Some research suggests that ketoconazole shampoo (sold in the U.S. under the brand name Nizoral) may be beneficial in men suffering from male pattern baldness. Anecdotal reports indicate that both the one-percent (available over-the-counter) and two-percent (available by prescription) dosages have hair loss benefits. The more potent 2% formulation may produce superior results.
Nizoral Shampoo is only FDA approved for the treatment of dandruff and seborrheic dermatitis of the scalp, so although Nizoral may be useful as a hair loss remedy, it cannot be endorsed or marketed as one to the general public.
One study, completed in 1998, compared ketoconazole shampoo (two-percent solution) to minoxidil two-percent in men with male pattern baldness.
The study concluded that “hair density and size and proportion of anagen follicles were improved almost similarly by both ketoconazole and minoxidil regimens”. Ketoconazole shampoo used two to four times a week was nearly as effective as the proven hair loss treatment minoxidil two-percent.
One other study, completed in 2005, corroborated the existence of a stimulatory effect on hair growth in mice. More rigorous studies on larger groups of men should be done to confirm the findings.
Mechanism of Action
While ketoconazole’s mechanism of action in hair loss is still unclear, it has been posited that ketoconazole effectively treats a fungus that commonly inhabits the scalp; researchers hypothesize that it may prevent hair loss by reducing inflammation from this fungus.
Excessive usage of either formulation has not been shown to produce better results. The results produced in the one study in men are based on ketoconazole 2% shampoo, used once every 2-4 days, and leaving the shampoo on the scalp for 3–5 minutes before rinsing (as with the treatment of dandruff).