PEP and PrEP


Post-exposure prophylaxis (PEP) is a medication prescribed to individuals who are HIV negative and have potentially been exposed to HIV. Its purpose is to prevent HIV acquisition (becoming HIV positive). PEP should ideally be initiated within 72 hours of the exposure, with earlier initiation being more effective. It is generally not prescribed after 72 hours. PEP requires daily intake for a duration of 28 days.

Studies indicate that PEP reduces the risk of HIV infection by approximately 80%. However, it is important to note that PEP is not a cure for HIV and its effectiveness in preventing transmission may vary as certain strains of HIV can be resistant to the medication. Additionally, incorrect usage or delayed initiation may result in PEP failing to provide protection.

PEP can be obtained from emergency departments or sexual health services.

While taking PEP, individuals may experience side effects such as fatigue, nausea, diarrhea, and headaches.

PEP may be considered or recommended in the following situations:

  1. Your partner is known to be HIV positive, and you engaged in unprotected anal or vaginal sex with them, you shared drug injection equipment with them.
  2. You had unprotected vaginal or anal sex, or shared drug injection equipment with a partner whose HIV status is unknown or uncertain, but they belong to high-risk group where HIV rates are high. These groups include gay or bisexual men; individuals from high (>1%) HIV prevalence countries (e.g., Sub-Saharan Africa), and people who inject drugs from high-risk regions like Eastern Europe and Central Asia. If you had unprotected anal or vaginal sex with them, or shared drug injection equipment, PEP may be warranted.

If you have an HIV positive partner who has correctly and consistently taken HIV treatment for more than six months, they have an undetectable viral load, and they are your only partner, the risk of acquiring HIV is considered zero, and PEP may not be necessary.

Certain scenarios like human bites, semen splash to the eye, or oral sex typically do not warrant PEP. However, since many factors are involved in determining the need for PEP after exposure, it is advisable to seek medical attention promptly by visiting an emergency department or a sexual health clinic if you have any doubts.

Before starting PEP, you need to have an HIV test. This is because if you are already HIV positive, further tests are required to rule out drug resistance before initiating treatment.

Following the completion of the PEP course, additional HIV tests are required to confirm that you have not acquired HIV. It is also advisable to undergo testing for other blood-borne infections such as hepatitis B and hepatitis C, as well as a comprehensive screening for sexually transmitted infections like chlamydia, syphilis, and gonorrhea.


Pre-exposure prophylaxis (PrEP) is a medication regimen taken by individuals in the United States who are HIV negative to lower their chances of acquiring HIV. There are different ways to take PrEP. For example, you can take it daily for continuous protection or use "event-based" dosing, where you take the medication when you anticipate you will engage in sexual activity.

PrEP is highly effective and available in the United States. When taken consistently and correctly, PrEP provides almost 100% protection against HIV. Before starting PrEP and while taking it, regular HIV testing, screening for other sexually transmitted infections (STIs), and monitoring of kidney function are necessary.

Consider starting PrEP in the following scenarios:

  • Engaging in condomless sex with an HIV positive partner(s) who is not undergoing HIV treatment or has a detectable viral load.
  • Having used post-exposure prophylaxis (PEP) within the last few months.
  • Participating in chemsex, sex work, group sex, or sex parties.
  • Sharing drug injection equipment.
  • Identifying as a cis or transgender gay or bisexual man or a transgender woman and:
  • Having engaged in condomless anal sex in the past six months and expecting to do so again.
  • Recently receiving a diagnosis of Hepatitis C or syphilis.
  • Recently having an anal STI (gonorrhea, LGV, or chlamydia).

Even if you don't fit the specific descriptions mentioned, but still feel at high risk or have been clinically assessed as being at high risk of acquiring HIV, PrEP may be considered regardless of your gender or sexuality.

For more information about PrEP, you can visit reliable sources such as the Centers for Disease Control and Prevention (CDC) website or consult healthcare professionals familiar with PrEP.

Please note that personalized advice and guidance regarding PrEP initiation and ongoing care should be sought from healthcare professionals.