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 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!