Question
PrEP question about dosing
9 April 2024. Related: All topics, PrEP.
Hello, I am a gay male. I use prep on demand. I took 2 pills on day 1 and continued with 1 pill on day 2 and another 1 pill on day 3. In total I took 4 pills. However, I did not have sex. I stopped taking the prep, now for 5 days. I want to have sex tonight. Can I restart with 1 pill, because it was so recent, or do I need to restart with 2 pills, and then continue with 1 pill every day after sex?
Thank you.
Answer
Hi there
Please see detailed info on event-based 2:1:1 dosing in this updated guide:
https://i-base.info/guides/prep
Either way, there is unlikely to be much difference whether you started with a double dose again or not. Dosing can be very flexible and levels of PrEP would have been good either way.
Hi James, this was a few days ago, this will all have been fine. After the first double dose, then roughly taking PrEP each day you are having sex will be okay. The just take single dose of PrEP each day for the next two days after you stop sex. Approximate dosing times are okay.
https://i-base.info/guides/prep
Hi i event base dose, if i took a double dose at 1pm friday (no sex) then took my next single dose late on Saturday at 9pm (sex today) if i take my third dose and a fourth at the original 1pm time am i still covered?
Hi Mark and thanks for getting in touch.
I would start with a double dose for an extra layer of protection but you are safe to start with a single dose as well
Hi wondering if you can help? I take prep on demand, I took my double dose of prep 2 days ago on sunday, followed by 1 dose 24hrs later on monday and sex occurred that day but protected , i then missed my third dose (tuesday) as i forgot however sex was protected, if I was now to have sex unprotected on thursday (48hrs) after my suposed 3rd dose would you start again with a double dose?
Hello dear confused,
I will stand by Simon’s answer: better to take PrEP than not.
Dear Simon,
Thanks for your answer! So the fact that I had sex 20 minutes before the 2-hour mark (so 20 minutes earlier than what the guidelines say), after the first double dose of 2-1-1, would not have a significant impact on the efficacy of PrEP, right? I of course took the two subsequent single doses.
Thanks again!
Dear confused, being a little late will still have a good chance of working and having some PrEP is always better than having none.
Hello,
Thanks for this excellent service! Just to clarify, I think someone has asked something similar. I took PrEP on demand (2-1-1), but I realized I had sex 1 hour and 30-40 minutes after the first double dose, instead of waiting 2 full hours. Would the fact that I had sex 30-20 minutes earlier than I was supposed to affect the effectiveness? Should I seek PEP? I’m very worried about this possible exposure.
Thank you!