If you’re HIV-negative but at risk of exposure, PrEP is a medication you can take regularly to help prevent contracting the virus. But it comes with a few caveats.

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PrEP has only been around since 2012, so you’re not alone if you haven’t heard of it or have questions about it.

What is PrEP, is it right for you, and how can you get it if it is? We’ve got you covered.

PrEP stands for “pre-exposure prophylaxis,” meaning it’s a medication you take preventively before a potential exposure to HIV. It helps prevent you from contracting the virus. Think of PrEP like prepping for getting down.

Three different types of PrEP are available:

  • Truvada: a pill
  • Descovy: a pill
  • Apretude: an injection

PrEP is not to be confused with PEP, which is “post-exposure prophylaxis,” a different medication you can take right after a one-time interaction that potentially exposed you to HIV (kinda like how Plan B is used to prevent pregnancy).

Folks who take PrEP are HIV-negative adults and teens of any gender who regularly do things that come with a risk of contracting HIV.

It can be a fabulous option for:

  • people with penises who have sex with each other
  • couples in which one person has HIV and the other doesn’t
  • sex workers
  • people who use injection drugs
  • people whose partners use injection drugs
  • people who don’t regularly use condoms or other barrier methods when they have sex

Trials for the approval of Descovy didn’t include people with vaginas, so while Truvada is FDA-approved for the prevention of HIV through receptive vaginal intercourse, Descovy is not.

Apretude is used for people who are at risk of contracting HIV through sex. You must weigh at least 77 lbs (35 kg) to take this medication.

Who shouldn’t take PrEP?

PrEP isn’t for everyone. Talk with your doctor if you:

  • have had a previous allergic reaction to any of PrEP’s ingredients (tenofovir disoproxil, emtricitabine)
  • have severe liver problems
  • have severe kidney problems
  • have a weakened immune system
  • have hepatitis
  • are HIV positive
  • are pregnant
  • are breastfeeding

Additionally, if an HIV-positive partner’s viral load is considered undetectable and they continue to take their medications as prescribed, you may not need to take PrEP.

PreP can be taken in different ways:

  • Truvada and Descovy are pills that are taken once a day.
  • Apretude is first given as an injection once a month for 2 consecutive months at your doctor’s office. From there, you need to go in for a follow-up injection every 2 months.

Regardless of which form of PrEP you take, it’s important to stick with your medication schedule. That’s what makes it most effective.

If you take a pill, consider making it a part of your routine — maybe take it right before you settle in for an evening of Insta scrolling. If you get the injection, stick with your regularly scheduled visits.

PrEP is a prescription medication. If you’d like to get on PrEP, you’ll first need to find a healthcare professional who will prescribe it to you.

If you already have a doctor, you can talk with them about starting PrEP. If you need a new doctor, lots of community health centers offer PrEP prescribers — you can use this locator to find someone.

PrEP is only for people who are HIV-negative, so your doc will do an HIV test first. They may do other tests as well in order to get you started. You’ll have to repeat these tests every 3 months to keep taking oral PrEP, or before each scheduled injection.

Some PrEP providers offer a telemedicine option and self-testing to make it even easier for you.


According to the CDC, when taken as prescribed, PrEP is 99% effective at reducing the risk of contracting HIV from sex. It doesn’t get much more effective than that!

If you might get HIV from injecting drugs instead of from sex, PrEP reduces your risk of getting HIV by at least 74% in that case (again, when taken as prescribed).

The key here is that PrEP it’s much less effective when you don’t take it exactly as prescribed, though it’ll still help somewhat.

While the CDC doesn’t officially recommend it, there’s evidence that a method known as “on-demand PrEP” — where you take a few doses in just the days and hours directly before and after having sex without a condom or other barrier method — can be effective for some people.

It takes 1–3 weeks of consistent use for PrEP to reach maximum effectiveness, depending on the activity you’re engaging in.

PrEP can be very expensive and in some cases cost well over $1,000 per month. However, there are only a few situations where you’d have to pay all that yourself — and for most people, it’s totally free.

You do need to have ongoing medical visits and lab tests to keep getting the prescription, so those have to be paid for as well. If you have health insurance, there’s a good chance your plan covers the medication, clinic visits, and lab tests.

If you have copays for any of these, you can apply for copay assistance through the drug’s manufacturer. However, these types of programs typically only assist with copays for private insurance, not for public plans like Medicare and Medicaid — but those don’t usually have copays anyway.

Not covered by health insurance? Apply for free PrEP through Ready, Set, PrEP, a program offered by the U.S. Department of Health and Human Services. Each drug’s manufacturer also provides programs to help cover the cost of the medication for those who are uninsured.

There are many other options for discounts and help to pay for PrEP and the accompanying visits. For a list of state-by-state assistance programs and other options, visit NASTAD’s page on the topic.

Some programs depend on income while others don’t, so check out what’s available for your unique situation. Your prescriber can also probably help point you in the right direction.

Some people taking PrEP experience mild, temporary side effects that go away over time, such as:

  • nausea
  • diarrhea
  • headaches
  • fatigue
  • stomach pain

The National Institutes of Health says the side effects are not serious. So, while they’re not fun, they shouldn’t be severe and should fade away. If you do have serious or prolonged side effects, tell your prescriber ASAP.

Some researchers are exploring whether taking PrEP might make a person resistant to HIV medications if they do get HIV. But so far the research shows that this is infrequent and is most likely to happen when the person starts taking PrEP when they’re already HIV-positive.

Since PrEP is only for HIV-negative people, an HIV-positive person would be taking PrEP only if the HIV test given at the beginning of the prescription process showed a false negative (which can happen if the infection is very new) or if they got HIV while taking PrEP.

That said, it’s very rare to get HIV while taking PrEP as prescribed, but it becomes more possible if you don’t take it exactly as prescribed.

If you’re looking for peace of mind while having sex with or sharing needles with folks who might be living with HIV, PrEP is a proactive way to increase your chances of staying HIV-negative.

It’s effective, but you do need to keep up with testing to continue taking it. Some people may also need to fill out paperwork to cover the cost of the mediation. The effort is worth it for many people, especially since taking this medication helps you keep doing you … and others.