How does PEP work?

PEP works by preventing HIV from reproducing before HIV infection can be established in a person’s body. As with other medications, it is important you take the pills as stated to maintain the right amount of the medication in your bloodstream at all times. This will mean that the medication will be as effective as possible.  PEP works best when taken at the right dose, at the right time, without missing doses.

How could the infection be stopped?

Taking two or three anti-HIV drugs everyday for four weeks might stop the HIV before it gets a permanent hold in the body. PEP is not a ‘morning after’ pill that’s taken just once – it’s one month of drugs.

But if HIV’s in the body, isn’t it too late?

No. After HIV gets into someone’s bloodstream it takes time (hours or a few days) before it permanently infects them. If someone acts in that short time, they stand a chance of stopping HIV before the infection takes hold.

So with PEP someone won’t become HIV positive?

Research seems to show PEP makes infection with HIV a lot less likely. But PEP doesn’t work every time - some people who take it still end up with HIV afterwards. It can fail because some anti-HIV drugs don’t work against some strains of HIV. And it’s more likely to fail if it’s not taken properly or soon enough.

How soon?

The quicker PEP is started the better – within hours. The longer the wait the more chance it won’t work. Also, some doctors won’t prescribe PEP after 48 or even 24 hours, so it is important that you don’t wait to seek PEP after you have been at risk. After 72 hours (three days) PEP usually isn’t given, because studies show it is unlikely to work by then.

Are the drugs the same as the ones taken by people with HIV?

Yes, it’s the same ‘combination therapy’ that’s taken by HIV positive people.

I have unresolved immigration issues, can I access PEP?

PEP is considered to be a life-saving emergency treatment and should be available to anyone regardless of their immigration status.

Is PEP is a cure for HIV?

There’s no cure for HIV. PEP can only stop an HIV infection if taken very soon after HIV has entered the body, before the infection takes hold - within the first 72 hours (three days). Once HIV infection takes hold and the infection becomes permanent then anti-HIV drugs cannot get rid of HIV from the body. This is because the virus is now in parts of the body that the drugs cannot reach. So once HIV permanently infects someone, the drugs can usually control the HIV in their body but can never get rid of it completely.

Does PEP have side effects?

Yes, it can cause diarrhoea, headaches, feeling sick and vomiting. Because of the side effects, many people taking PEP need time off work or study and some have to stop taking PEP. Side effects go once someone stops taking the drugs.