Safety · 6 min read

Clascoterone side effects (hair-loss context)

The open question men ask is sexual side effects. The events trials actually logged look like topical dermatitis.

What the hair trials reported

Across SCALP 1 and 2, Cosmo said treatment-emergent adverse events were similar to vehicle and mostly unrelated to study drug. The 12-month update repeated vehicle-like chronic safety and no significant systemic endocrine effects, consistent with low systemic absorption.

That is the best signal we have. It is still sponsor topline until peer review.

Local reactions

Expect the usual topical-solution list: redness, itch, dryness, irritation, occasional contact dermatitis. Phase 2 notes described local skin reactions as mostly minimal or mild and fading with time. A twice-daily alcohol-containing solution will bother some scalps. Vehicle matters as much as molecule.

Systemic and sexual side effects

This is why the drug exists commercially. Investigators and company statements have emphasised no sexual-side-effect signal of the kind associated with oral 5-ARIs. “Not seen in this programme” is not “impossible in the wild.” Post-marketing is where rare events show up.

Clues from the Winlevi acne label

The approved 1% cream lists local irritation and, in some patients, HPA-axis effects when used over large areas — a known topical-steroid-adjacent caution even though clascoterone is not a classic glucocorticoid drug in use. Hair application on scalp is a different surface area and a different strength. Read the eventual AGA label rather than importing the acne label wholesale.

None of this is personalised medical advice. If you are already on finasteride or oral minoxidil, a clinician should own the combination decision.