At ORY®, we believe you should know what’s in your products and why. This page lists the published research behind what we say about zinc pyrithione (pyrithione zinc). Each section starts with our claim, then tells you how well the research supports it, then lists the sources so you can read them yourself.
Important: Zinc pyrithione (listed on U.S. drug labels as pyrithione zinc) is an FDA over-the-counter (OTC) drug ingredient for dandruff and seborrheic dermatitis. ORY® products that contain it for dandruff control are OTC drugs, not cosmetics, and carry a Drug Facts label. Zinc pyrithione has been prohibited in cosmetics in the European Union since March 1, 2022; ORY® does not sell zinc pyrithione products into the EU.
How to read this page Supported — backed by peer-reviewed research or official safety reviews. Supported, with caveats — the research points this way, but mostly from laboratory or animal studies, or at different strengths than ORY® uses. Limited evidence — little or no published research yet. We say so openly. |
1. General Description and Role
Claim: Zinc pyrithione is an antifungal ingredient that FDA allows in OTC products to help control dandruff and seborrheic dermatitis. In ORY® OTC shampoos, it is the active ingredient for dandruff control. |
Verification: Supported. FDA’s dandruff drug rule lists pyrithione zinc at 0.3–2% in wash-off products and 0.1–0.25% in leave-on products. Products making these claims must follow FDA OTC drug requirements, including Drug Facts labeling.
Citations:
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- What it shows: FDA dandruff drug rule.
- U.S. Food and Drug Administration. 21 CFR 201.66 — Format and content requirements for over-the-counter (OTC) drug product labeling (Drug Facts). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-C/section-201.66
- What it shows: FDA Drug Facts labeling rule.
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
2. Composition and Production
Claim: Zinc pyrithione is a synthetic complex of zinc with two pyrithione molecules, supplied as an insoluble powder or dispersion that must be suspended in the shampoo. |
Verification: Supported. Lab research shows it slows yeast growth by bringing copper into yeast cells.
Citations:
- Reeder, N. L., Kaplan, J., Xu, J., et al. (2011). Zinc pyrithione inhibits yeast growth through copper influx and inactivation of iron-sulfur proteins. Antimicrobial Agents and Chemotherapy, 55(12), 5753–5760. https://doi.org/10.1128/AAC.00724-11
- What it shows: Lab study of mechanism.
- Reeder, N. L., Kaplan, J., Xu, J., et al. (2011). Zinc pyrithione inhibits yeast growth through copper influx and inactivation of iron-sulfur proteins. Antimicrobial Agents and Chemotherapy, 55(12), 5753–5760. https://doi.org/10.1128/AAC.00724-11
3. Skin Type Suitability
Claim: ORY® uses zinc pyrithione only in rinse-off OTC products, not in general skincare. |
Verification: Supported. Any ORY® body or face wash with zinc pyrithione is labeled as an OTC drug and used only as directed on the Drug Facts label.
Citations:
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- What it shows: FDA dandruff and seborrheic dermatitis rule.
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
4. Hair and Scalp Suitability
Claim: In ORY® OTC shampoos, zinc pyrithione helps control dandruff. |
Verification: Supported. In a multicenter randomized trial, 1% zinc pyrithione shampoo improved severe dandruff and seborrheic dermatitis, though 2% ketoconazole performed somewhat better. A randomized trial also reported a modest increase in hair count with 1% zinc pyrithione shampoo; hair-growth claims are not part of FDA’s dandruff rule, and ORY® does not make them.
Citations:
- Piérard-Franchimont, C., Goffin, V., Decroix, J., & Piérard, G. E. (2002). A multicenter randomized trial of ketoconazole 2% and zinc pyrithione 1% shampoos in severe dandruff and seborrheic dermatitis. Skin Pharmacology and Applied Skin Physiology, 15(6), 434–441. https://doi.org/10.1159/000066452
- What it shows: Randomized trial in dandruff and seborrheic dermatitis.
- Berger, R. S., Fu, J. L., Smiles, K. A., et al. (2003). The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: A randomized controlled trial. British Journal of Dermatology, 149(2), 354–362. https://doi.org/10.1046/j.1365-2133.2003.05435.x
- What it shows: Randomized trial of hair density (not a permitted claim).
