To assess the efficacy and compatibility of anti-dandruff products, final formulations are tested on test subjects with dandruff affection. This is done either in a half-head test or in a whole-head test. In the half-head test two products are applied by in-house hairdressers in a temperature-controlled salon. In the whole-head test the products can either be used by the test subjects at home (home in-use test) or be applied by our in-house hairdressers in our salon. The test products are normally used for four weeks.

The dandruff status is determined subjectively by trained hairdressers and the test subjects themselves. Additionally, it is possible to determine the amount of dandruff quantitatively by combing out the dandruff onto a glass plate, which is subsequently analyzed by an image analysis system.