Q and A


Does PEP have side effects?


I am confused with PEP treatment, specifically about the side effects.

From sexual health charities I hear that PEP treatment can cause occasional side effects which may or may not go over the 28 days treatment. Another one (THT) says that the side effects are extreme and about 1 in 5 people on PEP stop taking it as a result.

The sexual health nurse said that side effects on PEP are very common and are severe.

I’ve heard from 3 people who have had PEP and they said that they didn’t get any side effects.

What’s the official line on PEP and side effects? I thought that PEP usually uses recommended triple therapy, using drugs that are well tolerated. Is the conflicting information I am receiving due to outdated data or current data?

Thank you for any clarity you provide.


All meds have some risk of side effects, but for PEP this risk is usually low. If side effects do occur, they are usually mild.

This depends on the meds used in the PEP combination.

In the UK in 2018, the PEP combination is usually raltegravir plus a combined pill with tenofovir DF/emtricitabine, which generally causes very few side effects, if any.

Even general side effects like nausea, diarrhoea and tiredness are not experienced by most people.

If mild side effects occur, they usually get easier after the first week or two as your body adjusts.

PEP that contains a drug called efavirenz is not recommended in the UK, though is used in some countries where there is less choice for HIV drugs. Efavirenz has a higher risk of side effects including mood changes and vivid dreams.

Discontinuation rates for PEP are often not very good. Studies of health workers who are exposed with a needle-stick injury report many people stop before the full month of treatment.

Note: This answer was updated in February 2018 from a question first posted online in June 2009.


  1. Roy Trevelion

    Hi Nthabiseng, Side effects with PEP, if they do happen, are usually mild. But the vaginal cramps and pains sound more serious. It’s a good idea to ask the doctor and find out what’s causing them.

  2. Nthabiseng

    my first day of using PEP (Tenofovir) and I am having a very irritating vaginal cramps and some vaginal pains. what could be the cause?

  3. Lisa Thorley

    Hi Gopolang,

    Its very unlikely that the weight loss will be due to the Tribuss. It may be due to stress.

  4. Gopolang


    I’v tested HIV negative after being raped as it was my status before the rape incident. .I was given the tribuss tablets as a measure of pep..I’m now 7 days on the treatment but I’ve lost a lot of weight. .what can I do to maintain my weight?

  5. Lisa Thorley

    H Brian,

    For info about PEP please see here:


  6. Brian

    hi.am Brian….i had sex with a lady i met for the first time.i used condoms well..later on, she confessed she is hiv +..i went to a doctor, and was enrolled on pep at around 65hrs after we had sex.will this help? am worried

  7. Lisa Thorley
  8. Bob

    My girlfriend had a fight with a friend,who ended biting her on his thumb finger.she went for test after 3hrs and she was -ve and was put on peps.is she safe for me to have sex with her?.that was on december she has not gone for a test again


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