Diphenylcyclopropenone (diphencyprone) is a topically administered drug intended for treating alopecia areata

Alopecia areata

Alopecia areata is a medical condition in which hair is lost from some or all areas of the body, usually from the scalp. Because it causes bald spots on the scalp, especially in the first stages, it is sometimes called spot baldness. In 1–2% of cases, the condition can spread to the entire scalp ...

 and alopecia totalis

Alopecia totalis

Alopecia totalis is the loss of all head hair. Its causes are unclear, but it is currently believed to be an autoimmune disorder. Stress is sometimes thought to be a contributor in alopecia areata...

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Mechanism of action

Diphenylcyclopropenone is believed to act as a local irritant, triggering a local sensitization. Thereby, it is thought to trigger an immune response that opposes the action of the autoreactive cells that otherwise are believed to cause hair loss.

Efficacy

A study of 41 patient showed a significant hair regrowth in 40% at 6 months, being sustained in two thirds of these after a 12-month-follow up-period.