only for their effectiveness against hair loss but also for their compatibility profile. 2DDR is an endogenous molecule that is a natural component of DNA in every human cell. Pisum Sativum is a plant extract. Caffeine is a dermatologically researched substance for decades. None of these active ingredients interfere with the hormonal balance and none are known to cause skin irritation.

The Dermatest result is not surprising news. It is the external, independent confirmation of what was a fundamental principle in ribogrow's product development from the very beginning: effectiveness and compatibility are not mutually exclusive.

Details

Testing Institute: Dermatest GmbH, Münster (ISO 9001, TÜV Rheinland certified)
Tested Products: ribogrow Hair Booster Tonic · ribogrow Hair Booster Serum
Study Number: ST-ET-2026-00041
Subjects: 30 individuals with sensitive skin, aged 18 and over
Method: Patch test, occlusive, 24h application, undiluted
Measurement Time Points: 24h, 48h, and 72h after application
Result: 0 out of 30 subjects with relevant reaction
Dermatest® Rating: "Excellent" – dermatologically tested (03/2026)