--- title: "Ketoconazole: Research & Side Effects | BodyHackGuide" url: https://www.bodyhackguide.co/compound/ketoconazole description: "Ketoconazole: mechanism, clinical studies & side effects." lang: en --- Skip to content Compare notes on r/BodyHackGuide (https://reddit.com/r/bodyhackguide) Compare notes with other researchers. Join r/BodyHackGuide (https://reddit.com/r/bodyhackguide) # Ketoconazole Skin & Hair: https://www.bodyhackguide.co/wiki#cat-skin-&-hair Status Approved (prescription and over the counter) Evidence Not graded on a research bench yet Ketoconazole is a synthetic imidazole antifungal that blocks the fungal cytochrome P450 enzyme lanosterol 14-alpha-demethylase and so stops the yeast or mold from making ergosterol for its cell membrane; it was the first broad-spectrum oral antifungal approved by the FDA, as Nizoral tablets from Janssen in 1981, and is also sold as 2 percent and 1 percent shampoos, creams and foams. Reviewed 4 November 2026 01 Overview ## What Ketoconazole is In hair-loss routines ketoconazole is used as a shampoo, and the human hair data come from small studies, two of them from a group in Liege, Belgium, that measured hair shedding, shaft thickness and growing-phase hairs; a 2020 systematic review called for randomized controlled trials (PMID: 9669136, PMID: 18498517, PMID: 31858672). Oral ketoconazole is regulated very differently: in July 2013 the FDA restricted the tablets to serious systemic fungal infections, revised their boxed warning on liver injury, QT prolongation and drug interactions, and added a warning on adrenal insufficiency, and the European Union suspended oral ketoconazole for fungal infections the same year (FDA supplement approval letter, NDA 018533/S-040; EMA referral on ketoconazole-containing medicines). Ketoconazole was not detected in plasma in label studies of long-term shampoo use, and the European Medicines Agency kept topical forms on the market because so little is absorbed (US prescribing information for ketoconazole 2% shampoo; EMA referral on ketoconazole-containing medicines). ### How it works ### Antifungal action Ketoconazole blocks the synthesis of ergosterol, a building block of the fungal cell membrane, by inhibiting the cytochrome P450 enzyme lanosterol 14-alpha-demethylase; methylated sterol precursors build up and the membrane is weakened (US prescribing information for ketoconazole tablets). For the 2 percent shampoo, the US label states that its effect on dandruff is thought, though not proven, to come from reducing the scalp yeast Pityrosporum ovale (US prescribing information for ketoconazole 2% shampoo). Read the full mechanism Show less ### Proposed actions on hair The Liege dermatopathology group behind the 1998 shampoo study proposed that an inflammatory reaction driven by scalp microbes around the follicles may contribute to androgenetic alopecia, and that ketoconazole's activity against the scalp microflora (including Malassezia yeasts) and its anti-inflammatory activity might help; they also reported lower casual sebum levels with the shampoo (PMID: 9669136). A 2026 review of the scalp microbiome in androgenetic alopecia found that increases in the bacterium Cutibacterium acnes were the most consistent finding, while increases in Malassezia yeasts were reported less consistently (PMID: 41823643). In laboratory tests on cultured human skin cells, ketoconazole competed with androgens for the androgen receptor, but half the receptors were displaced only at about 64 micromolar, a level the author judged unlikely to be reached in plasma (PMID: 1526623). ### Steroid synthesis with oral doses Taken by mouth, ketoconazole also blocks human steroid-making enzymes. In volunteers, single oral doses of 200 to 600 mg lowered serum testosterone markedly, with recovery toward baseline 8 to 24 hours later (PMID: 6291475), and 400 or 600 mg doses blunted the cortisol response to ACTH for up to 8 hours (PMID: 6287893). At 800 to 1,200 mg a day, the blockade lasted longer, with low testosterone, low or absent sperm counts, impotence and breast enlargement (PMID: 6093722). In men with prostate cancer on long-term high doses, the main site of action appeared to be 17,20-lyase (17-20 desmolase), with a possible moderate blockade of 17-hydroxylase and marked blockade of 21- or 11-hydroxylase (PMID: 2966691). The current tablet label states that ketoconazole decreases adrenal corticosteroid secretion at doses of 400 mg and higher and lowers serum testosterone, which is impaired at 800 mg a day and abolished at 1,600 mg a day (US prescribing information for ketoconazole tablets). ### Drug interactions Ketoconazole is a potent inhibitor of the drug-metabolizing enzyme CYP3A4 and of the drug transporter P-glycoprotein (US prescribing information for ketoconazole tablets), and it has been used extensively as the index CYP3A inhibitor in drug interaction studies (PMID: 27406945, PMID: 25216238). ### Absorption from shampoo Ketoconazole was not detected in plasma in 39 patients who shampooed 4 to 10 times a week for 6 months, or in 33 patients who shampooed 2 to 3 times a week for 3 to 26 months (US prescribing information for ketoconazole 2% shampoo). When the European Union suspended oral ketoconazole in 2013, topical creams, ointments and shampoos stayed on the market because very little ketoconazole is absorbed from them (EMA referral on ketoconazole-containing medicines). ### Two mirror-image forms Ketoconazole is a racemic mixture of two cis enantiomers; one of them, levoketoconazole (the 2S,4R form), was approved by the FDA on 30 December 2021 as a separate drug for high cortisol in Cushing's syndrome and is not approved for fungal infections (Drugs@FDA NDA 214133; US prescribing information for levoketoconazole). ### Studied for - Seborrheic dermatitis and dandruff - Androgenetic alopecia - Antifungal pharmacology - Drug-induced liver injury - Steroidogenesis inhibition - CYP3A4 drug interactions - Cushing's syndrome ### Benefits listed - Hair shedding, the percentage of growing-phase hairs and hair shaft diameter with a 1 percent shampoo over 6 months, in one of three shampoo groups in a 150-man trial with no unmedicated comparison (PMID: 18498517) - Hair density, hair size and growing-phase follicles with a 2 percent shampoo in a small controlled comparison with minoxidil (PMID: 9669136) - Hair regrowth on clipped skin in mice (PMID: 15863844) - Clearance of seborrheic dermatitis against placebo, with a 31 percent lower risk of failed clearance across 8 trials (PMID: 25933684) Show 2 more Show less - Dandruff relapse during 6 months of preventive use in 312 patients (PMID: 7718463) - Urinary free cortisol in 200 patients with Cushing's disease given oral ketoconazole (PMID: 24471573) 02 Research Free with email ## What the research shows No research bench grades Ketoconazole yet. Benches compare compounds people pair, with the evidence for each. ### Unlock the research summary Enter your email to keep reading. It is free, and it opens these sections on every compound page in this browser. - A summary of the key research - Safety and side effects - A link to the PubMed results You also get the free peptide cheat sheet by email. Unsubscribe anytime. Have an account? Sign in (https://www.bodyhackguide.co/auth) 03 Safety ## Ketoconazole side effects and interactions ### Side effects #### Common - Increase in normal hair loss and irritation in fewer than 1 percent of 264 patients in 11 double-blind shampoo trials (US prescribing information for ketoconazole 2% shampoo) - Itching, dry skin, application site reactions, hair discoloration and abnormal hair texture with the shampoo (US prescribing information for ketoconazole 2% shampoo) - Nausea and vomiting, abdominal pain and headache with oral tablets (US prescribing information for ketoconazole tablets) - Mild, reversible liver enzyme rises in an estimated 5 to 10 percent of oral users (PMID: 6319220) #### Serious events - Serious liver injury (including deaths and liver transplants) with oral tablets (US prescribing information for ketoconazole tablets) - Acute liver injury at 134.1 per 100,000 person-months of oral use in a