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Common questions about doxycycline

How does doxycycline work?

Doxycycline is from a group of medicines called tetracycline antibiotics. These antibiotics work by killing bacteria by stopping them from making the proteins that they need to survive.

For conditions like rosacea, doxycycline is used to make the skin less inflamed.

When will I feel better?

With most infections, you'll usually feel better within a few days. When you do, it's important to keep taking doxycycline until you finish your medicine. Taking all your medicine will help stop the infection coming back.

What if I do not get better?

If you have rosacea, doxycycline works slowly to treat it. Your doctor will usually review you after 4 to 6 weeks to check how well the medicine is working.

If you're taking doxycycline for any other infection, tell your doctor if you do not start feeling better after 3 days. Also tell them if, at any time, you start to feel worse.

If you are taking doxycycline to prevent malaria, you will not feel any different. Take doxycycline as prescribed, and continue taking it for 4 weeks after leaving the area where there is malaria.

Will it give me thrush?

Some people get a fungal infection called thrush after taking a course of antibiotics like doxycycline. This is because the antibiotics kill the normal harmless bacteria that help protect you against thrush.

If this happens to you, ask your pharmacist or doctor for advice.

Does it stain teeth?

Doxycycline can build up in growing bones and teeth by sticking to calcium – this can stain teeth. Because this only happens in growing bones and teeth, it's not usually given to young children, during pregnancy, or when breastfeeding.

Can I take doxycycline if I'm allergic to penicillin?

Yes, you can take doxycycline if you are allergic to penicillin. They are different types of antibiotic.

I'm taking doxycycline to prevent malaria while in a hot country, is it better to use another medicine so I do not react to sunlight?

Doxycycline has been used successfully in hot countries for many years. The best way to protect yourself against a reaction to sunlight is to be careful when out in the sun – wear clothes that cover you up, a hat and sunglasses. Use a high factor (at least SPF 30) sunscreen or sunblock on your skin.

Speak to your doctor of pharmacist if you have any questions about this.

Will it affect my contraception?

Doxycycline does not affect any type of contraception, including the combined pill and emergency contraception.

However, if doxycycline makes you sick (vomit) or have severe diarrhoea for more than 24 hours, your combined pill may not protect you from pregnancy. Check the pill packet to find out what to do.

Find out more about what to do if you're on the pill and you're being sick or have diarrhoea.

Can I drink alcohol while taking doxycycline?

It's best not to drink alcohol with doxycycline because it can stop it working properly. Speak to your doctor or pharmacist if you have questions about this.

Is there any food or drink I need to avoid?

Apart from avoiding alcohol, you can eat and drink normally while you're taking doxycycline.

Page last reviewed: 19 January 2022
Next review due: 19 January 2025