How common are doxyPEP side effects?

Because you take doxyPEP only now and then, and only one dose at a time, side effects are usually mild. In the large studies, few people stopped using doxyPEP because of them.

Below you see which side effects are more and less common. The bars show how often they occur compared to each other, not exact percentages.

Nausea or stomach upset
Common
Skin burns faster in the sun
Common
Heartburn or sore throat
Less common
Diarrhoea
Less common
Vaginal thrush
Less common
Allergic reaction
Rare

Indication based on the patient information for doxycycline.

Nausea and stomach upset

Person standing upright taking a tablet with a full glass of water

The most common side effect. You may feel a bit queasy for a few hours after your dose. It helps to:

  • take the tablets with a light meal (no dairy);
  • drink a full glass of water with them;
  • stay upright for at least 30 minutes.

If you throw up shortly after your dose, ask the doctor or a pharmacist whether to take another one.

Sun sensitivity

Doxycycline makes your skin more sensitive to UV light for a few days. You can burn faster than usual, even on a cloudy day. Use sunscreen with a high factor, cover up and skip the sunbed. This matters most in summer, on holiday and at outdoor festivals.

Heartburn or a sore throat

A tablet that gets stuck in your throat can irritate it. That is why you take doxyPEP with plenty of water and do not lie down right after. Pain when swallowing that does not go away within a day is a reason to call a doctor.

Thrush and gut

Antibiotics also affect the good bacteria in your body. Some women get vaginal thrush after doxycycline; treatment is simple and available at the pharmacy. Mild diarrhoea can also happen and usually passes by itself. Read more in doxyPEP for women.

When to call a doctor

Call a doctor if you have severe or bloody diarrhoea, a bad headache with blurred or double vision, or pain when swallowing that does not go away. Call emergency services straight away if your face, lips or throat swell, or you have trouble breathing.

What about long-term use?

Doctors have prescribed doxycycline for decades, sometimes for months in a row, for example for acne. It is a well-known medicine. The main open question with doxyPEP is not your own safety but antibiotic resistance. That is why you only take a dose after a real risk, never more than 200 mg in 24 hours.

Frequently asked questions

What are the most common doxyPEP side effects?
The most common side effects are nausea, an upset stomach and a skin that burns more easily in the sun. They are usually mild and pass within a day or two.
How long do doxyPEP side effects last?
Stomach complaints usually pass within a day. Sun sensitivity can last a few days after a dose.
Can doxyPEP cause a yeast infection?
Yes, like other antibiotics, doxycycline can sometimes cause vaginal thrush. Treatment is simple and available at the pharmacy.
When should I call a doctor about doxyPEP side effects?
Call a doctor if you have severe or bloody diarrhoea, a bad headache with blurred vision, or pain when swallowing that does not go away. Call emergency services straight away if you have swelling of your face or throat or trouble breathing.