UK cohort (PMID: 10594489) - Lower adrenal corticosteroid output at oral doses of 400 mg or more, and adrenocortical insufficiency reported after approval (US prescribing information for ketoconazole tablets) - QT prolongation and torsades de pointes with interacting drugs (US prescribing information for ketoconazole tablets) - Anaphylaxis, reported with both tablets and shampoo (US prescribing information for ketoconazole tablets and 2% shampoo) ### Who should not use it Contraindications The tablet label contraindicates oral ketoconazole in acute or chronic liver disease, and it advises against alcohol and, where possible, other drugs that can harm the liver during treatment (US prescribing information for ketoconazole tablets). Read all the contraindications and cautions Show less Combining the tablets with any of these drugs is contraindicated on the label: dofetilide, quinidine, pimozide, lurasidone, cisapride, methadone, disopyramide, dronedarone, ranolazine, ergot alkaloids, irinotecan, oral midazolam, alprazolam, triazolam, felodipine, nisoldipine, tolvaptan, eplerenone, lovastatin, simvastatin and colchicine (US prescribing information for ketoconazole tablets). The tablet label warns that ketoconazole lowers adrenal corticosteroid output at doses of 400 mg or more and calls for adrenal monitoring in people with adrenal insufficiency, borderline adrenal function or prolonged stress such as major surgery (US prescribing information for ketoconazole tablets). The tablet label reports liver toxicity (including deaths and liver transplants) in patients given oral ketoconazole for unapproved uses: nail fungus, skin dermatophyte infections or Candida infections, which the tablets are not indicated to treat (US prescribing information for ketoconazole tablets). As for pregnancy, oral ketoconazole caused limb malformations (syndactylia and oligodactylia) in rats at 80 mg/kg a day, possibly related to maternal toxicity, while ketoconazole was not detected in plasma after long-term shampooing (US prescribing information for ketoconazole 2% shampoo). The 2 percent shampoo is contraindicated in people with known hypersensitivity to its ingredients, can irritate the eyes, and has been reported to remove the curl from permanently waved hair (US prescribing information for ketoconazole 2% shampoo). ### Interactions 5 pairings in our record: 2 to avoid, 2 with a caution and 1 to monitor. - CYP3A4-metabolized drugs (with oral ketoconazole) Avoid The tablet label contraindicates oral ketoconazole with many CYP3A4 substrates such as dofetilide, quinidine, pimozide, cisapride, methadone, ranolazine, lovastatin, simvastatin, oral midazolam and triazolam, because raised levels can cause QT prolongation, sedation or muscle injury (US prescribing information for ketoconazole tablets). - Alcohol (with oral ketoconazole) Avoid The tablet label advises against alcohol during oral ketoconazole treatment because of the risk of liver injury (US prescribing information for ketoconazole tablets). - Rifampicin, carbamazepine, phenytoin and other CYP3A4 inducers Caution Potent CYP3A4 inducers such as rifampicin, isoniazid, carbamazepine, phenytoin, efavirenz and nevirapine can lower oral ketoconazole levels enough to reduce efficacy, and the label does not recommend these combinations (US prescribing information for ketoconazole tablets). - Dutasteride Caution In rats, ketoconazole given at the same time as dutasteride significantly changed the pharmacokinetics of dutasteride and its active metabolite (PMID: 31835695), and the dutasteride label lists ketoconazole among CYP3A4 inhibitors that may raise dutasteride levels (US prescribing information for Avodart). - Proton pump inhibitors, H2 blockers and antacids Monitor Acid-reducing drugs impair absorption of oral ketoconazole: after omeprazole, the bioavailability of a fasting dose fell to 17 percent of normal (US prescribing information for ketoconazole tablets). This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds. Need bloodwork before starting? Full hormone + metabolic panels from Anabolic Insights. Code CHONCH for first-order discount. Order Bloodwork (https://anabolicinsights.ai/?ref=nwm2zjb) 04 Dosing Free with email ## Dosing No dose on record Our record lists no dose for Ketoconazole. This section holds what it does list. ### Unlock the Dosing section - Route 05 Prices ## Ketoconazole prices No listings We do not track a vendor for Ketoconazole yet, so this page states no price. 