Zinc Pyrithione

The active anti-dandruff ingredient in medicated shampoos, used at 1% or 2% to reduce Malassezia yeast and flaking. It is well studied and considered safe in rinse-off use; EU rules cap leave-on hair products because it is more irritating with prolonged skin contact, which is why it is formulated into shampoos meant to be rinsed out.

Cosmetic information for general education, not medical advice. Concern is graded on cited evidence, never on hazard-score lists. See how we score.