DoxyPEP and the Interaction with other Drugs

DoxyPEP, utilizing Doxycycline as a preventive measure against sexually transmitted infections (STIs), requires careful consideration of its interactions with other medications for effective treatment. We dive into key interactions, emphasizing the importance of consulting healthcare professionals for personalized guidance. From maintaining regular sexual health routines to avoiding interference with absorption, comprehensive understanding ensures optimal benefits while using DoxyPEP.
February 19, 2024

DoxyPEP stands for the use of Doxycycline as a preventive measure against sexually transmitted infections (STIs). As with any medication, it is very important to be aware to how DoxyPEP interacts with other medications to ensure an effective treatment. Whats important and what should be avoided? We’re here to clarify.

Disclaimer: Please note that this information is provided for general informational purposes only and is not a substitute for professional medical advice or consultation. Each individual's health situation is unique, and it is important to seek the guidance of a qualified healthcare provider for any questions or decisions regarding the use of DoxyPEP or any other medical treatments. If you are considering DoxyPEP for yourself, we recommend contacting your health practitioner or finding one through Every Health for personalized advice and care.

Maintaining Regular Sexual and Reproductive Health Routine

When incorporating DoxyPEP into your routine, it's essential to maintain your regular sexual and reproductive health practices. This includes adhering to your usual HIV medication (if applicable), following the recommended dosing of HIV PrEP (daily or event-based), using condoms, continuing with regular contraceptives, and getting tested for STIs every three to six months. These practices complement the effectiveness of DoxyPEP in preventing STIs.

Sexual health protection is only as good as its building blocks replacing one by another doesn’t make it better combining the parts fitting to the cause is always the better choice.

Interaction with Hormones and Emergency Contraception

Doxycycline, the active ingredient in DoxyPEP, does not interact with hormones typically taken for hormonal replacement therapy or contraception. However, it's crucial to be aware that vomiting or diarrhea can reduce the effectiveness of contraceptives, especially emergency contraception. In such cases, alternative methods or additional precautions may be necessary.

Check for Drug Interactions

It's essential to be vigilant about potential interactions between DoxyPEP and other medications you may be taking. Before starting DoxyPEP, consult with healthcare professionals or check your medications for any drug interactions. Some medications may increase or decrease the effect of other medications and Doxycycline as well in particular:

  • Stomach remedies (antacids such as Renni, Talcid, Gaviscon)
  • Other antibiotics such as Rifampicin or Penicillins
  • Acne medications containing Vitamin A, such as Isotretinoin
  • Some medication for preventing blood clots
  • Medications for epilepsy such as Phenytoin or Carbamazepine
  • Ciclosporin, an immunosuppressive medication

Avoiding Interference with Absorption

After taking a dose of DoxyPEP, it's recommended to avoid ingesting dairy products, calcium supplements, antacids (indigestion remedies), or multivitamins for at least 4 hours. These substances build  strong complexes with Doxycyline that reduce the absorption in the intestines, potentially compromising its effectiveness. Adhering to this guideline ensures optimal absorption and the intended protective benefits of DoxyPEP.

The more medications and supplements you combine, the less you know if you're achieving what you intend; splitting your intake over time is often a good idea.

Consultation with Healthcare Professionals

Individual responses to drug interactions can vary, emphasizing the importance of consulting healthcare professionals. If there are concerns about potential interactions or if you experience any adverse effects, seek guidance promptly. Healthcare providers can offer personalized advice based on your medical history and specific circumstances.


Understanding the interaction of DoxyPEP with other drugs and considering various factors is crucial for users seeking effective STI prevention. By incorporating DoxyPEP into a comprehensive sexual health routine and being aware of potential interactions, individuals can maximize the benefits of this preventive measure while ensuring overall well-being. Open communication with healthcare professionals remains key to a safe and informed experience with DoxyPEP.