What is the MOA of bimatoprost 0.03% (Latisse)?

• A. Increases eyelash growth/thickening for hypotrichosis
• B. Reduces intraocular pressure
• C. Decreases tear production
• D. Inhibits ocular pigmentation

Answer: (A)

Bimatoprost works by acting on eyelash follicles to extend their growth phase and boost follicle activity, leading to longer, thicker, darker lashes. It’s a prostaglandin analog that targets FP receptors in the lash hair follicles, prolonging the anagen (growth) phase and increasing hair shaft size. This is the mechanism behind its cosmetic use for hypotrichosis of the lashes.

The other effects listed are not the basis for this indication: lowering intraocular pressure is how bimatoprost helps in glaucoma, not the lash-growth effect; decreasing tear production isn’t the intended action here; and inhibiting ocular pigmentation isn’t the mechanism for eyelash enhancement (though pigment changes can occur with prostaglandin analogs in some contexts).