With the cosmetic use of prostaglandin, which is found at a lower concentration in an eyelash serum as compared to glaucoma eye drops, noticeable lash growth is definitely a byproduct, but it’s not always glamorous. Optometrist Inna Lazar, OD, founder of Greenwich Eye Care and Dry Eye Spa in Connecticut, says she tried prescription lash growth serum Latisse (an FDA-approved medication with bimatoprost, also a prostaglandin analog) years ago when it was new to the market and it caused her to develop uncomfortable, “bushy” eyelashes. “My lashes were long, but they were very bushy and all over the place,” she says. “Plus I got hyperpigmentation on my lashline. With those side effects, I stopped using it.”