PrEP (Pre-Exposure Prophylaxis)

What is PrEP?

PrEP stands for Pre Exposure Prophylaxis. 

It is a way for an HIV negative person to use HIV drugs to protect against catching HIV.

PrEP is now available free in the UK on the NHS.

Oral PrEP uses two HIV drugs in one pill. These are usually tenofovir disoproxil (TD, TDF) and emtricitabine (FTC). In 2019, the US FDA approved a new version of oral PrEP that used tenofovir alafenamide (TAF) with FTC. This approval was only based on studies in gay and bisexual men and trans women.

For highest levels of protection PrEP needs to be taken before and after sex.

Most PrEP studies – including the UK PROUD study – involved taking one pill every day, even when not having sex. 

In studies where people were good at taking PrEP, there was close to 100% protection.

Some people can take PrEP just when they need it, rather than every day. This is called on-demand dosing.

This involves taking a double-dose (two pills) 24 to 2 hours before sex. Then a single pill at 24 and 48 hours after the first dose.

If you are the receptive partner, on-demand dosing only protects for anal (not vaginal) sex. Daily dosing works for the receptive partner in both anal and vaginal sex. On-demand dosing work for the insertive partner for all types of sex.

PrEP was approved in the US in 2012 and was quickly included as a key recommendation in World Health Organization (WHO) guidelines. PrEP was only approved in Europe in July 2016.

Although it took a long time, PrEP in now available free from the NHS across the UK.

Some people in the UK still buy generic PrEP online. This is just as effective as the brand name drug but much cheaper. It is legal and safe to buy onlne meds. The cost is approximately £17.50 for 30 tablets.

More information

New guide to PrEP in the UK (June 2021):

See also this link for more information.

Last updated: 1 June 2021.