06 Chemistry ## Chemistry and structure Molecular formula C26H28Cl2N4O4 Molecular mass 531.4 g/mol CAS number 65277-42-1 Half-life Oral tablets: elimination from plasma is biphasic, with a half-life of about 2 hours over the first 10 hours and about 8 hours after that (US prescribing information for ketoconazole tablets). Shampoo: ketoconazole was not detected in plasma after long-term shampooing, so no topical half-life has been measured (US prescribing information for ketoconazole 2% shampoo). View on PubChem (https://pubchem.ncbi.nlm.nih.gov/compound/47576) 07 Related ## Related to Ketoconazole ### In the same category - Acetyl Hexapeptide-8Marketed topical cosmetic ingredient Acetyl Hexapeptide-8 (INCI: Acetyl Hexapeptide-3 in older nomenclature, commercially known as Argireline) is a synthetic hexapeptide designed as a competitive inhibitor of the SNARE complex at the neuromuscular junction.: https://www.bodyhackguide.co/compound/acetyl-hexapeptide-8 - AHK-CuPreclinical AHK-Cu is a copper chelating tripeptide related to but distinct from GHK-Cu.: https://www.bodyhackguide.co/compound/ahk-cu - DutasteridePhase 3 Dutasteride is a synthetic 4-azasteroid drug that blocks both type 1 and type 2 steroid 5-alpha-reductase, the enzymes that turn testosterone into dihydrotestosterone (DHT); it was developed at Glaxo Wellcome under the code GG745 and approved by the FDA in 2001 as Avodart for benign prostatic hyperplasia.: https://www.bodyhackguide.co/compound/dutasteride - Melanotan 2Discontinued A synthetic melanocortin receptor agonist studied for skin tanning, sexual function, and appetite suppression.: https://www.bodyhackguide.co/compound/melanotan-2 - MinoxidilFDA-Approved Minoxidil is an FDA-approved treatment for pattern hair loss. Originally an oral blood-pressure drug, its hair-growth side effect led to the topical products (Rogaine) at 2% and 5%.: https://www.bodyhackguide.co/compound/minoxidil - Palmitoyl Pentapeptide-4Marketed topical cosmetic ingredient with a small set of human cosmetic trials Palmitoyl pentapeptide-4 is the cosmetic ingredient Pal-KTTKS, a five-amino-acid fragment of the type I collagen propeptide with a 16-carbon palmitic acid chain attached, sold to formulators under the trade name Matrixyl (PubChem CID 9897237; PMID: 8486721).: https://www.bodyhackguide.co/compound/palmitoyl-pentapeptide-4 All compounds (https://www.bodyhackguide.co/wiki) ### Compare Ketoconazole - Alternatives to Ketoconazole: https://www.bodyhackguide.co/alternatives-to/ketoconazole ### Research tools - Peptide Calculator Reconstitution and syringe units: https://www.bodyhackguide.co/tools/reconstitution - Reconstitution Guide How to mix, step by step: https://www.bodyhackguide.co/guides/how-to-reconstitute-peptides - Nasal Spray Calc mL per actuation: https://www.bodyhackguide.co/tools/intranasal - Half-Life Visualizer Decay curves: https://www.bodyhackguide.co/tools/halflife All articles (https://www.bodyhackguide.co/blog) 08 Questions ## Frequently asked questions What is ketoconazole? Ketoconazole is a synthetic imidazole antifungal that blocks ergosterol synthesis in the fungal cell membrane (US prescribing information for ketoconazole tablets; PMID: 15863844). Ketoconazole was the first broad-spectrum oral antifungal approved by the FDA, in 1981 (PMID: 25409549). Ketoconazole is also sold in the US as 2 percent and 1 percent shampoos, creams and foams, while the only ketoconazole gel approved in the US, Xolegel, is discontinued (Drugs@FDA). Does ketoconazole shampoo help with hair loss? In a 6-month trial in 150 men with hair shedding and dandruff, split among three antidandruff shampoos with no unmedicated comparison, hair