Other Ingredients

Ketoconazole

Also known as: Nizoral, Ketoconazole 2%, Ketoconazole cream

The antifungal behind Nizoral — first-line for dandruff and seborrheic dermatitis, with a quiet anti-androgen bonus for hair.

By IngredientWiki Editorial Team
Fact-checked by IngredientWiki Editorial Team
Updated 2026-09-26
2 min read

In short

Ketoconazole is a broad-spectrum antifungal — available as OTC shampoo (1%) and prescription formulations (2% shampoo, creams) — and the first-line treatment for seborrheic dermatitis and dandruff, conditions driven by Malassezia yeast on the scalp. It kills the yeast and damps the inflammation it triggers, with trials showing significant clearance rates. The ingredient has a second, subtler role in hair-loss care: it weakly blocks androgens at the follicle, which is why ketoconazole shampoo is often stacked with minoxidil and finasteride in hair-loss regimens — an adjunct with modest but real supporting evidence.

Broad-spectrum azole antifungal
Targets Malassezia — the dandruff/seb-derm yeast
OTC 1% shampoo; prescription 2% and creams
Weak anti-androgen effect at the follicle — hair-loss adjunct

What is Ketoconazole?

Dandruff is mostly a yeast problem, and ketoconazole is the yeast's most effective over-the-counter enemy. Malassezia — a fungus living on everyone's scalp — overgrows and inflames the skin in susceptible people, producing the flakes and redness of seborrheic dermatitis; ketoconazole suppresses it directly, which is why dermatologists reach for Nizoral first. The ingredient's second career, as an anti-androgen adjunct in hair-loss stacks, is more niche but mechanistically sound, and it explains why the same blue bottle appears in both dandruff and hair-growth discussions.

Where it comes from

Natural sources

Not natural — a synthetic imidazole antifungal developed in the 1970s.

How it's made

Manufactured drug; formulated as shampoos, creams, foams, and (rarely now) oral tablets.

What it does in products

Benefits

Dandruff and seborrheic dermatitis

strong evidence

Randomized trials show ketoconazole shampoo significantly reduces scaling, itching, and erythema, with 2% outperforming 1% — a first-line, guideline-endorsed treatment.

Fungal skin infections

strong evidence

Creams treat tinea infections (ringworm, athlete's foot, pityriasis versicolor) with established efficacy.

Hair-loss adjunct

moderate evidence

Small studies suggest ketoconazole shampoo modestly supports hair density when added to minoxidil or finasteride regimens — an adjunct, not a standalone treatment.

Side effects & safety

Scalp dryness or irritation (uncommon)Usually mild; adjust frequency if it occurs.

Hair texture change (uncommon)Some users report dryness or coarseness with frequent use — condition afterward.

Safety considerations

Topical ketoconazole is generally considered low-risk in pregnancy; oral ketoconazole is avoided. Confirm with your provider.
Topical use has negligible systemic absorption and no meaningful drug interactions.
Not for: Known allergy to azole antifungals

How it's used

In skincare

Shampoo: use 1–2 times weekly for dandruff, lathering into the scalp and leaving 3–5 minutes before rinsing. For hair-loss adjunct use, typically 2–3 times weekly. Creams: apply once or twice daily to affected skin.

Regulatory status

OTC drug (1% shampoo) and prescription (2% shampoo, creams, foam). Oral ketoconazole is restricted due to liver risks.

Why the same shampoo treats dandruff and hair loss

Ketoconazole sits at an unusual crossroads: its antifungal action solves the Malassezia problem behind seborrheic dermatitis — and seborrheic dermatitis itself, by inflaming the follicle environment, contributes to hair shedding. But there is a second mechanism: ketoconazole locally inhibits androgen signaling at the follicle, complementing DHT-blocking treatments like finasteride. That dual action explains the clinical pattern — modest hair-density benefits in small studies when added to minoxidil or finasteride regimens, and the reasonable inference that part of the 'hair growth' seen with the shampoo is simply a healthier, inflammation-free scalp.

Frequently asked questions

How often should I use ketoconazole shampoo?

For dandruff, start at 2–3 times weekly, then drop to once weekly for maintenance once controlled. Leave it on the scalp 3–5 minutes before rinsing — contact time matters.

Can ketoconazole shampoo regrow hair?

On its own, only modestly at best. Its supported role is as an adjunct to minoxidil or finasteride, where small studies show added benefit — think of it as optimizing the scalp environment rather than growing hair.

Is ketoconazole shampoo safe long-term?

Yes — topical ketoconazole is minimally absorbed, and long-term intermittent use for seborrheic dermatitis is standard practice. The liver concerns apply to oral ketoconazole, not the shampoo.

The bottom line

Ketoconazole is the reference treatment for dandruff and seborrheic dermatitis — effective, guideline-endorsed, and safe as a topical — with a bonus role as a scalp-optimizing adjunct in hair-loss regimens. Use it 2–3 times weekly with proper contact time.

References

Ketoconazole for seborrheic dermatitis — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=ketoconazole+seborrheic+dermatitis+randomized
Ketoconazole shampoo and hair loss — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=ketoconazole+shampoo+hair+loss
Ketoconazole compound summary. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/compound/456201
Malassezia and seborrheic dermatitis (review). PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=Malassezia+seborrheic+dermatitis+review