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How to take PrEP


PrEP can be taken as a daily tablet or “on-demand”.

Evidence shows that daily dosing is most effective. If taken seven out of seven days it is up to 99% effective.

If you take your PrEP pill every day, this will provide protection for a risk at any time during the period that PrEP is taken. Ideally you should start seven days before any risk. If in doubt, start with a double dose.

The “on-demand” method is only advised where the risk is from anal sex. (This was shown to be 86% effective overall in the French IPERGAY studay.) “On-demand” means you take PrEP just before and after a risk. This is also referred to as “event-based dosing” (EBD). There is less evidence for its effectiveness when this is taken less frequently than every week, e.g. 16 tablets per month.

If you are going on holiday and think you will be at risk, start seven days before and continue for a week after. If in doubt, start with two tablets.

PrEP clinics

To discuss PrEP in clinic, please call us on 0121 237 5700 and ask to be booked in for an appointment.