What are the Side Effects of PrEP?

PrEP (also known as pre-exposure prophylaxis) is a medication regimen that can be extremely effective at preventing HIV transmission. This medication works by preventing the virus from reproducing within the body.

Many people who are considering taking this medication wonder: what are the side effects of PrEP?

Sadly, the fear of side effects from PrEP holds many people back from taking this medication – even though they are at high risk for HIV transmission.

In a recent medical study, 42% of respondents stated that the number one reason why they did not take PrEP was because they didn’t want to experience any negative side effects.

First and foremost, it is important to state that the majority of people taking PrEP do not experience any side effects at all. Medical studies showed that a very small percentage (just 2% in some studies) of participants reported adverse effects from the medication.

Of course, every person’s body will react differently to a medication. Some people are more sensitive to medication and may experience different side effects of PrEP than others. Additionally, factors like current health issues, allergies, or other medications can influence your body’s reaction to any medication regimen.

So, what are the side effects of PrEP, and should you be concerned about them?

Let’s discuss.

1. Start-Up Period Side Effects

Generally, most of the side effects of PrEP occur during the “start-up” period when you first start taking the medication. This often happens in the first few weeks and normally are quite tolerable.

The most common side effects that patients experience include:

  • Headaches
  • Nausea
  • Vomiting
  • Dizziness
  • Loss of appetite
  • Rash
  • Weight fluctuations
  • Abdominal pain or discomfort
  • Tiredness

Most of these side effects arise because PrEP increases the levels of liver enzymes to fight HIV. This can cause gastrointestinal issues and may increase bloating, gas, or cause constipation.

If you experience any of the side effects of PrEP, you can bring your concerns to your doctor. Usually, over-the-counter medication can be used to help with issues like headaches, nausea, or upset stomach problems.

The side effects of PrEP can vary depending on which medication you take. Descovy and Truvada are currently the two types of medication available for PrEP. Since each medication has a unique formula,  side effects of Truvada are somewhat different than the Descovy side effects.

1. Side Effects of Truvada

Truvada was the first HIV PrEP medication approved by the FDA. It is approved for cisgender and transgender males and females and uses a combination of emtricitabine and tenofovir to block enzymes HIV creates to reproduce.

In addition to the common side effects during the start-up period, some patients taking Truvada for PrEP had additional side effects. The most common side effects of Truvada were headaches (7%), stomach pain (4%), and weight loss (3%).

One significant side effect of Truvada is its effect on kidney function and health. Truvada can decrease the filtering capacity of the kidneys. Most doctors will monitor the patient’s kidney function and health through blood and urine tests while the patient takes PrEP. For patients with pre-existing conditions, Truvada may increase the likelihood of kidney problems or failure.

Truvada can also decrease bone density, which leaves the body more vulnerable to fractures. However, medical studies show that this bone density loss is reversible and generally quite mild.

2. Side Effects of Descovy

Descovy is currently only approved for cisgender males and transgender females – although it is being tested for all genders. This medication uses a different drug formulation that includes antiretroviral agents to decrease the viral load of HIV and stop the virus from reproducing.

In a recent drug trial, just 1% of participants stopped taking Descovy due to adverse side effects. Additionally, a slightly smaller percentage of patients experienced the most common side effects of Descovy, including diarrhea, nausea, headache, fatigue, and stomach issues.


Descovy can also diminish the filtering capacity of the kidneys, especially for people with pre-existing issues. Additionally, some of the more serious side effects of Descovy include increase lactic acid in the blood and liver problems. However, these side effects are extremely rare.

3. What Side Effects to Look Out For

It is important to mention any concerns or pre-existing health conditions (such as hepatitis or kidney problems) to your doctor before taking PrEP. You should also follow the recommended testing regimen from your doctor so they can closely monitor your health.

If you notice any sudden changes to your health while taking PrEP, contact your doctor right away. There are some warning signs to look out for while taking PrEP, as they could signal potentially serious health concerns. This includes:

  • Yellowing of the skin or eyes
  • Loss of appetite for an extended period
  • Change of color in urine or stool
  • Excessive abdominal pain
  • Fast or abnormal heartbeat
  • Shortness of breath
  • Bone pain or tenderness


Ultimately, the benefits of PrEP far outweigh any potential side effects of PrEP, and putting yourself or your partners at risk of HIV transmission. For the majority of people, the side effects are quite minimal and manageable. However, you should always bring up any concerns or health changes to your doctor right away.

If you have any further questions about getting PrEP, please reach out to PrEP Daily. We have a team of navigators who will work with you one-on-one to answer any questions you have about taking PrEP. They can also get you connected with a local health provider to see if PrEP is the best choice for you.