shedding fell 17.3 percent and hair shafts thickened 5.4 percent in the group using 1 percent ketoconazole shampoo, a piroctone olamine shampoo gave similar results, and hair density did not change (PMID: 18498517). A small controlled study found that 2 percent ketoconazole shampoo improved hair density and growing-phase hairs about as much as 2 percent minoxidil (PMID: 9669136). A 2020 systematic review of ketoconazole for androgenetic alopecia found 5 small human studies and called for randomized controlled trials (PMID: 31858672). Is ketoconazole approved for hair loss? No ketoconazole product is FDA approved for hair loss (Drugs@FDA product labels). US labels indicate ketoconazole 2 percent shampoo for tinea versicolor, and ketoconazole 1 percent shampoo is sold over the counter to control dandruff (US prescribing information for ketoconazole 2% shampoo; Drugs@FDA NDA 020310). A 2025 Canadian consensus listed ketoconazole shampoo among interventions recommended with near consensus for androgenetic alopecia (PMID: 40986632). Why did the FDA restrict oral ketoconazole in 2013? In July 2013 the FDA advised against oral ketoconazole as a first-line treatment for any fungal infection because of liver injury, adrenal gland problems and serious drug interactions (PMID: 27406945). The 2013 ketoconazole tablet label revised the boxed warning on liver injury, QT prolongation and drug interactions and limited the tablets to serious systemic fungal infections (FDA supplement approval letter, NDA 018533/S-040). In a UK cohort, acute liver injury occurred at 134.1 per 100,000 person-months of ketoconazole use (PMID: 10594489). Is ketoconazole shampoo absorbed into the body? Ketoconazole was not detected in plasma in 39 patients who used ketoconazole 2 percent shampoo 4 to 10 times a week for 6 months (US prescribing information for ketoconazole 2% shampoo). The European Medicines Agency kept topical ketoconazole on the market in 2013 because very little ketoconazole is absorbed from creams, ointments and shampoos (EMA referral on ketoconazole-containing medicines). What side effects were reported with ketoconazole shampoo? In 11 trials with 264 patients using ketoconazole 2 percent shampoo, an increase in normal hair loss and irritation occurred in fewer than 1 percent (US prescribing information for ketoconazole 2% shampoo). Reports after marketing of ketoconazole shampoo include hair discoloration, abnormal hair texture, loss of curl in permanently waved hair, contact dermatitis and anaphylaxis (US prescribing information for ketoconazole 2% shampoo). Does ketoconazole block androgens? Oral ketoconazole at 200 to 600 mg lowered serum testosterone for several hours in volunteers (PMID: 6291475), and ketoconazole at 800 to 1,200 mg a day caused longer-lasting testosterone suppression (PMID: 6093722). In cultured human skin cells, ketoconazole bound the androgen receptor only at concentrations the author judged unlikely in plasma (PMID: 1526623). A PubMed search on 27 October 2026 found no study that measured hormone levels during ketoconazole shampoo use, and ketoconazole was not detected in plasma after long-term shampooing (US prescribing information for ketoconazole 2% shampoo). Free 2026 Peptide Cheat Sheet (PDF) 38 compounds and blends: vial sizes, BAC water volumes, dosing ranges and bloodwork markers. Download Free (https://www.bodyhackguide.co/guides/peptide-cheat-sheet-download) BodyHackGuide (https://www.bodyhackguide.co/) Your biohacking research hub: compound pricing, brain health protocols, dosing tools, and vendor reviews. support@bodyhackguide.co Join our Discord: https://discord.gg/Mhq5UdRYBA r/BodyHackGuide on Reddit: https://reddit.com/r/BodyHackGuide **Affiliate Disclosure:** We rank every vendor on the same public, reproducible methodology (https://www.bodyhackguide.co/vendors/methodology). 