Daily PrEP is the most common way people taking PrEP. It’s as simple as taking one pill every day.
You need to take daily PrEP for 7 days before you get full protection. If you are a cisgender (not trans) man who has sex with men, you can also start with a single dose of two PrEP pills at least 2-24 hours before sex to achieve highly protective levels of PrEP, and then continue with daily PrEP (this is not suitable for anyone else).
It’s best to take PrEP every day, and this helps you keep to a routine. But if you miss a dose, daily PrEP still provides very high levels of protection if your only possible risk for HIV is from anal sex. If you take less than four pills in a week though, PrEP may not give you full protection.
If you’re having front hole or vaginal sex, it’s really important to take PrEP every day to make sure you get full protection.
It’s also ok to take PrEP if you’re taking transition-related hormones. Though for women of trans experience taking feminising hormones, it’s important to take PrEP every day.
It’s also really important to make sure you take your PrEP every day if you have hepatitis B. This is because the drugs in PrEP are also used in the treatment of hepatitis B, so if you miss doses it can cause complications with your hepatitis B and your liver.
If you have hepatitis B, you should discuss this with your PrEP prescriber (doctor or nurse practitioner), so that you have a clear plan on how to stop PrEP if you decide that you no longer want to take it.
You can find some tips to help you to remember to take you PrEP every day here.
Daily PrEP can also include taking PrEP for short periods, such as over a holiday.
If you want to stop taking PrEP or take a break for any reason, have a chat to your doctor first. If you are a cisgender man who has sex with men and you want to stop taking PrEP, it’s currently recommended that you keep taking daily PrEP for two consecutive days (24 and 48 hours) after your last possible exposure to HIV. For anyone else, you need to continue taking PrEP daily for 28 days after your last possible exposure to HIV. If you had any HIV risks while you weren’t on PrEP you will need a repeat HIV test before you recommence PrEP. And make sure you follow the steps to get full protection again before any potential exposures to HIV.
If you stop PrEP, it’s important that you have a plan to re-start PrEP if you feel that you might need it, and a plan to manage HIV exposures while off PrEP.
On-demand (or event-based) PrEP is taking PrEP around the times you have sex. For this to work, you need to know when you’re planning to have sex in advance. You need to understand the dosing schedule and it is really important not to miss any doses. Otherwise it may not give you full protection.
On-demand PrEP is only suitable if you’re having anal sex. If you’re having front hole or vaginal sex, it doesn’t provide enough protection, so daily PrEP is recommended.
On-demand PrEP is not suitable for women of trans experience who are taking feminising hormones. The full effect of taking feminising hormones on PrEP levels in the body is still being determined, so daily PrEP is recommended.
On-demand PrEP is also not suitable if you have hepatitis B. This is because the drugs in PrEP are also used in the treatment of hepatitis B, so intermittent use of PrEP can cause complications.
If you’re having sex regularly enough anyway, or you don’t think you can plan when you’ll be having sex, daily PrEP might be the best option for you.
To take on-demand PrEP, you need to:
- Take two pills together, between 2 and 24 hours before sex, and then
- One pill every day until 48 hours has passed after the last time you have sex.
There is a fact sheet about on-demand PrEP here.
Talk to your doctor before considering on-demand PrEP. They may wish to consider the Australian PrEP clinical guidelines.