People are talking about non-daily PrEP dosing at the moment – so now is a good time to understand what it actually is and how to do it as safely as you can, if you can’t commit to taking it daily.

1) What is non-daily PrEP (also known as ‘on-demand’ or ‘event-based’ dosing)?

In New Zealand, PrEP is prescribed as a daily medication. People take one pill every day, usually at the same time, and the medication builds up in their system to a point where it protects them from HIV infection.

Non-daily PrEP is different in that – as the name suggests – people don’t take it every day. Usually they will take 4 pills:

• Two pills 2-24 hours before sex
• One pill 24 hours later
• One more pill 24 hours after that

There is evidence that event-based dosing is effective if you’re using it regularly (for example if you’re having sex weekly). If you’re using it less often (for example, once every month or two), the evidence of effectiveness is less clear. We recommend daily dosing as the most effective way of using PrEP. Overall, there is evidence suggesting that non-daily PrEP may be highly effective as a strategy - it’s just really important to take extra care and make sure you talk to your doctor regularly. 

2) Talk to your doctor

In New Zealand, PrEP is approved for daily dosing only. Doctors can technically prescribe it for non-daily dosing – but it is not yet approved by MedSafe for this purpose.

Your doctor is there to support you through your PrEP journey, so if you’re considering non-daily-dosing then make sure you’ve discussed it with them (and that you’re getting it from them – not from your friends or fuckbuddies). Not only will this mean they can give you the proper care, but it’s a chance for them to read up about it and gain knowledge to share with their other patients.

Getting PrEP from a doctor also means you’ll be tested to make sure you are HIV-negative before you start taking the pills. If you are living with HIV, then starting PrEP can make treatment options more difficult, as the virus can develop resistance to some of the drugs in PrEP.

Non-daily PrEP is not recommended if you have an active hepatitis B infection. The drugs in PrEP also suppress the hepatitis B virus, so starting and stopping PrEP can cause virus flare-ups and liver inflammation.

3) Keep up your 3-monthly checks

PrEP is not just about the pill itself - it’s a whole regime which includes a 3-monthly catchup with your doctor. This will include tests for HIV and other STIs, as well as a test to make sure PrEP isn’t interfering with your kidney function.

If you choose to take non-daily PrEP, it’s important to still see your PrEP prescriber every three months for HIV and STI testing, even if you have spare pills left over. If you aren’t using condoms for casual sex then it’s especially important, as the likelihood of having an STI like syphilis or gonorrhoea will be much higher. Getting these diagnosed and treated quickly is best for you, and to reduce the risk of passing them on to your partners.