Ketoconazole shampoo for hair loss

What it is

Ketoconazole kills or slows down yeasts and fungi. On the scalp, the main target is a yeast called Malassezia, which lives on everyone's skin and plays a part in dandruff and seborrhoeic dermatitis, the red, flaky, sometimes itchy scalp condition.

Ketoconazole shampoo comes in two common strengths. The 2% shampoo is a medicine and is the strength used in hair studies. Weaker 1% shampoos are also sold. Rules on which strength you can buy without a prescription differ between countries, so ask a pharmacist.

Why people use it for hair loss

There are two ideas behind it.

The first is that a calmer scalp is a better place for hair to grow. Inflammation around the follicles, from dandruff or seborrhoeic dermatitis, may add to thinning in some people. Treating it removes that extra stress.

The second is that ketoconazole may have a mild anti-androgen effect in the skin, weakening the action of DHT, the hormone behind pattern hair loss. This comes mostly from laboratory and animal work, and it has not been shown clearly in people.

What the studies show

The evidence is small and old.

An often-cited study from 1998 compared ketoconazole 2% shampoo with an ordinary shampoo, with and without minoxidil 2%.¹ The authors reported that hair density, hair size and the share of growing hairs improved almost as much with ketoconazole as with minoxidil, and that ketoconazole seemed to reduce oiliness. They also wrote that a larger controlled study was needed to show whether this matters in practice. We could not check the number of people or the exact figures, which were not in the summary we read.

A 2020 systematic review found only five studies in people, with 318 participants in total, plus two animal studies.² The human studies suggested thicker hair shafts and some improvement in photos and in how people rated their hair. The authors called ketoconazole a promising add-on or alternative, but said proper randomised trials were still needed.

The 2017 European guideline on pattern hair loss lists ketoconazole among treatments with too little evidence for a recommendation, for or against.³

Where it fits

Put plainly: ketoconazole shampoo is not a proven hair-loss treatment, but it is cheap, widely available, and safe for most people. That makes it a common third step after minoxidil and, for men, finasteride.

It makes the most sense if you also have dandruff, a flaky or itchy scalp, or seborrhoeic dermatitis. In that case, you are treating a real scalp problem, and any help for your hair is a bonus.

It does not replace minoxidil or finasteride. If you only change your shampoo, do not expect your hair loss to stop.

How to use it

Follow the leaflet for your product. A common routine for hair is:

Use it two or three times a week, in place of your usual shampoo.
Lather it into the scalp, not just the hair.
Leave it on for three to five minutes before rinsing. The contact time matters more than the amount of foam.
On other days, use a mild shampoo.

If you use topical minoxidil, wash and dry your scalp first, then apply minoxidil. See how to use minoxidil.

Side effects

Ketoconazole shampoo is usually well tolerated. Possible side effects include:

dryness, itching or irritation of the scalp
hair that feels dry or brittle
changes in hair texture, and rarely colour, especially in grey or chemically treated hair

Keep it out of your eyes. Stop using it if your scalp becomes red and sore, and see a pharmacist or doctor. If you have a scalp rash that does not settle with an anti-dandruff shampoo, get it checked: it could be something else.