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All rights reserved. - Terms: https://www.bodyhackguide.co/terms - Privacy: https://www.bodyhackguide.co/privacy ## Structured data ```json [ { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://www.bodyhackguide.co/" }, { "@type": "ListItem", "position": 2, "name": "Compounds", "item": "https://www.bodyhackguide.co/compare" }, { "@type": "ListItem", "position": 3, "name": "Ketoconazole" } ] }, { "@context": "https://schema.org", "@type": "MedicalWebPage", "name": "Ketoconazole", "description": "Ketoconazole is a synthetic imidazole antifungal that blocks the fungal cytochrome P450 enzyme lanosterol 14-alpha-demethylase and so stops the yeast or mold from making ergosterol for its cell membrane; it was the first broad-spectrum oral antifungal approved by the FDA, as Nizoral tablets from Janssen in 1981, and is also sold as 2 percent and 1 percent shampoos, creams and foams (PMID: 25409549; Drugs@FDA NDA 018533; US prescribing information for ketoconazole tablets). In hair-loss routines ketoconazole is used as a shampoo, and the human hair data come from small studies, two of them from a group in Liege, Belgium, that measured hair shedding, shaft thickness and growing-phase hairs; a 2020 systematic review called for randomized controlled trials (PMID: 9669136, PMID: 18498517, PMID: 31858672). Oral ketoconazole is regulated very differently: in July 2013 the FDA restricted the tablets to serious systemic fungal infections, revised their boxed warning on liver injury, QT prolongation and drug interactions, and added a warning on adrenal insufficiency, and the European Union suspended oral ketoconazole for fungal infections the same year (FDA supplement approval letter, NDA 018533/S-040; EMA referral on ketoconazole-containing medicines). 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In hair-loss routines ketoconazole is used as a shampoo, and the human hair data come from small studies, two of them from a group in Liege, Belgium, that measured hair shedding, shaft thickness and growing-phase hairs; a 2020 systematic review called for randomized controlled trials (PMID: 9669136, PMID: 18498517, PMID: 31858672). Oral ketoconazole is regulated very differently: in July 2013 the FDA restricted the tablets to serious systemic fungal infections, revised their boxed warning on liver injury, QT prolongation and drug interactions, and added a warning on adrenal insufficiency, and the European Union suspended oral ketoconazole for fungal infections the same year (FDA supplement approval letter, NDA 018533/S-040; EMA referral on ketoconazole-containing medicines). Ketoconazole was not detected in plasma in label studies of long-term shampoo use, and the European Medicines Agency kept topical forms on the market because so little is absorbed (US prescribing information for ketoconazole 2% shampoo; EMA referral on ketoconazole-containing medicines).", "activeIngredient": "Ketoconazole", "administrationRoute": "Topical, Oral", "mechanismOfAction": "Antifungal action Ketoconazole blocks the synthesis of ergosterol, a building block of the fungal cell membrane, by inhibiting the cytochrome P450 enzyme lanosterol 14-alpha-demethylase; methylated sterol precursors build up and the membrane is weakened (US prescribing information for ketoconazole tablets). For the 2 percent shampoo, the US label states that its effect on dandruff is thought, though not proven, to come from reducing the scalp yeast Pityrosporum ovale (US prescribing information for ketoconazole 2% shampoo). Proposed actions on hair The Liege dermatopathology group behind the 1998 shampoo study proposed that an inflammatory reaction driven by scalp microbes around the follicles may contribute to androgenetic alopecia, and that ketoconazole's activity against the scalp microflora (including Malassezia yeasts) and its anti-inflammatory activity might help; they also reported lower casual sebum levels with the shampoo (PMID: 9669136). A 2026 review of the scalp microbiome in androgenetic alopecia found that increases in the bacterium Cutibacterium acnes were the most consistent finding, while increases in Malassezia yeasts were reported less consistently (PMID: 41823643). In laboratory tests on cultured human skin cells, ketoconazole competed