Doctors can now "prescribe" lush lashes

Latisse is designed to treat a condition known as hypotrichosis of the eyelashes, which means a person does not have enough eyelashes.

The active ingredient in Latisse is bimatroprost, the same ingredient that is in Allergan's glaucoma treatment Lumigan. Patients taking Lumigan found a side effect of the drug to be eyelash growth, prompting Allergan to study it for the new use.

Latisse is a once-daily prescription treatment that is applied to the base of the upper eyelash with a sterile, single-use-per-eye disposable applicator. Once treatment is stopped, eyelashes will gradually return to where they were prior to treatment.

Allergan said it estimates global peak sales of Latisse solution could top $500 million a year.

Gary Nachman, an analyst at Leerink Swann, said that while approval was expected, "in this cautious environment, every approval through the FDA should be viewed positively."

Latisse is the first prescription product for lengthening eyelashes, making sales forecasting a little difficult.