Ketoconazole

• Pierard-Franchimont 1998 was a controlled comparison in androgenetic alopecia. A 2 percent ketoconazole shampoo was compared with an unmedicated shampoo used with or without 2 percent minoxidil. Hair density, hair size and the proportion of growing-phase (anagen) follicles improved almost equally with the ketoconazole and minoxidil regimens, and casual sebum levels appeared lower with ketoconazole; the authors called for a larger controlled study. The abstract does not give the number or sex of the participants (PMID: 9669136).
• Pierard-Franchimont 2002 was a randomized 6-month trial in 150 men with telogen effluvium linked to androgenetic alopecia and dandruff. Men used a 1 percent ketoconazole, 1 percent piroctone olamine or 1 percent zinc pyrithione shampoo. Hair density did not change; with ketoconazole, hair shedding fell 17.3 percent, the anagen hair percentage rose 4.9 percent and the mean hair shaft diameter rose 5.4 percent (PMID: 18498517).
• Khandpur 2002 was an open randomized trial in 100 men over 1 year. Groups received finasteride alone, finasteride plus 2 percent minoxidil, minoxidil alone, or finasteride plus 2 percent ketoconazole shampoo (10 men). Finasteride plus minoxidil scored best, followed by finasteride plus ketoconazole, and all finasteride groups did better than minoxidil alone (PMID: 12227482); see BodyHackGuide's finasteride and minoxidil guides.
• The Fields 2020 systematic review included five human studies with 318 participants and two animal studies; the human studies reported thicker hair shafts and clinical improvement, and the authors called for randomized controlled trials (PMID: 31858672).
• A ClinicalTrials.gov registry search on 27 October 2026 for alopecia or hair loss with ketoconazole as the intervention found no registered trials.

Hair loss: animal studies

• In C3H/HeN mice at Juntendo University in Tokyo (Jiang 2005), 2 percent ketoconazole in ethanol applied daily for 3 weeks regrew more of the clipped coat than vehicle (p<0.01, 10 mice) (PMID: 15863844).
• In male mice (Aldhalimi 2014), 2 percent ketoconazole, 5 percent minoxidil and minoxidil with tretinoin all regrew more hair than ethanol control, and minoxidil was the most effective (PMID: 24734193).

Guidelines and consensus statements

Japan's 2017 hair-loss guideline evaluated topical ketoconazole among several topical agents (PMID: 29863806). A 2025 Canadian Delphi consensus of 11 physicians, with four coauthors from a cosmetics company, listed ketoconazole shampoo among five interventions recommended with near consensus for androgenetic alopecia (PMID: 40986632).

Dandruff and seborrheic dermatitis

• The Okokon 2015 Cochrane review included 51 studies with 9,052 participants. In 8 trials against placebo, topical ketoconazole 2 percent gave a 31 percent lower risk of failed clearance of seborrheic dermatitis at 4 weeks (risk ratio 0.69), with low-quality evidence; ketoconazole matched steroids for remission with 44 percent fewer side effects (PMID: 25933684).
• Peter 1995 was a multicenter study of 575 patients with scalp seborrheic dermatitis and dandruff. After 2 to 4 weeks of 2 percent shampoo, 88 percent had an excellent response; in the 6-month preventive phase, relapse occurred in 47 percent on placebo against 19 percent on weekly ketoconazole shampoo (PMID: 7718463).
• In Danby 1993, a randomized, double-blind, placebo-controlled trial in 246 patients with moderate to severe dandruff, ketoconazole 2 percent and selenium sulfide 2.5 percent shampoos both beat placebo, and ketoconazole was better than selenium sulfide only at day 8 (PMID: 8245236).

Oral ketoconazole: the evidence behind the 2013 restrictions

• Lewis 1984 described 33 likely cases of liver injury from FDA reports. Most occurred in women over 40, jaundice appeared after 11 to 168 days of treatment, and one death seemed attributable to ketoconazole (PMID: 6319220).
• In a UK cohort of 69,830 oral antifungal users (Garcia Rodriguez 1999), ketoconazole carried the highest risk of acute liver injury of the drugs studied (PMID: 10594489).
• According to the Greenblatt 2014 review, the FDA and the EMA issued warnings or prohibitions on oral ketoconazole in 2013 because of liver injury that may lead to transplantation or death, although the true incidence is hard to determine from published data (PMID: 25216238).
• The Outeiro 2016 review found that in published drug interaction studies with 2,355 participants and a median of 6 days of ketoconazole, 40 (1.7 percent) had raised liver enzymes and none died, against 5.6 percent with raised liver enzymes in treatment studies with a median of 276 days (PMID: 27406945).

Oral ketoconazole in Cushing's disease

• Castinetti 2014 was a French retrospective multicenter study of 200 patients. At last follow-up, 49.3 percent had normal urinary free cortisol, 20.5 percent stopped for poor tolerance, and liver enzymes rose to less than 5 times normal in 13.5 percent and above 5 times normal in 2.5 percent, with no fatal hepatitis (PMID: 24471573).

Oral tablets: liver injury

The tablet label's boxed warning states that serious liver injury (including deaths and liver transplants) has occurred with oral ketoconazole, sometimes in patients without obvious risk factors, and its warnings section adds that this happened both with high doses over short periods and with low doses over long periods (US prescribing information for ketoconazole tablets). In an analysis of 54 reports of liver injury submitted to the FDA, 33 of them judged likely to be caused by ketoconazole, the authors put symptomatic, potentially serious liver injury at perhaps 1 in 15,000 exposed people and reported a published estimate of 5 to 10 percent for mild, reversible liver enzyme rises (PMID: 6319220). In a UK cohort of 69,830 users of oral antifungals, acute liver injury occurred at 134.1 per 100,000 person-months of ketoconazole use, based on 2 cases, a relative risk of 228 against nonusers (PMID: 10594489). A 2013 meta-analysis of 204 studies put the incidence of ketoconazole-related liver toxicity at 3.6 to 4.2 percent (PMID: 23895707). The EMA's 2013 review found that liver injury with oral ketoconazole was more frequent and more serious than with other antifungals and could start soon after treatment began at recommended doses (EMA referral on ketoconazole-containing medicines).

Oral tablets: hormones and adrenal glands

Pont and colleagues proposed that breast enlargement in men taking ketoconazole comes from a rise in the ratio of estradiol to testosterone, after 600 mg doses lowered testosterone much more than estradiol in four volunteers (PMID: 4040740). The tablet label lists breast enlargement and menstrual disorders among trial reactions and adrenocortical insufficiency, erectile dysfunction and, above recommended doses, absent sperm (azoospermia) among reports after approval (US prescribing information for ketoconazole tablets). In a trial of 350 men with metastatic prostate cancer given 1,200 mg a day, 11 died within two weeks of starting, and the label states that it could not be determined whether these deaths were caused by ketoconazole or adrenal insufficiency (US prescribing information for ketoconazole tablets).

Oral tablets: heart rhythm and other effects

At 200 mg twice a day for 3 to 7 days, ketoconazole raised the QTc interval by a mean maximum of about 6 to 12 milliseconds, and combining it with certain drugs can cause life-threatening rhythm problems such as torsades de pointes (US prescribing information for ketoconazole tablets). Other reported reactions include anaphylaxis after the first dose, nausea and vomiting, abdominal pain, headache, acute generalized exanthematous pustulosis and photosensitivity (US prescribing information for ketoconazole tablets).