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Reduce Risks

PrEP (Pre-Exposure Prophylaxis)

The use of PrEP (Pre-Exposure Prophylaxis), a medication taken before exposure to the virus, is an approach to reducing the risk of infection.

PrEP is an effective weapon against HIV and can prevent infection with one tablet a day.

In addition to PrEP, there is also PEP (Post-Exposure Prophylaxis). However, neither of these protects you from other infections, so it is best to use another preventive method, such as a condom or diaphragm.

Legs with boots on the grass representing Pre-Exposure Prophylaxis (PrEP)

Índice

  1. Pre-Exposure Prophylaxis (PrEP)
  2. How can PrEP be taken?
  3. Risks and Side Effects of PrEP

Pre-Exposure Prophylaxis (PrEP)

Several studies have demonstrated the effectiveness of PrEP in reducing the risk of HIV infection.

This antiretroviral medication should only be taken by HIV-negative individuals—meaning those who are not infected with the virus—and before engaging in risky behavior.

After an assessment, a doctor evaluates the individual’s level of risk for HIV infection. Those at higher risk are advised to take PrEP on a scheduled basis.

In Portugal, PrEP is already an essential tool for preventing HIV transmission.

Following the World Health Organization (WHO) guidelines, PrEP should be used in situations such as receptive anal sex without protection, serodiscordant couples (where one partner is HIV-positive), people with a high number of sexual partners, and transgender men and women.

Nevertheless, in most central hospitals, everyone, regardless of their ethnicity, gender, or sexual orientation, can access assessment consultations for HIV PrEP through the National Health Service.

Need to know where to get advice about taking PrEP? Check our mapping.

How can PrEP be taken?

There are different ways to take PrEP depending on sexual practices:

  • Daily dosing: Recommended for people who have frequent sexual activity. This ensures a more consistent and protective level of medication in the blood and is suitable for vaginal and anal sex.

  • Intermittent (on-demand) dosing: Taken during periods of risk. This involves taking 2 pills before sexual activity (preferably 24 hours prior), 1 pill 24 hours after, and another pill 48 hours after. This method is recommended for people who engage in anal sex only.

Risks and Side Effects of PrEP

Before starting PrEP, it is important to consult a doctor to perform blood tests, check kidney health, and screen for any sexually transmitted infections, including HIV.

During the first month of use, PrEP may cause some side effects, such as:

  • Fever;

  • Nausea or vomiting;

  • Diarrhea and stomach pain;

  • Muscle and joint aches;

  • Headaches;

  • Increased sweating;

  • Swollen lymph nodes.

These effects should be monitored by a healthcare provider and can be treated with medications.

There are also reports of changes in kidney and liver function, as well as reduced bone density. However, these changes are reversible when PrEP is discontinued.

Individuals experiencing more severe side effects may be advised to take PrEP intermittently instead of daily.