Key points at a glance
🦠 Protection against certain STIs
Doxy-PEP can reduce the risk of syphilis and chlamydia.
🚫 No protection against gonorrhoea
Doxycycline is not a reliable treatment for gonorrhoea in Europe.
⚠️ Be aware of the risks
Doxycycline can cause side effects, drug interactions and resistance.
🩺 Seek medical advice
Doxycycline should only be taken on medical advice.
What are Doxy-PEP and Doxy-PrEP?
Doxycycline is an antibiotic. It can be used not only to treat, but also to prevent certain sexually transmitted infections.
This preventive use is known as Doxy-PEP or Doxy-PrEP. It is primarily recommended for people at high risk of STIs, for example those who frequently change sexual partners.
How effective are Doxy-PEP and Doxy-PrEP?
Doxycycline can significantly reduce the risk of syphilis and chlamydia. However, the antibiotic does not provide complete protection.
Doxycycline is not effective against gonorrhoea in Europe. The bacteria causing the infection there are already resistant to the drug. Doxycycline also does not protect against other sexually transmitted infections.
The protective effects demonstrated to date have primarily been identified in studies involving gay and bisexual men, as well as some trans women. The studies predominantly involved people on HIV PrEP or living with HIV, who frequently changed sexual partners and were at very high risk of STIs.
To date, there has been only one study on cis women. That study failed to demonstrate any protective effect. There is also a lack of sufficient data for other groups.
Doxy-PEP and Doxy-PrEP: How to take them
There are two different forms of doxycycline available for preventive use.
- Doxy-PEP: Following sexual contact where there is a risk of transmission, 200 mg of doxycycline should be taken. This should be done within 24 hours. If there has been contact with certain pathogens, the aim is to prevent them from establishing themselves in the body.
- Doxy-PrEP: In this case, doxycycline is taken every day on a long-term basis. This means the body is continuously exposed to the antibiotic. This form has not yet been thoroughly researched and may have serious side effects. The German STI Society expressly advises against long-term doxycycline PrEP.
Doxy-PEP and Doxy-PrEP: Risks
Doxycycline can have significant effects on the body. These include changes to the gut microbiome and increased sensitivity to light. This can lead to skin redness, blisters or sunburn setting in more quickly.
There may also be other risks:
- Resistances: Bacteria can develop resistance to doxycycline. In that case, the antibiotic may no longer be effective even if used in subsequent treatment.
- Interactions: Doxycycline may interact with other medicines.
- Weight gain: If taken over a prolonged period, body weight may increase.
- Pregnancy: Doxycycline may harm an unborn baby.
Frequently asked questions
What are Doxy-PEP and Doxy-PrEP?
In this context, the antibiotic doxycycline is used as a preventative measure against certain sexually transmitted infections. Doxy-PEP is taken following a potential exposure. Doxy-PrEP involves taking the medication daily on a long-term basis.
Which STIs can Doxy-PEP protect against?
Doxycycline can reduce the risk of syphilis and chlamydia. It is not a reliable treatment for gonorrhoea in Europe. Nor does it protect against other sexually transmitted infections.
How is Doxy-PEP taken?
With Doxy-PEP, 200 mg of doxycycline is taken within 24 hours of sexual contact where there is a risk of transmission.
Is Doxy-PrEP recommended?
Long-term daily use has not yet been thoroughly researched and may cause serious side effects. The German Society for Sexually Transmitted Infections (STI) is expressly opposed to Doxy-PrEP.
What are the risks associated with doxycycline?
Possible effects include changes to the gut microbiome, increased sensitivity to light, interactions and resistance. Doxycycline may also harm the unborn child. You should consult a doctor before taking it.
