The Three PrEP Options and How to Choose

The three PrEP options, at a glance

pre-exposure prophylaxis (PrEP) is medicine taken before any exposure to keep HIV from ever taking hold. In the United States it comes in three forms: two once-daily pills, Truvada and Descovy, and one long-acting injection, Apretude, given by a provider on a schedule. All three are prevention rather than treatment, and all three work only against HIV 1Ref 1Centers for Disease Control and Prevention (2024).Clinical Guidance for PrEP.That PrEP comes in oral and injectable (cabotegravir) forms, that taken as prescribed it lowers the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%, and that PrEP does not protect against other STIs..

The pills and the shot are not three versions of the same thing. Truvada is a daily tablet combining emtricitabine and tenofovir disoproxil fumarate, and it is also sold as a lower-cost generic. Descovy is a daily tablet combining emtricitabine with a newer form of tenofovir, formulated to be easier on the kidneys and bones. Apretude is cabotegravir, an injection a clinician gives roughly every two months after a short lead-in — nothing you keep or take at home.

Knowing which of the three a headline is talking about is the first real step, because the trade-offs that matter — a daily pill habit versus a clinic visit, cost, and who each one is approved for — fall along exactly those lines.

Who should consider PrEP?

PrEP is for people who do not have HIV but could be exposed to it, and the bar for considering it is deliberately low. The U.S. guideline asks providers to tell every sexually active adolescent and adult that PrEP exists, rather than waiting for a patient to fit a narrow profile 2Ref 2Centers for Disease Control and Prevention / US Public Health Service (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2021 Update: A Clinical Practice Guideline.That the U.S. PrEP guideline asks providers to inform all sexually active adolescents and adults about PrEP and to match the option to the person, and that prescribing PrEP includes baseline confirmation of HIV status and ongoing testing and monitoring.. The idea is that PrEP should be a normal part of the sexual-health conversation, not a last resort.

In practice, people weigh PrEP when they have ongoing situations that carry HIV risk — a partner living with HIV whose status is not confirmed undetectable, more than one partner, inconsistent condom use, a recent bacterial STI, or sharing injection equipment. None of these is a requirement, and the point is not to sort people into worthy and unworthy. It is that anyone worried enough to ask is someone the guideline says should be offered the conversation 2Ref 2Centers for Disease Control and Prevention / US Public Health Service (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2021 Update: A Clinical Practice Guideline.That the U.S. PrEP guideline asks providers to inform all sexually active adolescents and adults about PrEP and to match the option to the person, and that prescribing PrEP includes baseline confirmation of HIV status and ongoing testing and monitoring.. If you are reading this and wondering whether PrEP applies to you, that wondering is itself a reasonable reason to raise it with a clinician. Starting is more accessible than many people expect — primary care, sexual-health clinics, and telehealth can all prescribe it — so access is rarely the real obstacle; the harder step is usually just asking.

How well does each PrEP option work?

Taken as prescribed, PrEP is highly effective: the CDC estimates it lowers the risk of getting HIV from sex by about 99 percent, and from injection drug use by at least 74 percent 1Ref 1Centers for Disease Control and Prevention (2024).Clinical Guidance for PrEP.That PrEP comes in oral and injectable (cabotegravir) forms, that taken as prescribed it lowers the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%, and that PrEP does not protect against other STIs.. Those figures describe PrEP taken consistently. The number people usually quote is for the daily pills used correctly, and missing doses is where real-world protection slips — which is part of why the injection exists at all. Being honest with yourself about your own routine, then, matters more than picking the theoretically strongest drug; the best regimen is the one that survives a chaotic week.

taken as prescribed, PrEP reduces the risk of getting HIV from sex by about 99% 1Ref 1Centers for Disease Control and Prevention (2024).Clinical Guidance for PrEP.That PrEP comes in oral and injectable (cabotegravir) forms, that taken as prescribed it lowers the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%, and that PrEP does not protect against other STIs.. The injection keeps medicine in the body between visits, so protection does not depend on remembering anything each morning. That is its central advantage: for someone whose adherence to a daily pill is shaky, a shot every couple of months can deliver steadier real-world protection even though the pills are just as effective on paper. How well PrEP works, in other words, is less about which product is objectively strongest and more about which one you can actually stay on. That distinction — efficacy on paper versus effectiveness in a real life — is the reason there is more than one option, and it is worth reading more on how well PrEP works before deciding.

How do you choose between Truvada, Descovy, and Apretude?

The choice is a clinical match, not a ranking. The U.S. guideline behind PrEP asks providers to tell every sexually active adolescent and adult that PrEP exists, then to fit the specific option to the person — their kidney and bone health, whether they can keep a daily pill going, their exposures, and their own preference 2Ref 2Centers for Disease Control and Prevention / US Public Health Service (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2021 Update: A Clinical Practice Guideline.That the U.S. PrEP guideline asks providers to inform all sexually active adolescents and adults about PrEP and to match the option to the person, and that prescribing PrEP includes baseline confirmation of HIV status and ongoing testing and monitoring.. There is no single best PrEP; there is the one that fits you.

A real difference between the pills. Descovy has not been approved for people who could get HIV through receptive vaginal sex, because the study that led to its approval did not include that group. Truvada and its generics are approved across those exposures. That single fact is why the pill choice is a conversation rather than a coin flip, and it is a large part of why the question of whether PrEP works for women has an answer of its own worth reading. Apretude is the injectable PrEP option, and choosing it is really choosing a rhythm — a clinic visit every couple of months instead of a daily habit. Cost and insurance coverage differ across the three as well, which is a fair thing to ask about up front. A clinician weighs all of this with you; the point of knowing it going in is to ask sharper questions.

