While your friend may be taking HIV medications to treat his/her HIV, we do not recommend simply taking his/her medications. Sharing medications is a big no-no. This HIV prevention strategy is something that would need to be discussed with and monitored by your doctor. You will need to have lab work done to monitor side effects and your kidney function. It is definitely not an HIV prevention strategy we recommend doing on your own using another person’s medication that isn’t prescribed for you.