Pyrithione Zinc for Hair Loss and Dandruff: What the Research Shows

Pyrithione zinc (ZPT) is a common anti-dandruff ingredient, and it has one randomized trial for hair: in 200 men with androgenetic alopecia, a 1% pyrithione zinc shampoo gave a modest, sustained increase in hair count compared with placebo shampoo, about half that of 5% minoxidil.

Here's what the trial found, what the dandruff research shows, and the allergy caution.

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Key Takeaways

• In a 6-month, 200-man randomized trial, daily 1% pyrithione zinc shampoo significantly increased total hair count versus placebo shampoo after 9 weeks, and the benefit was maintained to 26 weeks.
• The increase with pyrithione zinc was slightly less than half that with 5% minoxidil, and using both together showed no added advantage.
• A meta-analysis of 17 studies (2,088 people) found 1% ZnPT shampoo reduced dandruff more than a non-anti-dandruff shampoo, with a stronger response in men than women.
• Allergy to zinc pyrithione has been reported.

What Is Pyrithione Zinc?

Pyrithione zinc is a common anti-dandruff ingredient. The studies below used it in 1% shampoos.

Does Pyrithione Zinc Help Hair Growth?

In one trial, modestly. The trial tested a 1% shampoo used daily, in men with early to moderate baldness. It's a single trial, so larger studies and women are not covered.

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Using It Sensibly

• For dandruff: it's a reasonable anti-dandruff active, with trial support.
• For hair growth: treat it as an add-on with modest evidence, and see a dermatologist for the cause of thinning.
• Stop if irritated. Allergy has been reported.

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What The Research Shows

Hair Count Trial

In a 6-month randomized, investigator-blinded study of 200 men aged 18 to 49 with Hamilton-Norwood type III vertex or type IV baldness, a daily 1% pyrithione zinc shampoo, 5% minoxidil solution, placebo shampoo, or both active treatments were compared. Total hair counts rose significantly with pyrithione zinc, minoxidil and the combination versus placebo after 9 weeks. The increase with pyrithione zinc was slightly less than half that of minoxidil and was maintained over 26 weeks. There was no advantage to using both. The authors concluded it gave a modest, sustained improvement in hair growth (Berger et al., 2003).

Dandruff Research

A meta-analysis of 17 half-head, double-blind, randomized studies (2,088 people) compared 1% ZnPT shampoo with a non-anti-dandruff shampoo over 4 weeks. The response to ZnPT was greater in men than in women, with a 4-week between-treatment difference in flake score of -17.5 in men and -11.1 in women. The authors linked this to sex-related differences in the scalp's stratum corneum (Collins et al., 2018).

Allergy

A 1985 case report was titled "Zinc pyrithione (Zinc Omadine) allergy" (Brandrup & Menné, 1985). The PubMed record has no abstract, so we only report the title.

See also: Derma Roller for Hair Growth: What the Research Shows & Safety · Milk Thistle for Hair: What the Research Shows

If your hair is thinning, see our guide to shampoo for thinning hair.

Frequently Asked Questions

Does pyrithione zinc help hair loss?

In a 200-man trial, a 1% pyrithione zinc shampoo modestly increased hair count versus placebo. It was less effective than 5% minoxidil.

Does pyrithione zinc work for dandruff?

A meta-analysis of 17 studies found 1% ZnPT shampoo reduced dandruff more than a non-anti-dandruff shampoo.

Can you be allergic to pyrithione zinc?

Allergy has been reported. Stop use if you notice irritation and see a doctor.

References

1. Berger RS, Fu JL, Smiles KA, et al. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial. Br J Dermatol. 2003. PubMed
2. Collins LZ, Baines FL, Matheson JR, et al. Sex-related differences in response to zinc pyrithione shampoo vs. non-anti-dandruff shampoo. Int J Cosmet Sci. 2018. PubMed
3. Brandrup F, Menné T. Zinc pyrithione (Zinc Omadine) allergy. Contact Dermatitis. 1985. PubMed