The robbery took place shortly before 7:00 p.m. at Fairmount Pharmacy located at 1900 Green Street.
Police say a man armed with a gun and wearing a white surgical mask entered the pharmacy and announced a holdup.
After receiving cash and four to five bottles of Xanax, the man fled the store on foot.
He is described as a white man, about 5'8 to 5'9, wearing a grey hooded sweatshirt, jeans and black sneakers.
No injuries were reported during the robbery.