This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Doxy-PEP is a prevention option that some people in Miami discuss with a clinician. The name stands for doxycycline post-exposure prophylaxis. You will also see it written as doxypep or doxy pep.

The idea is simple. A person takes an antibiotic after sex to lower the chance of certain bacterial infections. The details matter, though, because it only works for some infections and some groups of people.

This guide covers what the CDC says, how the medicine works at a general level, what the safety questions are, and what is known about getting it in Miami.

What doxy-PEP is

Doxy-PEP means taking doxycycline after condomless sex, as a clinician directs, to reduce the chance of bacterial STIs. It is not a vaccine. It is not a replacement for testing.

It is prescription only. A licensed clinician decides whether it fits your situation, writes the prescription and explains how to use it. This article does not cover dosing, and no web page should be used in place of that conversation.

The CDC published its clinical guidance on doxy-PEP in 2024, in its Morbidity and Mortality Weekly Report. That guidance is the main source for this page, along with the CDC STI Treatment Guidelines (2021).

The science: what doxycycline is

Doxycycline is a semisynthetic antibiotic in the tetracycline class. It comes from a family of compounds first found in soil bacteria. Chemists later modified the original structure to make a medicine that is absorbed well and stays active in the body longer.

The active compound is doxycycline itself. Pharmacies stock it as different salt forms, such as hyclate or monohydrate. Those names describe how the same active compound is packaged. They are not different drugs.

Doxycycline works by blocking the part of a bacterial cell that builds proteins. It does this by binding to the bacterial ribosome. Without those proteins, bacteria cannot grow and multiply. Human cells build proteins differently, which is part of why the medicine can be used safely in most people.

That mechanism also explains the limits. Doxycycline acts on bacteria. It has no effect on viruses, so it cannot work against HIV, herpes or HPV.

What research suggests

The CDC's 2024 guidance reviewed several clinical trials. Here is how those findings are best described.

Research suggests doxy-PEP lowered new cases of syphilis and chlamydia in the groups studied.
The CDC review found a smaller reduction for gonorrhea than for chlamydia and syphilis.
The trials with the clearest results enrolled gay, bisexual and other men who have sex with men, and transgender women, many of whom had a recent bacterial STI.

These are observations from specific studies. They do not mean the medicine works the same way for everyone, and they do not mean it prevents every infection in the groups studied.

One trial in cisgender women in Kenya did not show a clear benefit, and the CDC says the evidence for cisgender women is not strong enough to make a recommendation. Researchers noted that taking the medicine consistently was a challenge in that study. More research is under way.

Who the CDC recommends it for

The CDC recommends that clinicians discuss doxy-PEP with gay, bisexual and other men who have sex with men, and with transgender women, who have had at least one bacterial STI in the past 12 months. The bacterial STIs counted are syphilis, chlamydia and gonorrhea.

The CDC describes this as a decision made together by the patient and the clinician. It is not a requirement, and no one has to use it.

For other groups, including cisgender women and heterosexual men, the CDC says the evidence is currently insufficient to make a recommendation. A person in one of those groups can still talk with a clinician about their own situation. Clinicians may weigh the question differently case by case.

A clinician is the right person to say whether doxy-PEP fits you. A web page cannot tell you that.

The 72-hour window

The CDC guidance describes doxy-PEP as something taken after condomless oral, vaginal or anal sex. It should be taken as soon as possible and no later than 72 hours after.

That is the CDC's stated window. It is a time limit for the medicine to be useful. It is not a rule about when to get tested.

If you are comparing it with other prevention tools, note that this window is specific to doxy-PEP. HIV PEP, a different treatment, has its own timing and must be started through a clinician quickly. Ask a clinician about both.

What it prevents and what it does not

Based on the CDC's 2024 guidance, doxy-PEP is aimed at three bacterial infections:

Syphilis
Chlamydia
Gonorrhea

It does not prevent:

HIV
Herpes
HPV
Hepatitis B or hepatitis C
Trichomoniasis
Mpox

Doxy-PEP also does not lower the chance of pregnancy. Condoms, vaccines and HIV PrEP (pre-exposure prophylaxis) address different risks. Many people use several tools together, and a clinician can help you sort out which ones match your life.

Safety profile and contraindications

Doxycycline has been prescribed for decades for conditions such as acne and respiratory infections, so its general safety record is well studied. Even so, it is a medicine, and a clinician should review it with you.

Common side effects described in clinical references include stomach upset or nausea. The medicine can also make skin more sensitive to sun, which matters in Miami. It can irritate the esophagus if it is not taken with enough water. Your clinician and pharmacist can explain how to reduce these effects.

Some people should not take doxycycline, or need extra review. Pregnancy is one example, because tetracycline-class antibiotics are generally avoided during pregnancy. Allergies to the drug class, other medicines you take and certain health conditions are also part of the conversation.

Tell the clinician what else you take, including supplements, because some products can interfere with how doxycycline is absorbed.

The resistance question

Whenever an antibiotic is used more often, bacteria can adapt. This is called antimicrobial resistance, and it is the main public health concern about doxy-PEP.

The CDC's guidance raises two points:

Some gonorrhea strains already carry resistance to tetracycline-class drugs, which may help explain the weaker results for gonorrhea.
Wider use of doxycycline could, over time, encourage resistance in other bacteria, such as Staphylococcus aureus or the bacteria behind other infections.

Because of this, the CDC asks clinicians to keep monitoring. It also advises regular STI testing for people using doxy-PEP, with a typical check-in about every three months. Testing remains useful because doxy-PEP can lower risk but does not remove it, and because an infection that is found early can be treated.

