What are the side effects of injectable PrEP?

Injectable PrEP is very well-tolerated by the vast majority of people.

When side effects do occur, they are generally mild, temporary, and entirely manageable. Here is what is most often observed.


The main side effect: injection site reactions

This is by far the most common and expected effect. It is normal to experience a local reaction after the injection into the gluteal muscle. These reactions are generally mild to moderate and fade on their own within a few days. The most frequent are:

  • Pain or tenderness to the touch
  • Redness or mild swelling
  • Induration (a small lump or hardened area under the skin)

Most people report that these reactions decrease in intensity after the first few injections.

Other possible side effects

Less often, other effects may be felt, especially in the days following the injection. They are generally short-lived.

  • Flu-like symptoms: It is possible to experience fatigue, body aches, headaches, or a low-grade fever.
  • Rarer effects: Very few people report dizziness or mild digestive issues.

How to manage these effects

The good news is that most of these effects can be easily alleviated.

  • For pain at the injection site: You can apply a cold compress or gently massage the area.
  • For other symptoms: Rest is often sufficient. For headaches or fever, you can take an over-the-counter pain reliever like acetaminophen (Tylenol®) or ibuprofen (Advil®), after checking with your pharmacist.

If a side effect seems severe, does not improve after a few days, or worries you, it is important to contact us to discuss it.