- U.S. Food and Drug Administration. 21 CFR 310.527 — Drug products offered over-the-counter for external use as hair growers or for hair loss prevention. https://www.law.cornell.edu/cfr/text/21/310.527
- What it shows: FDA hair-growth rule.
- Piérard-Franchimont, C., Goffin, V., Decroix, J., & Piérard, G. E. (2002). A multicenter randomized trial of ketoconazole 2% and zinc pyrithione 1% shampoos in severe dandruff and seborrheic dermatitis. Skin Pharmacology and Applied Skin Physiology, 15(6), 434–441. https://doi.org/10.1159/000066452
5. Benefits
Claim: Used as directed, ORY® zinc pyrithione shampoos help control the flaking and itching of dandruff. |
Verification: Supported. This is an FDA-permitted OTC drug claim when the product meets the dandruff rule and is labeled with Drug Facts.
Citations:
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- What it shows: Permitted claims.
- Borda, L. J., & Wikramanayake, T. C. (2015). Seborrheic dermatitis and dandruff: A comprehensive review. Journal of Clinical and Investigative Dermatology, 3(2). https://doi.org/10.13188/2373-1044.1000019
- What it shows: Review of dandruff and seborrheic dermatitis.
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
6. Use Across ORY® Product Lines
Claim: Zinc pyrithione is used only in U.S. OTC rinse-off products: shampoos, some body washes, and syndet shampoo bars. |
Verification: Supported. It is not used in cosmetics, leave-on skincare, or cold-process soap, and is not sold in the EU.
| Product line | Typical level | How ORY® uses it |
| Skincare | 0.95–2% (OTC only) | Rinse-off seborrheic dermatitis washes labeled as OTC drugs (U.S. only). |
| Haircare | 1–2% (OTC only) | OTC dandruff shampoos with Drug Facts (U.S. only). |
| Handmade Soap line | 1–2% (OTC only) | Syndet shampoo bars labeled as OTC drugs; not cold-process bars. |
| Cosmetics | Not used | — |
Citations:
- European Commission. Commission Regulation (EU) 2021/1902 amending Annexes II, III and V to Regulation (EC) No 1223/2009 (zinc pyrithione prohibited in all cosmetic products, including rinse-off hair products, from 1 March 2022). Official Journal of the European Union, L 387, 120. https://eur-lex.europa.eu/eli/reg/2021/1902/oj
- What it shows: EU prohibition.
- U.S. Food and Drug Administration. 21 CFR 701.20 — Definition of “soap” (only true soap, made mainly of alkali salts of fatty acids and sold only as soap, is exempt from cosmetic rules). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-G/part-701/subpart-B/section-701.20
- What it shows: FDA definition of soap; other bars are cosmetics.
- European Commission. Commission Regulation (EU) 2021/1902 amending Annexes II, III and V to Regulation (EC) No 1223/2009 (zinc pyrithione prohibited in all cosmetic products, including rinse-off hair products, from 1 March 2022). Official Journal of the European Union, L 387, 120. https://eur-lex.europa.eu/eli/reg/2021/1902/oj
7. Pros
Claim: An FDA-recognized dandruff active with randomized-trial evidence. |
Verification: Supported. Supported by FDA’s rule and clinical trials.
Citations:
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- What it shows: FDA rule.
- Piérard-Franchimont, C., Goffin, V., Decroix, J., & Piérard, G. E. (2002). A multicenter randomized trial of ketoconazole 2% and zinc pyrithione 1% shampoos in severe dandruff and seborrheic dermatitis. Skin Pharmacology and Applied Skin Physiology, 15(6), 434–441. https://doi.org/10.1159/000066452
- What it shows: Trial.
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
8. Cons
Claim: Zinc pyrithione products are OTC drugs with added requirements, and the ingredient is banned in EU cosmetics. |
Verification: Supported. We list these limits so you have the full picture:
- OTC drug rules. Drug Facts labeling, drug registration and listing, and drug manufacturing (cGMP) standards apply.
- EU ban. Prohibited in EU cosmetics since 2022 (classified as toxic to reproduction).
- Insoluble. Needs suspension.
- Eye irritation. Keep out of eyes.
Citations:
- U.S. Food and Drug Administration. 21 CFR 201.66 — Format and content requirements for over-the-counter (OTC) drug product labeling (Drug Facts). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-C/section-201.66
- What it shows: Drug labeling.
