Yes, but there are two problems:

1) You can't guarantee they are real. The upside of buying drugs in the US is that if you get fake pills, it is a huge deal and people get sued out of business for this. Rite Aid (A national drugstore chain) got caught shorting the pill count in prescriptions and they got into big trouble.

2) The Department of Homeland Security will open packages from companies that they suspect are selling medicines from abroad and shipping to the US and impound the pills. The odds are good that you won't get caught, but if you do, it can become a real hassle.