Pyrithione zinc has long been a go-to active ingredient in the treatment of dandruff and seborrheic dermatitis. However, regulatory action in the European Union has placed it under scrutiny. As of March 1, 2022, Pyrithione zinc has been banned in cosmetics across the EU due to its classification as a Category 1B reproductive toxicant by the European Chemicals Agency. This action followed a precautionary approach in the context of the EU Cosmetics Regulation, which prohibits the use of substances with carcinogenic, mutagenic, or reprotoxic  properties unless considered safe by the Scientific Committee on Consumer Safety.

European Regulations

The SCCS did review Pyrithione zinc and found that it is safe for use in rinse-off hair products at concentrations up to 1%. However, it also expressed concern over its potential neurotoxic and environmental effects. Ultimately, the lack of new safety data addressing those concerns led to the EU’s decision not to reauthorize it, resulting in a ban that has disrupted availability of Pyrithione zinc-based shampoos in European markets.

Regulations in the United States 

In contrast, the United States Food and Drug Administration continues to allow ZPT in over-the-counter treatments for dandruff and seborrheic dermatitis, with formulations typically containing up to 2% for rinse-off products. The Cosmetic Ingredient Review  panel deferred a separate safety evaluation, citing the ingredient's inclusion in FDA-monograph products. There is currently no comparable regulatory push in the U.S. to reclassify or restrict ZPT based on the reproductive toxicity concerns raised by European authorities.

My Conclusion

Personally as a physician, it’s important to reconcile the differing global regulatory stances with available clinical data. Despite the EU’s conservative regulatory action, no significant post-market safety concerns have been documented in North America.  Still, patients who are pregnant or trying to conceive, or are wary of using PZT may benefit from alternative treatments, thus I recommend those to lean towards 1 or 2% Ketoconazole based shampoos. Ongoing surveillance and updated toxicological reviews are warranted to fully clarify the long-term safety profile of ZPT in therapeutic use.

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Medically Reviewed By

Dr. Khanna is a distinguished family medicine physician who brings a wealth of expertise by offering insightful and practical advice on a wide range of health concerns related to hair loss and dandruff. His experience in primary care gives him in-depth knowledge on managing common dermatological issues, including dandruff. Understanding the interplay between skin health, lifestyle factors, and medical conditions allows him to provide effective treatment strategies, from recommending medicated shampoos to addressing underlying causes such as seborrheic dermatitis or fungal infections. He provides a valuable resource for both patients and healthcare professionals, reinforcing the importance of comprehensive, patient-centered care.

Dr. Deepak Khanna D.O

Family Medicine Physician

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