PrEP for HIV Prevention: Pills vs Shots, Who Should Take It and How to Start
Written by Naurah Gaspard, DNP, FNP-C, FNP-BC · Medically reviewed by Cherlie Joseph, MSN, FNP-BC · Updated November 2026
PrEP (pre-exposure prophylaxis) is a prescription medicine that HIV-negative adults take to prevent HIV. Taken as prescribed, it lowers the risk of getting HIV from sex by about 99%, according to the CDC. Options now include a daily pill, a shot every 2 months, and a shot every 6 months.
In this guide
What PrEP is and how well it works
PrEP is medicine you take before a possible exposure so the virus can't take hold if it enters your body. It is different from PEP (post-exposure prophylaxis), which is a 28-day course started within 72 hours after a possible exposure.
The CDC estimates PrEP reduces the risk of getting HIV from sex by about 99% and from injection drug use by at least 74% when taken as prescribed. The key phrase is "as prescribed": most PrEP failures happen when pills are missed. That is one reason long-acting shots have become popular.
PrEP does not protect against syphilis, gonorrhea, chlamydia or other STIs, so condoms and regular STI testing still matter.
Who should consider PrEP
The CDC recommends that all sexually active adults and teens be told about PrEP, and that anyone who asks for it be able to get it. It is especially worth discussing if, in the past 6 months, you:
- Had anal or vaginal sex without a condom with a partner whose HIV status you don't know or who has HIV that is not suppressed
- Were diagnosed with syphilis, gonorrhea or chlamydia
- Shared needles or injection equipment
- Used PEP more than once
Florida has one of the highest numbers of new HIV diagnoses in the country, so this conversation matters here. You do not need to justify your reasons to ask about PrEP.
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Start a visit →PrEP options compared: pills and shots
| Option | How often | Good to know |
|---|---|---|
| Emtricitabine/tenofovir DF (Truvada and generics) | Pill once daily | Approved for all people at risk through sex or injection drug use; generics are low cost |
| Emtricitabine/tenofovir AF (Descovy) | Pill once daily | Not approved for people at risk through receptive vaginal sex |
| Cabotegravir (Apretude) | Shot every 2 months (after 2 starter shots a month apart) | Given in the buttock at a clinic |
| Lenacapavir (Yeztugo) | Shot every 6 months (after starter shots and pills) | FDA-approved June 2025; added to CDC PrEP recommendations in September 2025 |
Daily pills need about 7 days of daily use to reach full protection for receptive anal sex and about 21 days for receptive vaginal sex and injection drug use. Your provider can explain what applies to you.
How to start PrEP and what the follow-up looks like
Before starting, you need an HIV test to confirm you are HIV-negative, because PrEP alone is not enough to treat HIV and could lead to drug resistance. A typical start includes:
- An HIV test (ideally a lab blood test)
- Kidney function testing for oral PrEP
- Hepatitis B testing, because tenofovir also affects hepatitis B
- STI testing for syphilis, gonorrhea and chlamydia
On oral PrEP, HIV testing is repeated about every 3 months; on Apretude, about every 2 months; on Yeztugo, at each visit. Common side effects of pills are mild nausea, headache or tiredness in the first few weeks. Shots can cause soreness or lumps at the injection site.
In Florida, county health departments offer PrEP services, and many insurance plans cover PrEP with no cost sharing as preventive care. Manufacturer assistance programs exist for the brand-name options. Prices and coverage rules change, so check with your plan or the manufacturer's site.
Symptoms to watch for after an exposure
Early HIV infection can cause a flu-like illness 2 to 4 weeks after exposure: fever, sore throat, rash, swollen glands and body aches. If you have these symptoms while on PrEP or after a missed stretch of doses, get an HIV test right away rather than waiting for your next routine visit. If you had a possible exposure in the last 72 hours and are not on PrEP, ask about PEP the same day.
Get in-person care or call 911 if you have:
- A possible HIV exposure within the last 72 hours and you are not on PrEP (go to an ER or urgent care for same-day PEP)
- High fever with a new rash, severe sore throat or confusion
- Signs of a severe allergic reaction: swelling of the face or throat, trouble breathing
Frequently asked questions
How long does PrEP take to work?
For daily pills, about 7 days of daily doses for receptive anal sex and about 21 days for receptive vaginal sex or injection drug use. Long-acting shots have their own starting schedules, which your provider will review with you.
Can I stop PrEP whenever I want?
You can, but talk with your provider first. Stopping oral PrEP usually means continuing doses for a period after your last possible exposure, and stopping a long-acting shot leaves low drug levels for months, so a plan for HIV testing and another prevention method is important.
Does PrEP protect against other STIs?
No. PrEP only prevents HIV. Condoms help lower the risk of other STIs, and doxy-PEP may be an option for some people to reduce syphilis and chlamydia.
Sources
- CDC: Pre-Exposure Prophylaxis (PrEP)
- CDC: CDC Recommends New Injectable HIV PrEP (2025)
- HIV.gov: Pre-Exposure Prophylaxis
Keep reading
- Doxy-PEP: can doxycycline after sex prevent STIs?
- How soon to get tested after a possible STD exposure
- STD testing online in Florida
- Browse all conditions and treatments A to Z
Have questions about PrEP or HIV testing?
$79 visit, no appointment needed. Adults 18+ in FL, NM, OR and WA.
Start a visit →
Naurah Gaspard, DNP, FNP-C, FNP-BC
Board-certified family nurse practitioner licensed in Florida, New Mexico, Oregon and Washington, caring for adults online at OurTopClinic. Meet our providers.
This article is for general education and is not a substitute for medical advice. Treatment, including any prescription, is decided by a licensed provider after reviewing your health history. OurTopClinic is not for emergencies; if you have a medical emergency, call 911. OurTopClinic serves adults located in Florida, New Mexico, Oregon and Washington. Learn more at ourtopclinic.com.
