Clascoterone is a topical hormone-blocking drug, sold as an acne cream, with a stronger scalp solution in development for pattern hair loss. In men with early to moderate thinning, developer-funded trials point to more scalp hair, fading after stopping; hair-number gains are unpublished. Women showed no overall benefit. Side effects reported so far are mostly mild scalp irritation; open concerns are temporary stress-hormone dampening and harm to a developing fetus. (Full Review)

Protocol

Phase 3 regimen

5% solution, about 1.5 mL twice daily

By dropper to the balding crown and temples

Time of day

Morning and evening

Applied to a dry scalp, without washing for several hours afterward

Dose-ranging alternative

7.5% twice daily

Largest hair-count change in phase 2; once daily gained fewer hairs

Time to effect

Continued gains

Through month 12

Hair count kept rising with steady use; partly lost after switching to drug-free solution

Main readout

Month 6

Main hair-count assessment in phase 3

First gains

From month 3

In phase 3, hair-count gains appeared from this point

Benefits

Medium: Increased scalp hair count in pattern hair loss; reduction in acne lesions

Speculative: Added regrowth when combined with minoxidil or finasteride

Contraindications

Pregnancy (contraception during use and for at least 10 days after stopping)

Breastfeeding (theoretical)

Children under 12; people under 18 for hair loss

Cuts, abrasions, eczema or sunburn on the scalp

Active seborrheic dermatitis, psoriasis or scalp infection

Adrenal insufficiency or long-term glucocorticoids (theoretical)

Known hypersensitivity to clascoterone or its inactive ingredients

Key Interactions

Glucocorticoids (prednisone, dexamethasone, clobetasol; theoretical)

Potassium-raising drugs (lisinopril, losartan, spironolactone, eplerenone, trimethoprim; theoretical)

5-alpha-reductase inhibitors and oral antiandrogens (finasteride, dutasteride, spironolactone, bicalutamide; theoretical)

Topical minoxidil (theoretical)

Hydrocortisone creams (extensive or prolonged use; theoretical)

Medicated or abrasive cleansers; ketoconazole shampoo (theoretical)

NSAIDs (ibuprofen, naproxen; regular use in kidney impairment; theoretical)

Potassium supplements and salt substitutes (potassium chloride; kidney impairment; theoretical)

Saw palmetto, pumpkin seed oil and other "DHT-blocking" supplements (theoretical)

Microneedling, lasers and other scalp procedures (theoretical)

Occlusive headwear and wigs

Risk & Side Effects

Low: Adrenal suppression; elevated blood potassium; local scalp irritation; stretch marks and skin thinning; menstrual and ovarian changes in women; acne flares and rash around the mouth; abnormal hair growth

Speculative: Body-wide androgen-blocking effects; harm to a developing fetus; heart rhythm effects

Monitoring

Marker	Target	Why
Target-area hair count / standardized scalp photographs	No established target; track change from own baseline	Expected to change: efficacy
Serum potassium	3.5–5.0 mmol/L	Safety check: elevated blood potassium
Morning serum cortisol	About 5–23 µg/dL at 8 a.m. (varies by laboratory)	Safety check: adrenal suppression
Pregnancy test (women who could become pregnant)	Negative before starting	Safety check: fetal harm

Cadence: Baseline, 3 months, 6 months, then every 6–12 months for photographs; potassium and morning cortisol in higher-risk groups at baseline, 3 months, then yearly, or promptly if fatigue, dizziness or weakness appear

Qualitative Assessment

Visible density and scalp show-through in consistent photographs
Shedding volume (brief early shedding versus persistent loss)
Scalp itching, redness, scaling or burning
Sexual function, libido and breast tenderness
Menstrual regularity (women)
Fatigue, dizziness or weakness suggesting adrenal effects
Overall satisfaction with hair appearance

Clascoterone for Hair Regrowth

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment