To achieve a truly clean scalp and prevent a greasy appearance, the key lies in a thorough washing technique: use a generous amount of product, perform a double shampoo, and ensure uniform distribution across the entire scalp by sectioning the hair.

noli's read

The community strongly converges on this approach, which is validated by the practical experience of professionals and users alike. Scientifically, cleansing the scalp relies on the removal of lipids (sebum) and debris by the surfactants contained in shampoo. 'Double shampooing' is a common practice in cosmetology: the first wash removes surface grime and sebum, while the second allows the cleansing agents to act more effectively on the bare skin. The importance of distribution and rinsing, as mentioned by users, is crucial because product residue or incomplete cleaning of dense areas (such as the nape of the neck) can create a film that looks greasy. While science confirms the effectiveness of surfactants in emulsifying oil, the ideal frequency and precise quantity remain subjective and depend on individual physiology (observational). There is no rigorous evidence establishing a universal 'single dose,' as this depends on the concentration of the product, water hardness, and natural sebum production.

the sources

1. 1r/HaircareScience