Doxy-PEP (Doxycycline Post-Exposure Prophylaxis) is a new way to prevent certain sexually transmitted infections including Syphilis, Gonorrhea, and Chlamydia. We’ve heard questions from our community about Doxy-PEP and thought it would be important to raise awareness and share expert information about it.   

AFC’s Chief Officer of External Relations, Edward Wagner, recently discussed with India Willis, MPH, MSN, FNP-BC, an AFC Associate Board Member and Advanced Practice Nurse at Ann & Robert H. Lurie Children’s Hospital Chicago, this exciting new STI prevention tool. 

Edward Wagner: Thank you so much, India, for your expertise. Here are some questions that I have, and that I’ve received from others, about Doxy-PEP: 

What exactly is Doxy-PEP? 

India Willis, MPH, MSN, FNP-BC: Doxycycline Post-Exposure Prophylaxis (Doxy-PEP) is an antibiotic used after sex, to prevent sexually transmitted infections. After having sex, taking the antibiotic doxycycline can help prevent getting certain infections, like syphilis and chlamydia. Studies suggest it’s especially effective for transgender women and men who have sex with men, reducing the risk by about two-thirds.  

What STIs does Doxy-PEP help prevent? 

Doxy-PEP helps reduce the risk of Syphilis, Gonorrhea, and Chlamydia. 

Who is Doxy-PEP for? 

Doxy-PEP can be especially effective for transwomen and gay, bisexual, or other men who have sex with men. 

What is the criteria to receive Doxy-PEP? 

In order to be prescribed Doxy-PEP, you should have been diagnosed with one of these STIs in the past 12 months. 

Is there any other reason you can be prescribed it? 

Clinicians may prescribe Doxy-PEP for those with multiple sexual partners, even without recent STIs, based on perceived risk. 

What are the limitations of Doxy-PEP? Or, put another way, what does it not do? 

As an antibiotic, Doxy-PEP does not prevent HIV, Monkeypox (Mpox), or other viral infections. 

How does it work?  

Doxy-PEP works to prevent bacterial STIs by tackling the infection before symptoms show up or it is passed to others. 

When do you take it? 

For optimal effectiveness, take two 100 mg doxycycline pills within 24 hours, but make sure it’s done no later than 72 hours after condomless sex. It works best when taken early, within the first 24 hours. 

How effective is Doxy-PEP? 

In various studies, Doxy-PEP demonstrated a risk reduction of approximately 55-60% for gonorrhea and decreased the chances of developing chlamydia and syphilis by about 80% or more. 

Are there side effects we should be aware of?   

Doxy-PEP might cause an upset stomach and sun sensitivity. For those with fair skin or in sunny climates, sunscreen is a good ally. Occasionally, an allergic reaction or rash can occur. In rare cases, more serious side effects like bad headaches or vision changes can happen. Also, changes in hearing and vision can be signs of syphilis. If that occurs, talk to your healthcare provider ASAP!  

Are there ways to minimize side effects, like the upset stomach? 

If Doxycycline upsets your stomach, taking it with food might help. Take it with a cup of water and food to decrease nausea and headaches 

How about the sun sensitivity? 

Some people become more sensitive to the sun with doxycycline, so wearing sunscreen is a must.  

Anything we should avoid if taking Doxy-PEP? 

Steer clear of dairy products, calcium, antacids, or multivitamins 2 hours before or after taking doxycycline.  

Is it ok to take it with HIV PrEP?

Yes! It is safe to take PrEP for HIV and Doxy-PEP at the same time. 

Where can I go to access Doxy-PEP? 

To get Doxy-PEP, you’ll need a prescription, so have a chat with a health care provider. You don’t necessarily have to visit your primary care provider; sexual health clinics are great options. They offer services like HIV prevention, STI testing, Mpox vaccination, and often provide Doxy-PEP as well. To find a clinic that offers Doxy-PEP, contact the HIV Resource Hub at 1-844-HUB-4040 or hivhub.org. 

What if someone has ongoing condomless sex? How often can one use Doxy-PEP? 

If you engage in sex again within 24 hours of taking doxycycline, go ahead and take another dose 24 hours after your last one. It’s okay to take doxycycline daily when having condomless sex, but remember not to exceed two 100 mg pills (200 mg) within a 24-hour period. 

Is it covered by insurance? If so, how many times can it be covered? 

Some clinics offer Doxy-PEP for free. You can reach out to the HIV Resource Hub for help getting Doxy-PEP – visit hivhub.org or by calling 1-844-HUB-4040. Even if you need to buy it, it’s usually affordable, and insurance often covers it. 

What about antibiotic resistance? 

Good question. Doxy-PEP is a bit of a newcomer, so there’s ongoing exploration into its effects. We’re still figuring out how it might impact the “good” bacteria in the gut, the ones hanging out on our skin (like staph), and if there’s a chance of STIs, like gonorrhea, developing resistance. 

Good news so far: Chlamydia and syphilis do not seem to be developing a resistance to doxycycline, even though it’s been a common antibiotic for ages. 

For those on Doxy-PEP, there’s been no alarming data suggesting increased drug resistance in the patients tracked for about a year. Still, scientists are keeping a close eye on it, just to be safe. 

How will Doxy-PEP impact STI rates? 

Scientists are optimistic that providing Doxy-PEP could help tackle the growing rates of STIs. In 2021 alone, over 2.5 million cases were diagnosed in the U.S. It’s a proactive approach to addressing a significant health concern. 

What are we still learning about with Doxy-PEP? 

A few things! First, the effect on intestinal bacteria. We’re still figuring out if Doxy-PEP impacts the “good” bacteria in our intestines. Also, it’s under investigation whether Doxy-PEP influences the bacteria on our skin (like staph) and if it could lead to resistance. And, we’re monitoring signs of resistance in STIs. Thankfully, although doxycycline has been around for decades, chlamydia and syphilis show no resistance to it. About 25% of gonorrhea in the U.S. is already resistant to doxycycline, so Doxy-PEP might not be effective against these strains. Studies, including the Doxy-PEP study, are ongoing to understand if Doxy-PEP changes resistance in gonorrhea. 

Is there anything else you’d like to share about Doxy-PEP? 

Doxy-PEP is a superhero against certain bacterial infections, but it doesn’t have a shield against HIV or other viral infections like herpes or human papillomavirus (HPV), the culprit behind genital warts. Also, please don’t share your Doxy-PEP – you may not know someone’s sensitivity to the antibiotic. Lastly, If there’s a concern about HIV exposure and you’re not on PrEP, there’s HIV post-exposure prophylaxis (PEP) available, and it’s most effective when taken within three days of condomless sex. 

We hope this Q&A has helped answer your questions about or improve your understanding of Doxy-PEP! AFC would like to thank Associate Board Member India Willis for sharing her expertise with our community.