What Is PrEP?

  • PrEP stands for HIV Pre-Exposure Prophylaxis, meaning you take a medication before any exposure (sex or shared drug equipment to decrease the chance of HIV infection).
  • PrEP is part of an effective strategy used by HIV negative people to reduce their risk of becoming HIV positive.
  • PrEP will not protect you from any other infections.


What Medication Is Used And How Should I Take It?

  • PrEP consists of a single tablet that contains 2 medications – Tenofovir DF and Emtricitabine (Truvada).
  • Take 1 tablet daily, with or without food.
  • It will require 7 consecutive days of dosing to reach protective levels in your body against HIV for anal sex, and 21 days for vaginal sex.


Can I Take PrEP “on Demand” (“Disco Dosing”, Or “Condom Holidays”)?

  • The best current evidence is for daily PrEP use.
  • Some studies suggest that taking PrEP around the time of sex may be effective for anal sex (NOT vaginal or front sex). If you know that you might have condomless anal sex 24 hours in advance:
    • Take 2 pills 2 – 24 hours before sex.
    • Take 1 pill every 24 hours while having sex.
    • Take pills every 24 hours for 2 days after you stop having sex.


What If I Forget To Take A Dose?

  • Take the medication as soon as you remember, unless your next dose is due within the next 6 hours. In this case, resume at your usual time and do not double your dose.


What If I Decide To Stop PrEP?

  • Continue PrEP for 28 days after the last possible HIV exposure.
  • Follow up with your clinician for HIV testing 4-6 weeks after your last possible HIV exposure.


What Do I Need To Do While Taking PrEP?

  • Blood tests will be done every 3 months to monitor you for HIV infection and to check your kidneys. These tests are necessary for ongoing renewals of PrEP.
  • Routine tests for other sexually transmitted infections are also recommended every 3 months, as PrEP will not protect you against other infections.
  • It is recommended that PrEP be used with other strategies to reduce the risk of HIV, including condoms and avoiding sharing drug equipment.


What Are The Side Effects Of PrEP?

  • Some people experience nausea, diarrhea, bloating or headaches in the first few weeks. These side effects usually go away on their own.
  • Tenofovir may cause mild thinning of the bones, which seems to be corrected if PrEP is stopped. It is recommended that you get a protective amount of calcium (1000 mg per day) and vitamin D (400 IU – 1000 IU per day) from your diet and supplements to reduce possible bone effects.
  • Rarely, people can experience an allergic reaction, with rash, swelling, difficulty breathing. If these symptoms develop, you should be assessed immediately in the emergency department.
  • Tenofovir can rarely lead to kidney problems. Your kidney function will be monitored while you are on PrEP.
  • There has been one case of someone developing drug-resistant HIV while taking PrEP. If you experience symptoms that could be early HIV, see your doctor right away. Symptoms of early HIV include: fever, headache, joint pain, sore throat.