PrEP FAQ

PrEP works by blocking an enzyme called HIV reverse transcriptase. By blocking this enzyme, HIV is prevented from replicating itself inside the body.

Truvada is the first FDA approved drug for PrEP. It is taken once daily and it can be taken by both men and women. It’s two active ingredients are emtricitabine and tenofovir.

Descovy is the second FDA approved drug for PrEP. It is also taken once daily but can only be taken by cisgender men and transgender women. 

Yes, but you should always disclose what other medications you’re on to your prescribing physician. 

You can receive free online PrEP and STI testing through MISTR. MISTR is available in all 50 states including D.C and Puerto Rico with or without insurance.

PrEP takes about 7 days before it is fully effective in rectal tissue, and take up to 20 days for vaginal tissue. However, the CDC recommends taking PrEP every day for 21 days prior to any possible exposure to HIV. The drug must be potent enough in the bloodstream to block HIV infection. Taking a pill right before or immediately after possible exposure to the virus will not protect against a potential HIV infection.

PrEP is most effective when taken every single day. If you take PrEP daily, the level of protection is about 99%. If you take PrEP four times per week, the level of protection is about 96%. When taken less than 4 days per week, the potency of the drug in the bloodstream is greatly reduced, and the drug’s effectiveness drops dramatically. If you miss a dose, make sure to take the next one, but there is no need to double up.

Those taking PrEP report little to no side effects, but symptoms such as headache, abdominal pain, and weight loss can happen. These side effects typically do not last long and often go away entirely within the first month. If you’re experiencing prolonged side effects, please let your doctor know.