Bimatoprost, sold under the brand name Lumigan among others, is a medication used to treat high pressure inside the eye including glaucoma.

[8][9] Bimatoprost is used for the treatment of open-angle glaucoma and ocular hypertension in adults, either alone or in combination with a beta blocker, typically timolol.

[3][4] The medical term for this is treatment of hypotrichosis; however, the U.S. Food and Drug Administration (FDA) approval is for purely cosmetic purposes (see Prostaglandin F receptor#Clinical significance).

[10] Some side effects are specific to the cosmetic formulation, which is applied to the skin at the base of the eyelash rather than instilled into the eye.

These include infection if the one-time applicators are reused, and darkening of the eyelid or of the area beneath the eye.

Like other PGF2α analogs such as travoprost, latanoprost and tafluprost, it increases the outflow of aqueous fluid from the eye and lowers intraocular pressure.

It is thought that bimatoprost mimics the human body's own prostamides (which are chemically similar), a class of substances related to prostaglandins, but with an unknown mechanism of action.

Bimatoprost and its endogenous analog prostaglandin F2α ethanolamide present the side-effect of being anti-adipogenic, and have been shown to be inducers of preadipocyte proliferation.