with androgens for the androgen receptor, but half the receptors were displaced only at about 64 micromolar, a level the author judged unlikely to be reached in plasma (PMID: 1526623). Steroid synthesis with oral doses Taken by mouth, ketoconazole also blocks human steroid-making enzymes. In volunteers, single oral doses of 200 to 600 mg lowered serum testosterone markedly, with recovery toward baseline 8 to 24 hours later (PMID: 6291475), and 400 or 600 mg doses blunted the cortisol response to ACTH for up to 8 hours (PMID: 6287893). At 800 to 1,200 mg a day, the blockade lasted longer, with low testosterone, low or absent sperm counts, impotence and breast enlargement (PMID: 6093722). In men with prostate cancer on long-term high doses, the main site of action appeared to be 17,20-lyase (17-20 desmolase), with a possible moderate blockade of 17-hydroxylase and marked blockade of 21- or 11-hydroxylase (PMID: 2966691). The current tablet label states that ketoconazole decreases adrenal corticosteroid secretion at doses of 400 mg and higher and lowers serum testosterone, which is impaired at 800 mg a day and abolished at 1,600 mg a day (US prescribing information for ketoconazole tablets). Drug interactions Ketoconazole is a potent inhibitor of the drug-metabolizing enzyme CYP3A4 and of the drug transporter P-glycoprotein (US prescribing information for ketoconazole tablets), and it has been used extensively as the index CYP3A inhibitor in drug interaction studies (PMID: 27406945, PMID: 25216238). Absorption from shampoo Ketoconazole was not detected in plasma in 39 patients who shampooed 4 to 10 times a week for 6 months, or in 33 patients who shampooed 2 to 3 times a week for 3 to 26 months (US prescribing information for ketoconazole 2% shampoo). When the European Union suspended oral ketoconazole in 2013, topical creams, ointments and shampoos stayed on the market because very little ketoconazole is absorbed from them (EMA referral on ketoconazole-containing medicines). Two mirror-image forms Ketoconazole is a racemic mixture of two cis enantiomers; one of them, levoketoconazole (the 2S,4R form), was approved by the FDA on 30 December 2021 as a separate drug for high cortisol in Cushing's syndrome and is not approved for fungal infections (Drugs@FDA NDA 214133; US prescribing information for levoketoconazole).", "legalStatus": "Approved (prescription and over the counter)" } }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "What is ketoconazole?", "acceptedAnswer": { "@type": "Answer", "text": "Ketoconazole is a synthetic imidazole antifungal that blocks ergosterol synthesis in the fungal cell membrane (US prescribing information for ketoconazole tablets; PMID: 15863844). Ketoconazole was the first broad-spectrum oral antifungal approved by the FDA, in 1981 (PMID: 25409549). Ketoconazole is also sold in the US as 2 percent and 1 percent shampoos, creams and foams, while the only ketoconazole gel approved in the US, Xolegel, is discontinued (Drugs@FDA)." } }, { "@type": "Question", "name": "Does ketoconazole shampoo help with hair loss?", "acceptedAnswer": { "@type": "Answer", "text": "In a 6-month trial in 150 men with hair shedding and dandruff, split among three antidandruff shampoos with no unmedicated comparison, hair shedding fell 17.3 percent and hair shafts thickened 5.4 percent in the group using 1 percent ketoconazole shampoo, a piroctone olamine shampoo gave similar results, and hair density did not change (PMID: 18498517). A small controlled study found that 2 percent ketoconazole shampoo improved hair density and growing-phase hairs about as much as 2 percent minoxidil (PMID: 9669136). A 2020 systematic review of ketoconazole for androgenetic alopecia found 5 small human studies and called for randomized controlled trials (PMID: 31858672)." } }, { "@type": "Question", "name": "Is ketoconazole approved for hair loss?", "acceptedAnswer": { "@type": "Answer", "text": "No ketoconazole product is FDA approved for hair loss (Drugs@FDA product labels). US labels indicate ketoconazole 2 percent shampoo for tinea