How should I take PrEP?
There are four different ways to take PrEP. The way you take it will largely depend on how and when you plan to have unprotected sex.
Daily use is the most effective, but isn’t the only way of taking it. If you’re not having sex regularly, taking it in another way that means you take less tablets can still be effective, and ultimately save you money. If you’re not sure what the best way to take it is, let us know, and we’ll give you the advice you need.
If you’re taking PrEP over a long period, you’ll also need to get tested regularly to make sure you don’t have HIV. This is a blood test usually done every three months.
Daily use
Like the name suggests, daily use of PrEP is where you take one pill every day at the same time. It’s suitable for you if you’re having anal or vaginal sex. Your protection starts after seven days of taking it like this. It’s a good way to protect yourself if you’re having sex regularly with an infected person.
T’s and S’s
T’s and S’s is where you take PrEP on specific days of the week: Tuesday, Thursday, Saturday and Sunday. It’s only suitable for anal sex and is a good form of protection if you have sex once or twice a month.
If you’re doing daily use or T’s and S’s, you should take your pill at the same time every day.
On-demand
Also called ‘event-based dosing’, on-demand is where you take:
- two pills 2-24 hours before you plan to have unprotected sex
- one pill 24 hours later
- and continuing to take one pill every 24 hours until you go two days without having sex.
It’s helpful if you know you’re having unprotected sex 24 hours in advance, but is only suitable for you if you’re having anal sex.
7-7-7
The 7-7-7 method, sometimes called ‘holiday PrEP’, is for when you plan to have sex multiple times, with multiple partners, within a short space of time. You’ll take one tablet a day for:
seven days before you ‘go on holiday’ (or your period of having sex starts)
every day during your holiday (your period of having sex)
and for seven days after your holiday (after your period of having sex finishes)
So the 7-7-7 name is based on your holiday lasting seven days, but it may be longer or shorter than this. It’s suitable for both vaginal and anal sex.
Can you take PrEP if you are HIV positive?
You shouldn’t take PrEP if you’re HIV positive, because it won’t help to suppress the virus in your body. To do this, the dose needs to be stronger. In fact, if you take PrEP but are HIV positive, it could make the drug less effective overall, because the dose is at a size where the virus can learn how to become resistant to it.
So if you’re HIV positive, you should speak to your GP or sexual health clinic about getting the treatment that’s right for you.
This page was medically reviewed by
Dr Daniel Atkinson, GP Clinical Lead on August 02, 2022. Next review due on August 01, 2024.