Clascoterone is a topical drug that blocks male-type hormones at the hair follicle, slowing pattern hair loss while largely sparing the rest of the body. A stronger scalp solution showed measurable regrowth in men over six months, though evidence is early, maker-reported, and not yet approved. Side effects so far are mainly mild skin irritation. (Full Review)

Protocol

Dose

1.5 mL twice daily

5% solution to balding scalp (vertex and temples)

Application

Dry scalp, spaced across the day

Allow to dry before styling; no time-of-day advantage

Status

Investigational / off-label

5% scalp solution not yet approved for hair loss

Time to effect

Visible regrowth

~6 months

Primary trial endpoint; cosmetic change takes several months of consistent use

Early check

~3 months

Early tolerability and adherence reassessment

Maintenance

6-12 months

Continued use needed to judge and hold the gain

Benefits

Medium: Increased scalp hair count in male pattern hair loss

Low: Comparable or favorable local tolerability versus existing topicals; systemic-sparing androgen blockade

Speculative: Benefit in female pattern hair loss; additive effect when combined with minoxidil

Contraindications

Pregnancy or breastfeeding

Women of reproductive potential not using contraception

Hypersensitivity to clascoterone or the solution's components

Active scalp skin disease at the application site

Known adrenal insufficiency

Use under 18 for hair loss

Key Interactions

Potassium-raising drugs (ACE inhibitors such as lisinopril, angiotensin receptor blockers such as losartan, potassium-sparing diuretics such as spironolactone)

Other topical hair-loss agents (minoxidil, topical finasteride)

Antiandrogen "DHT blocker" supplements (saw palmetto, pumpkin seed oil)

Irritating OTC scalp products (strong exfoliants, high-alcohol tonics)

Risk & Side Effects

Medium: Local application-site reactions

Low: Theoretical suppression of the body's stress-hormone axis; local blood-chemistry shift seen with the acne formulation

Speculative: Systemic antiandrogen effects with overuse or broken skin; unknown long-term safety of the scalp solution

Monitoring

Marker	Target	Why
Target/Total Area Hair Count (TAHC)	Increase over baseline in the treated zone	Direct, objective measure of regrowth — the trial's primary endpoint
Serum potassium	~4.0-4.5 mmol/L (mid-normal)	Screens for the isolated hyperkalemia signal seen in controlled studies
Morning cortisol / ACTH-stimulation response	Normal adrenal response (no suppression)	Screens for the theoretical HPA-axis effect flagged in acne studies
Ferritin (iron stores)	~40-70 ng/mL	Low iron independently limits hair regrowth and can confound a poor response

Cadence: Reassess at ~3 months, at 6 months, then every 6-12 months; optional labs at baseline and repeated only if symptoms arise

Qualitative Assessment

Reduced daily shedding (fewer hairs on the pillow or in the shower)
Increased density or coverage at the part line, temples, and vertex on self-inspection
Improved hair caliber (thicker, more pigmented hairs replacing fine vellus hairs)
Scalp comfort and absence of persistent irritation, redness, or scaling

Clascoterone for Hair Regrowth

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment