Dihydrotestosterone

High levels of Testosterone causes high amounts of skin bacteria (Cutibacterium Acnes) which can go into the skin during a shoulder replacement surgery and cause a terrible infection. The goal of this experiment is to have participants take Finasteride, a medication that blocks testosterone production, for 2 weeks and evaluate the following: * Blood levels of testosterone * Amount of bacteria on the skin. Participants will: * Be assigned to take Finasteride, or a placebo (a look-alike pill with no active medicine) once daily, for 2 weeks * Have a small sample of their blood collected and their skin swabbed with a Q-tip to determine Testosterone levels and bacteria on the skin * Blood draw and skin testing will take place before starting Finasteride or the placebo (day 0) and at the end of the experiment (day 14).