Superdrug has introduced a £10 antibiotic pill called DoxyPEP, a preventative treatment aimed at reducing the rates of certain bacterial sexually transmitted infections (STIs). The medication, designed to be taken within 72 hours after unprotected sex, has shown potential to lower the risk of syphilis and chlamydia by up to 80 percent.

The rollout follows the publication of the United Kingdom’s first national guidance on DoxyPEP in June by the British Association for Sexual Health and HIV, which focuses on its use in at-risk populations, primarily gay and bisexual men. Despite this step, some experts argue that access to the drug should be broadened across the UK and the United States to increase its preventative impact amid rising STI rates.

The number of STI diagnoses has surged recently, attributed to changing sexual behaviors and the growing challenge of antibiotic resistance. In 2025, approximately 334,000 people in the UK were diagnosed with infections including chlamydia, gonorrhea, and syphilis. Chlamydia remains the most frequently diagnosed STI, accounting for nearly half of cases.

DoxyPEP consists of two 100 mg capsules recommended to be taken as soon as possible within 24 hours following unprotected sex, though it can be administered up to 72 hours later. If multiple instances of unprotected intercourse occur within that timeframe, only a single 100 mg dose is required at the end of the three-day period. The drug is not intended for individuals showing symptoms of an STI, who require diagnostic testing and treatment.

The medication has previously been used within the National Health Service (NHS) to treat these bacterial infections once contracted. Its preventative application, however, marks a new approach in the field of sexual health. According to Dr. Babak Ashrafi, the resident general practitioner at Superdrug Online Doctor, DoxyPEP provides an additional evidence-based option that complements regular STI testing and other preventive measures.

Data supporting the use of DoxyPEP includes a real-world study conducted by the Harvard Pilgrim Health Care Institute in the United States. The study involved over 2,200 participants already using pre-exposure prophylaxis (PrEP) for HIV prevention and showed a 79 percent reduction in chlamydia, an 80 percent reduction in syphilis, and a 12 percent reduction in gonorrhea among users.

While DoxyPEP is currently targeted toward populations at higher risk, health experts emphasize that no single intervention can completely prevent STI transmission. Regular testing and safe sexual practices remain essential components of a comprehensive approach to sexual health. The availability of DoxyPEP at an accessible price point—£10.99 for two capsules and £14.99 for four—is seen by some as a promising tool to help curb the rise in bacterial STI rates.