PrEP and side effects

Most people taking PrEP do not get side effects.

However, like all other medicines, PrEP has the potential to cause side effects.

In studies, mild nausea, diarrhoea, bloating and headache were reported in the first month by less than 1 in 10 people. These side effects then usually stop.

Occasionally, PrEP can cause more serious side effects that reduce kidney function and/or bone health. This is why kidney tests are run before and during PrEP use.

Changes in bone structure are usually small and reverse after stopping TD/FTC. This is similar to a commonly used oral contraceptive but might be important if younger than 30 when bones are still developing. Bone strength was not fully reversed after a year in one study in adolescents aged 15 to 19.

PrEP has not been linked to bone fractures.

Last updated: 1 November 2022.