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New Morning-After Pill for STIs Sparks Debate

By Mara Lafontaine · August 6, 2023

In brief…

  • According to Health officials, DoxyPep can be taken up to 72 hours after sexual activity to prevent sexually transmitted infections (STIs).
  • DoxyPep is a new use for the common antibiotic called doxycycline.
  • STIs have increased by 30% in the last five years, with syphilis rates reaching a 70-year high.
  • Concerns exist that widespread use of DoxyPep could lead to drug-resistant bacteria or superbugs.
  • Other experts say the drug should be widely used at a time of rising STI rates.
A new use for the antibiotic, doxycycline post-exposure prophylaxis, holds promise in the fight against STIs.  National Archives at College Park / Public domain, via Wikimedia Commons

DoxyPep has emerged as the latest and possibly most effective weapon in the war against sexually transmitted infections (STIs). Short hand for doxycycline post-exposure prophylaxis, DoxyPep is gaining a reputation as the ‘morning-after pill’ for STIs. Health officials say it can be taken up to 72 hours after sexual activity to potentially halt bacterial infections, including chlamydia, gonorrhea, and syphilis.

STIs have spiked by approximately 30% over the last five years, with syphilis reaching its highest rates in 70 years, prompting health officials to seek new solutions to an age-old set medical challenge. DoxyPep is not a new antibiotic, but rather a new application of an old one. DoxyPep is a single dose of the antibiotic doxycycline, which is commonly used to prevent Lyme disease, malaria, and long-term acne. 

Fenit Nirappil, Washington Post health and science reporter, told PBS that DoxyPep is currently only recommended for communities of gay men and transgender women - groups that see higher rates of STIs due to smaller dating pools. As a result, the drug has been limited to the communities most vulnerable to STIs due to concerns that regular use of the antibiotic could accelerate the evolution of bacteria, leading to new superbugs and diminishing the antibiotics’ longterm effectiveness against STIs. 

Despite those concerns, some health experts argue that doxycycline is being held to an unfair standard and should be made available for wide use given the rapid growth of STIs.

In any event, DoxyPep has emerged as a powerful new-old tool for fighting sexually transmitted infections.