PEP – Post-Exposure Prophylaxis for HIV

Page last reviewed 15.2.2024

What is PEP?

PEP, Post-Exposure Prophylaxis, is a medication that effectively prevents HIV infection when taken within 72 hours of potential exposure to HIV. The medication is taken as a 28 day course. The national guidelines for post-exposure prophylaxis was published in 2018.

Who is PEP meant for?

If you don’t know if your sexual partner is HIV-positive or whether they are on effective HIV medication and you did not use a condom, the following sexual situations are considered high risk in relation to HIV exposure:

  • Anal sex without a condom in sex between men.
  • Vaginal and anal intercourse without a condom with a person from a high prevalence country (for example parts of sub-Saharan Africa)
  • Vaginal or anal intercourse without a condom with a person selling or buying sex.
  • Vaginal or anal intercourse without a condom with a person who injects drugs.
  • Vaginal or anal intercourse without a condom with a person living with HIV who is not on HIV medication.
The diagram shows a picture of the situations in which PEP medication should be considered within 72 hours of the exposure of HIV. PEP medication is not needed after sex without a condom if an HIV-positive partner is on effective HIV treatment.

How is it used?

A doctor can prescribe PEP after situations where you have an elevated HIV risk. The medication has to be started within 72 hours of the unprotected sexual intercourse. The earlier the medication is started the better it protects against HIV. Any doctor can determine the need for PEP after which a referral is made to a doctor specialized in infectious diseases. Before starting the PEP medication, you will be tested for HIV to make sure you are not HIV positive already.

If you have had a high risk situation, contact your health center or emergency health center.

The prevalence of HIV is significantly higher in many travel destinations than it is in Finland. In some countries, such as Thailand (link in Finnish), it is possible to access PEP medication with a prescription in private hospitals.

Follow-up of HIV exposure

After PEP medication the HIV test is conducted both right after the 28 days and four months after the exposure to HIV.

When an HIV risk situation is associated with unprotected sex, it is important to test also other sexually transmitted infections. STIs can be asymptomatic and often cannot be detected without a test. Tell your doctor what kind of sex you have had to make sure the samples are taken from the right places. For example, chlamydia and gonorrhea should be tested differently according to what kind of sex you have had: from urine, and/or with a swab sample from anus and/or throat. HIV and syphilis are tested on a blood sample.

In what kind of situation is PEP not needed?

A person living with HIV who is on medication does not transmit HIV when the virus level is undetectable. Not even through unprotected sex. So the PEP medication is not needed if it is known that the sex partner is on effective HIV medication. Effective medication means that the amount of HI-viruses in the blood is less than 200 copies/milliliter for at least 6 months prior to the exposure situation.

PEP-medication is also not needed if the condom has been in use throughout intercourse or the person is on PrEP medication (Pre-Exposure Prophylaxis).

Also, oral sex without a condom or oral sex protection is not a prerequisite for PEP medication, as the risk of getting HIV in oral sex is extremely low.

This guideline has been written in collaboration with infectious disease doctors. You can get more information from Hivpoint’s phone helpline and chat counselling.