versicolor, and ketoconazole 1 percent shampoo is sold over the counter to control dandruff (US prescribing information for ketoconazole 2% shampoo; Drugs@FDA NDA 020310). A 2025 Canadian consensus listed ketoconazole shampoo among interventions recommended with near consensus for androgenetic alopecia (PMID: 40986632)." } }, { "@type": "Question", "name": "Why did the FDA restrict oral ketoconazole in 2013?", "acceptedAnswer": { "@type": "Answer", "text": "In July 2013 the FDA advised against oral ketoconazole as a first-line treatment for any fungal infection because of liver injury, adrenal gland problems and serious drug interactions (PMID: 27406945). The 2013 ketoconazole tablet label revised the boxed warning on liver injury, QT prolongation and drug interactions and limited the tablets to serious systemic fungal infections (FDA supplement approval letter, NDA 018533/S-040). In a UK cohort, acute liver injury occurred at 134.1 per 100,000 person-months of ketoconazole use (PMID: 10594489)." } }, { "@type": "Question", "name": "Is ketoconazole shampoo absorbed into the body?", "acceptedAnswer": { "@type": "Answer", "text": "Ketoconazole was not detected in plasma in 39 patients who used ketoconazole 2 percent shampoo 4 to 10 times a week for 6 months (US prescribing information for ketoconazole 2% shampoo). The European Medicines Agency kept topical ketoconazole on the market in 2013 because very little ketoconazole is absorbed from creams, ointments and shampoos (EMA referral on ketoconazole-containing medicines)." } }, { "@type": "Question", "name": "What side effects were reported with ketoconazole shampoo?", "acceptedAnswer": { "@type": "Answer", "text": "In 11 trials with 264 patients using ketoconazole 2 percent shampoo, an increase in normal hair loss and irritation occurred in fewer than 1 percent (US prescribing information for ketoconazole 2% shampoo). Reports after marketing of ketoconazole shampoo include hair discoloration, abnormal hair texture, loss of curl in permanently waved hair, contact dermatitis and anaphylaxis (US prescribing information for ketoconazole 2% shampoo)." } }, { "@type": "Question", "name": "Does ketoconazole block androgens?", "acceptedAnswer": { "@type": "Answer", "text": "Oral ketoconazole at 200 to 600 mg lowered serum testosterone for several hours in volunteers (PMID: 6291475), and ketoconazole at 800 to 1,200 mg a day caused longer-lasting testosterone suppression (PMID: 6093722). In cultured human skin cells, ketoconazole bound the androgen receptor only at concentrations the author judged unlikely in plasma (PMID: 1526623). A PubMed search on 27 October 2026 found no study that measured hormone levels during ketoconazole shampoo use, and ketoconazole was not detected in plasma after long-term shampooing (US prescribing information for ketoconazole 2% shampoo)." } } ] }, { "@context": "https://schema.org", "@type": "Organization", "@id": "https://www.bodyhackguide.co#organization", "name": "BodyHackGuide", "alternateName": "BHG", "url": "https://www.bodyhackguide.co", "logo": { "@type": "ImageObject", "url": "https://www.bodyhackguide.co/logo.png", "width": 512, "height": 512 }, "description": "Evidence-based research reference for peptides and nootropics. 273 compound profiles, interactive dosing calculators, vendor price comparisons, and trust-scored vendor reviews scored on a public, reproducible methodology applied to every vendor. We earn a commission on purchases through some of our links.", "foundingDate": "2024", "founder": { "@id": "https://www.bodyhackguide.co/about#person" }, "sameAs": [ "https://reddit.com/r/BodyHackGuide", "https://reddit.com/r/BrainHackGuide", "https://reddit.com/r/Biohackingher", "https://discord.gg/Mhq5UdRYBA" ], "knowsAbout": [ "Peptide research", "Nootropic research", "Biohacking", "Compound dosing", "Vendor transparency" ], "publishingPrinciples": "https://www.bodyhackguide.co/editorial-standards", "ethicsPolicy": "https://www.bodyhackguide.co/editorial-standards", "diversityPolicy": "https://www.bodyhackguide.co/editorial-standards" } ] ```