PrEP Consent Guide For Gay & Bisexual Men

Thank you for your interest in PrEP

PrEP (pre-exposure prophylaxis) is a medicine you take to prevent HIV. This page walks you through what you need to know before you start, and the two ways you can take it. It’s part of the informed consent process, so take your time with it and bring any questions to your doctor.

Before you start: the key points

  • You need to be HIV negative to start PrEP. Your doctor will confirm this with a test before you begin, and you’ll be tested again every 3 months while you’re on it.

  • PrEP is very effective when you take it as prescribed. Research shows daily PrEP reduces the risk of getting HIV from sex by more than 99%. A small number of people worldwide have acquired HIV while on PrEP. These cases are rare and have usually involved either a drug-resistant strain or not enough medication in the body. Taking it as directed is what makes it work.

  • PrEP only protects against HIV. It does not protect against other STIs like syphilis, gonorrhoea or chlamydia. Condoms reduce the risk of those, and regular STI testing is part of being on PrEP.

  • PrEP can affect your kidneys. Rarely there can be a reduction in kidney filtration. This effect is usually small and reverses when PrEP is stopped. Tell your doctor if you’ve had any kidney problems or take other medicines that affect the kidneys. Your doctor will check your kidney function before you start and at your regular reviews.

  • There’s a small effect on bone density. Tell your doctor if you have osteoporosis, brittle bones, or a family history of either.

  • Your doctor will check your hepatitis B status with a blood test before you start, because the medicines in PrEP also act on hepatitis B. If you have hepatitis B, your doctor will talk you through which option is safest for you.

  • Some people get mild stomach upset when they start (nausea, bloating, looser stools). This usually settles within the first few weeks.

  • Regular review matters. Plan on a full sexual health screen and check-in with your PrEP doctor every 3 months.

If you develop any symptoms that worry you at any point, talk to your doctor.

Two ways to take PrEP

As a gay or bisexual man, you have two options, and both are recommended in the Australian guidelines:

  • Daily PrEP — one tablet every day. Best if you have sex often, or if you’d rather not have to plan ahead.
  • On-demand PrEP (also called 2-1-1) — you take it around specific sex, not every day. Best if your sex is less frequent and you can usually see it coming.

Both work well. You’re not locked in, and you can switch between them as your life changes. Talk through which fits you with your doctor.

Daily PrEP

  • Starting

    To start daily PrEP, you begin taking one tablet every day. After about 3 days of daily tablets, you’re protected for anal sex.

    If you need protection sooner (say a trip or a hookup is coming up fast), you can take two tablets together as your very first dose. That gets you to protective levels within about 2 hours. After that, carry on with one tablet every day.

  • Continuing

    Take one tablet every day. It doesn’t have to be the same time each day, though picking a set time makes it easier to remember.

  • Stopping

    If you want to stop, keep taking PrEP after your last anal sex: one tablet 24 hours after, and one tablet 48 hours after. Those two extra days keep protective levels in place to cover any recent exposure. Then you’re done.

On-demand PrEP (2-1-1)

On-demand dosing is well studied in gay and bisexual men having anal sex. In the IPERGAY trial it reduced the risk of HIV by around 86%, rising to around 97% in the follow-on study when taken correctly.

A few things to know:

  • On-demand only works with the tenofovir disoproxil/emtricitabine (TDF/FTC) form of PrEP, the one most people know as Truvada and its generics. It does not work with the tenofovir alafenamide (TAF/FTC) form, sold as Descovy.
  • It’s for anal sex. If you live with hepatitis B, PrEP on demand is not appropriate for you — daily PrEP will be best.

  • The 2-1-1 schedule

    • 2 tablets, taken together, 2 to 24 hours before sex.
    • 1 tablet 24 hours after that first double dose.
    • 1 tablet 24 hours after that (48 hours after the loading dose).

    If sex continues over several days, keep taking one tablet every 24 hours, and take your last one 48 hours after the final time you had sex.

  • A worked example

    You’ve got a date Saturday night. Take 2 tablets around lunchtime Saturday. Hook up that night. One tablet Sunday lunchtime, one tablet Monday lunchtime. Done.

  • The one thing that trips people up

    Set alarms for the 24-hour and 48-hour tablets. The most common way on-demand fails is people forget the follow-up pills once the sex is over. Those follow-up pills are the protection.

So, daily or on-demand?

Daily suits guys who have sex often, or who want one less thing to think about. On-demand suits guys whose sex is more occasional and planned-ish. Both are subsidised on the PBS. Your doctor can help you pick, and you can change your mind later.

When to see your doctor

Book in if you develop any symptoms that worry you, if you think you may have been exposed to HIV without protection in place, or if you’re due for your 3-monthly review.

Read this in your language

This consent guide is available in more than 70 languages.

This information is general in nature and not a substitute for personalised medical advice. PrEP is a prescription medicine. Speak to your doctor about whether it’s right for you and which option suits your situation.

— Dr George Forgan-Smith, GP, practising in Sydney and Melbourne