Blog #6: Using PrEP (Dosing)

Taking PrEP depends on how far in advance and how regularly an HIV-negative person plans on having sex with someone who may be or is HIV-positive. Dosing can be adjusted according to one’s sexual activity.

There are the different frequencies of PrEP dosing with different purposes:

• DAILY dosing: for all forms of sex

  • 1 PrEP pill/day every day

  • Lead-in before sex with 7 days of daily dosing (preferably at the same time every day). It is generally safe to take pills a couple hours off from the typical time or miss a day once in a while (just don’t develop habits of doing so!).
    

• 4 PILLS/WEEK or T’S AND S’S dosing (Tue/Thu and Sat/Sun): for anal sex

  • Lead-in before sex with 7 days of daily dosing, then continue with 4 pills/week (e.g. on Tuesdays, Thursdays, Saturdays, and Sundays).

  • If a person only has sex once or twice a month, they may not need daily dosing. Taking 4 pills/week maintains a solid baseline of PrEP in one’s system. People can move up to daily pills if they become more sexually active.
    

• ON-DEMAND or EVENT-BASED dosing: for anal sex

  • If you know that you may have sex without condoms 24 hours in advance, take 2 pills 2-24 hours before sex, 1 pill 24 hours after that, and 1 more pill 24 hours after that.

  • If you are having sex for an extended period of time (e.g. over a few days), take 1 pill every 24 hours until you do not have sex for 2 consecutive days.

  • Unlike daily dosing, it is vital to not miss a single dose!

  • Not recommended if you have an active Hepatitis B infection.

Taking PrEP also involves medical visits every 3 months for HIV testing, screening for other sexually transmitted infections (STIs) and possible side effects, and ongoing support. Visit the PrEP Is For YOUth Clinic to learn more about starting/using PrEP!