DoxyPEP is considered safe to use, has few side effects, and does not interact with most medications.

Common, mild side effects can include:

• Nausea
• Headaches
• Mild gastrointestinal issues (acid reflux or upset stomach)

Side effects, and their severity can be reduced by:

• Taking your dose with a meal and a large glass of water. Avoid drinking alcohol at the same time as your dose
• Remain upright (sitting or standing) for 30 minutes after taking your dose to prevent acid reflux
• Doxycycline can make the skin sensitive to sunlight so use sunscreen with a high SPF if you are using DoxyPEP regularly and spend time outdoors
• As more frequent use of doxycycline can disrupt the balance of ‘good’ bacteria in the body , this can affect gut health and increase the likelihood of developing vaginal yeast infections. If you are using doxyPEP regularly, consider taking probiotic supplements to counter the effects on your gut, and speak to your sexual healthcare provider for advice on how to reduce the likelihood of vaginal yeast infections

DoxyPEP is safe to use if you are living with HIV and can be used in combination with your HIV medication. DoxyPEP does not affect the effectiveness of oral contraception, hormone replacement therapy (HRT), or HIV PrEP.