- European Commission. Commission Regulation (EU) 2021/1902 amending Annexes II, III and V to Regulation (EC) No 1223/2009 (zinc pyrithione prohibited in all cosmetic products, including rinse-off hair products, from 1 March 2022). Official Journal of the European Union, L 387, 120. https://eur-lex.europa.eu/eli/reg/2021/1902/oj
- What it shows: EU ban.
- U.S. Food and Drug Administration. 21 CFR 201.66 — Format and content requirements for over-the-counter (OTC) drug product labeling (Drug Facts). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-C/section-201.66
9. Safety Notes
Claim: Patch test before use; for external use only. |
Verification: Supported. Follow these precautions:
- Patch test any new product on a small area for 24–48 hours before full use.
- Follow the Drug Facts label. Stop use and ask a doctor if the condition worsens or does not improve after regular use.
- Stop use if redness, burning, itching, or rash occurs, and talk to a healthcare provider.
- For external use only. Avoid the eyes unless the product is made for the eye area.
- If you are pregnant, nursing, have a medical condition, or are buying for a child, ask a healthcare provider before use.
Citations:
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- What it shows: FDA rule.
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
10. Product-line notes
- ORY® Skincare: Zinc pyrithione body and face washes are OTC drugs; follow the Drug Facts label. For external use only.
- ORY® Haircare: Zinc pyrithione shampoos are OTC dandruff drugs; follow the Drug Facts label. Not intended to promote hair growth or prevent hair loss. If your scalp condition is severe or does not improve, see a dermatologist.
- ORY® Handmade Soap line: Zinc pyrithione is used only in syndet shampoo bars labeled as OTC drugs, never in cold-process soap.
- ORY® Cosmetics: Zinc pyrithione is not used in ORY® cosmetics.
11. References
Peer-reviewed research
- Berger, R. S., Fu, J. L., Smiles, K. A., et al. (2003). The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: A randomized controlled trial. British Journal of Dermatology, 149(2), 354–362. https://doi.org/10.1046/j.1365-2133.2003.05435.x
- Borda, L. J., & Wikramanayake, T. C. (2015). Seborrheic dermatitis and dandruff: A comprehensive review. Journal of Clinical and Investigative Dermatology, 3(2). https://doi.org/10.13188/2373-1044.1000019
- Piérard-Franchimont, C., Goffin, V., Decroix, J., & Piérard, G. E. (2002). A multicenter randomized trial of ketoconazole 2% and zinc pyrithione 1% shampoos in severe dandruff and seborrheic dermatitis. Skin Pharmacology and Applied Skin Physiology, 15(6), 434–441. https://doi.org/10.1159/000066452
- Reeder, N. L., Kaplan, J., Xu, J., et al. (2011). Zinc pyrithione inhibits yeast growth through copper influx and inactivation of iron-sulfur proteins. Antimicrobial Agents and Chemotherapy, 55(12), 5753–5760. https://doi.org/10.1128/AAC.00724-11
Government and regulatory sources
- U.S. Food and Drug Administration. 21 CFR 358.710 — Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis (pyrithione zinc 0.3–2% in wash-off products, 0.1–0.25% in leave-on products for dandruff; climbazole and piroctone olamine are not listed). Now OTC Monograph M032. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-358/subpart-H/section-358.710
- U.S. Food and Drug Administration. 21 CFR 201.66 — Format and content requirements for over-the-counter (OTC) drug product labeling (Drug Facts). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-C/section-201.66
- European Commission. Commission Regulation (EU) 2021/1902 amending Annexes II, III and V to Regulation (EC) No 1223/2009 (zinc pyrithione prohibited in all cosmetic products, including rinse-off hair products, from 1 March 2022). Official Journal of the European Union, L 387, 120. https://eur-lex.europa.eu/eli/reg/2021/1902/oj
- U.S. Food and Drug Administration. 21 CFR 310.527 — Drug products offered over-the-counter for external use as hair growers or for hair loss prevention. https://www.law.cornell.edu/cfr/text/21/310.527
- U.S. Food and Drug Administration. 21 CFR 701.20 — Definition of “soap” (only true soap, made mainly of alkali salts of fatty acids and sold only as soap, is exempt from cosmetic rules). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-G/part-701/subpart-B/section-701.20