Chlamydia, gonorrhea and syphilis are curable with treatment from a clinician. HIV and herpes are not curable, but both are treatable and manageable.

Sourcing and quality: what to look for

For a prescription medicine, quality comes mostly from the system around it. These are the indicators worth looking for.

A licensed prescriber. The medicine should come from a clinician who knows your health history and has talked through the risks.
A licensed pharmacy. A pharmacy will label the medicine with your name and counsel you on side effects and interactions.
Follow-up testing. A prescriber who arranges regular STI testing is following the CDC's approach.
Clear information. A good clinic explains what the medicine does not cover.

Antibiotics bought without a prescription or from unverified sources may not contain what the label says, and no one will be monitoring you. A clinician can usually offer a safer route.

Doxy-PEP and Miami

Miami-Dade has higher rates of several bacterial STIs than Florida as a whole. According to FLHealthCHARTS, from the Florida Department of Health, in 2025 the county reported:

Chlamydia: 471.5 cases per 100,000 people, compared with 410.8 statewide.
Gonorrhea: 250.5 cases per 100,000, compared with 156.5 statewide.
Infectious (primary and secondary) syphilis: 16.8 cases per 100,000, compared with 12.4 statewide.

These numbers describe a community, not any one person. They are one reason local clinicians often bring up prevention options and regular testing.

Do Miami clinics offer doxy-PEP?

We could not confirm a specific Miami clinic that prescribes doxy-PEP. The Florida Department of Health in Miami-Dade County lists low or no-cost testing for chlamydia, gonorrhea, syphilis and HIV on its STI clinic page. That page does not say whether doxy-PEP is prescribed there.

The Thrivelines page from Pridelines, an LGBTQ+ community center in Miami Beach, shows a DoxyPEP option. The page describes it as navigation to outside prescribers and pharmacy partners, not on-site prescribing. The same page says new clinics are slated to open in October 2026, so confirm what is available before you go.

Care Resource, Borinquen Medical Centers, Jessie Trice Community Health System and the University of Miami's Rapid Access Wellness Clinic list PrEP services. None of the pages we reviewed mention doxy-PEP. It is reasonable to call and ask, since services change.

The Florida Department of Health in Miami-Dade County also publishes a locator for PrEP and nPEP providers. Those providers work in the same prevention space, and some may be able to discuss doxy-PEP or point you to someone who can.

Start with testing

Whether or not you are considering doxy-PEP, testing is the step that gives you real information. A clinician or a test can tell you your status. A web page cannot.

Free and low-cost options exist in the city. The full list of Miami testing locations and costs has the details. Here are a few that are relevant to this topic.

Location	What is published
Health District Center (STI clinic), 1350 NW 14th St., Suite 350, Miami	Run by the Florida Department of Health in Miami-Dade County. Low or no-cost testing for chlamydia, gonorrhea, syphilis and HIV. Monday to Friday, 8 a.m. to 3:30 p.m., closing at noon on the 1st and 3rd Fridays. Call 305-575-3800 to schedule.
West Perrine Health Center (STI clinic), 18255 Homestead Ave., Miami	Same health department program. Tuesday, Thursday and Friday, 8 a.m. to 3:30 p.m., closing at noon on 3rd Fridays. Call 305-575-3800.
Care Resource, 3510 Biscayne Blvd., Miami	CDC GetTested lists free HIV and STI testing, with no appointment required. Testing hours listed as Monday to Friday, 8:15 a.m. to 4:30 p.m. Sliding fee scale for people without insurance. Call 305-576-1234.
Borinquen Medical Centers, 3601 Federal Hwy, Miami	CDC GetTested lists HIV and STI tests as free, with no appointment required. Accepts insurance and offers a sliding scale. Call 305-576-6611.

Hours can change, so check with the clinic before you go. The health department clinic page does not state a walk-in policy, so call ahead.

You can also use the CDC's GetTested locator to find other nearby testing sites. For HIV testing questions, the health department lists a line at 786-792-5269. The Florida Department of Health in Miami-Dade County also offers a free HIV home test kit for county residents.

Privacy and age

Florida Statute 384.30 says any minor may consent to examination and treatment for sexually transmissible diseases. The statute also says that care is confidential and cannot be disclosed indirectly, for example by billing a parent or guardian. That applies to the health department, licensed physicians and qualifying health facilities.

Questions to bring to a clinician

Does my history make doxy-PEP a good fit, based on the CDC's 2024 guidance?
Is it safe with my other medicines, my health conditions and my plans for pregnancy?
How often should I be tested while using it?
Should I also talk about HIV PrEP, vaccines for hepatitis A, hepatitis B, HPV and mpox, and condoms?
Where can I fill the prescription in Miami?

There is no judgment in any of these questions. Clinics hear them every day, and asking is a normal part of looking after your health.

Key takeaways

Doxy-PEP is a prescription-only option the CDC recommends discussing with gay, bisexual and other men who have sex with men, and with transgender women, who had a bacterial STI in the past 12 months.
The CDC describes use as soon as possible and within 72 hours after condomless sex.
It is aimed at syphilis, chlamydia and gonorrhea. It does not prevent HIV, herpes, HPV or other infections.
Antibiotic resistance is a real concern, which is why regular testing is part of the plan.
We could not confirm which Miami clinics prescribe it, so ask the clinic or the health department directly.

Doxy-PEP in Miami: Who It Is For and How to Get It