Dermatologically Tested. What does it mean?

It's one of the most common claims on cosmetic labels, yet it's not at all required by law: we're talking about the famous "Dermatologically Tested".

But what does it mean? This statement, when present on the label, informs the consumer that the manufacturing company has commissioned a certified laboratory (or a specialized dermatologist) to perform a skin irritation test on the cosmetic product before it is placed on the market.

Therefore, the way the skin might react to the ingredients of a product intended for external use, i.e., application to the skin, and the statistical probability of causing skin irritation were assessed.

Since, as mentioned, it is not legally required to perform such a test, there is still no standard skin test today, but there are different models and different ways to proceed to give this guarantee to the consumer.

How does the test take place?

It is usually carried out in specialized institutes or universities. It consists of a patch test, i.e., applying a small amount of the product to the epidermis of a sample of volunteers with a patch, to evaluate their reaction following occlusion (the patch is usually applied to the back and remains for 48 hours).

Normally, there are at least 20 volunteers, over 18 years of age, in good general health and without any particular skin conditions.

The test usually evaluates the reaction and the number of irritative responses at 15 minutes and 24 hours after the patch is removed.

At the end of the test, the results are released, including the ratings and the degree of skin compatibility of the product, and then the "Dermatologically Tested" certificate is issued (which in itself would only attest that a skin tolerability test has been carried out, without a qualitative evaluation).

It is then up to the companies, in the event that a high percentage of skin reactions is found, to assess whether to make changes to the product formulation before launching it on the market or to act differently.

There are also different types of patch tests, such as semi-occlusive tests (suitable for products that have brief skin contact in their intended use) or patch tests for sensitive skin (ideal for products to be applied to delicate areas such as the face, or for particularly irritable skin).

One last, but important, clarification: this statement in Europe never refers to tests carried out on animals. According to European cosmetic legislation, in fact, the safety and efficacy of products must be tested on healthy human volunteers in certified clinical laboratories.