None of the three protects against other STIs

Every PrEP option prevents HIV and nothing else. PrEP does not protect against gonorrhea, chlamydia, syphilis, herpes, or any other sexually transmitted infection 1Ref 1Centers for Disease Control and Prevention (2024).Clinical Guidance for PrEP.That PrEP comes in oral and injectable (cabotegravir) forms, that taken as prescribed it lowers the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%, and that PrEP does not protect against other STIs.. This is the most common misunderstanding about PrEP, and it matters, because someone who feels fully covered may test less often exactly when regular testing counts most.

Two tools fill that gap. Condoms lower the risk of most STIs that PrEP ignores. And for some people, doxy-PEP — the antibiotic doxycycline taken shortly after sex — is offered to cut the risk of bacterial STIs; the CDC's 2024 guidance recommends counseling on it for gay and bisexual men and transgender women who had syphilis, chlamydia, or gonorrhea in the past year 3Ref 3Bachmann LH, Barbee LA, Chan P, et al. (Centers for Disease Control and Prevention) (2024).CDC Clinical Guidelines on the Use of Doxycycline Postexposure Prophylaxis for Bacterial Sexually Transmitted Infection Prevention, United States, 2024.That the CDC's 2024 doxy-PEP guidance recommends counseling on doxycycline taken after sex to reduce bacterial STIs for gay and bisexual men and transgender women who had syphilis, chlamydia, or gonorrhea in the prior 12 months.. Because PrEP already brings you into care every few months, it is a natural anchor for a testing routine: the same visits that keep PrEP safe can catch the infections it does not prevent. Understanding the doxy-pep after sex antibiotic as a separate layer — not a replacement for anything — keeps the two straight.

PrEP prevents exposure; it does not rescue one that already happened

PrEP is for the time before a possible exposure. If a condom broke last night, or you had sex you are now worried about, PrEP is not the tool for that moment. a possible exposure that already happened is handled by PEP — post-exposure prophylaxis — which must be started as soon as possible and within 72 hours 4Ref 4Centers for Disease Control and Prevention (2024).Clinical Guidance for PEP.That a possible exposure that already happened is handled by PEP, which must be started as soon as possible and within 72 hours and is taken as a 28-day course for emergencies, distinct from ongoing prevention with PrEP.. PEP is a 28-day course meant for emergencies, and the clock is real: after 72 hours it is no longer offered for that exposure 4Ref 4Centers for Disease Control and Prevention (2024).Clinical Guidance for PEP.That a possible exposure that already happened is handled by PEP, which must be started as soon as possible and within 72 hours and is taken as a 28-day course for emergencies, distinct from ongoing prevention with PrEP..

The two fit together over a life. Someone who keeps needing PEP is usually someone for whom ongoing PrEP makes more sense, and clinicians routinely help people move from an emergency course straight onto steady prevention once the 28 days are done. If you are reading this because something already happened, the honest next step is to be seen today — not to start a pill you happen to have at home. Getting the timing right is the whole game here, and it is measured in hours, not days.

Starting PrEP and staying on it

Starting PrEP begins with confirming you do not already have HIV, because PrEP is the wrong regimen for someone who is positive — starting it with undiagnosed HIV can lead to drug resistance. From there the guideline builds in regular follow-up — repeat HIV testing and lab checks on a set schedule — so that PrEP stays both safe and effective over months and years 2Ref 2Centers for Disease Control and Prevention / US Public Health Service (2021).Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2021 Update: A Clinical Practice Guideline.That the U.S. PrEP guideline asks providers to inform all sexually active adolescents and adults about PrEP and to match the option to the person, and that prescribing PrEP includes baseline confirmation of HIV status and ongoing testing and monitoring.. It is designed to be monitored, not started and forgotten.

Those follow-up visits do double duty. They confirm you are still HIV-negative, check that the medicine is not straining your kidneys, and are a natural moment to screen for other STIs. Side effects, when they happen, are usually mild and early, and there is more to read on the specific PrEP side effects to expect. Stopping is its own small procedure rather than simply quitting: because protection fades once the medicine clears the body, coming off PrEP the right way means planning the timing with a clinician, especially if there is any chance of a recent exposure. Neither starting nor stopping is meant to be done in the dark.

When a partner is living with HIV

If your partner is the reason you are considering PrEP, one fact reshapes the whole decision: a person with HIV who takes their treatment and keeps an undetectable viral load has effectively no risk of passing HIV to a partner through sex — the principle summed up as undetectable equals untransmittable 5Ref 5Centers for Disease Control and Prevention (2024).Undetectable = Untransmittable.That a person with HIV who takes antiretroviral therapy and maintains an undetectable viral load has effectively no risk of sexually transmitting HIV to a partner (undetectable equals untransmittable).. an undetectable partner is not a transmission risk during sex 5Ref 5Centers for Disease Control and Prevention (2024).Undetectable = Untransmittable.That a person with HIV who takes antiretroviral therapy and maintains an undetectable viral load has effectively no risk of sexually transmitting HIV to a partner (undetectable equals untransmittable)..

That does not make PrEP pointless in every serodifferent couple. People choose PrEP for reassurance, for stretches when a partner's viral load is not yet confirmed undetectable, or for exposures outside the relationship. But it reframes PrEP as one option among several rather than a necessity, and it is worth understanding PrEP when your partner is HIV positive as its own situation. Here, more than anywhere, the right answer is personal — which is exactly why all three PrEP options exist.