Doxycycline belongs to the group of antibiotics known as tetracyclines. Doxycycline is available in various forms, including tablets, capsules, and liquid formulations. We can prescribe doxycycline in capsule form to treat acne and chlamydia.

Find out more about the treatments we offer for acne.

Find out more about the treatment we offer for chlamydia.

Doxycycline is an antibiotic commonly prescribed to treat a variety of infections, including acne and chlamydia. Acne is a common inflammatory skin condition that causes spots on the face, back or chest. Chlamydia is a sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It’s one of the most common STIs in the UK and can affect both men and women.

Chlamydia often has no symptoms. If you’re worried you may have caught it then you can take a simple at-home test to find out and make sure you get treatment as soon as possible if needed.

Find out more about acne.

Find out more about chlamydia.

Doxycycline is an antibiotic. Antibiotics clear up bacterial infections by stopping the bacteria from making the proteins they need to survive. Doxycycline also has an anti-inflammatory effect making it especially useful for treating acne.

Swallow one 100mg capsule once or twice daily according to instructions. We recommend you take doxycycline with plenty of fluid and with food (preferably a full meal). This will help to reduce the risk of stomach-related side effects. It’s important to take the medication in an upright position and avoid lying down for at least 30 minutes after taking. This will help to reduce the risk of stomach-related side effects such as heartburn.

If you’re taking doxycycline for chlamydia, it’s important to complete the full seven-day course of antibiotics and not have sex including vaginal, oral or anal, even with a condom during your treatment, even if any symptoms improve before the course is finished. This ensures that the infection is fully eradicated.

The doxycycline dosage and length of treatment will differ depending on what is being treated. For acne, you take one 100mg capsule every day, usually for three to six months.

For chlamydia, you take one 100mg capsule at two different times a day for seven days. This is the recommended dose of doxycycline when used to fight off the bacteria that causes chlamydia.

If you’re wondering how long doxycycline takes to work, the answer is it starts working against an infection soon after you begin taking it. If you’re taking doxycycline for acne, some people start to see some improvement in as little as two weeks, although it can take six to eight weeks before you see significant improvement.

If you’re taking doxycycline for chlamydia, it may take as little as a few days for symptoms to begin to improve. However, it’s very important that you take your full course of doxycycline antibiotics to make sure that the infection is fully cleared up. For chlamydia, a course of treatment takes seven days, with one 100mg doxycycline capsules taken twice a day.

If you’re still experiencing symptoms after this time, you should talk to your regular GP or attend your local NHS sexual health clinic as soon as possible.

Like with any medicine, people taking doxycycline may experience side effects. Common side effects of doxycycline include headaches, nausea and vomiting.

Doxycycline can also increase skin sensitivity to sunlight (photosensitivity). You should make sure to wear sunscreen and avoid bright sunlight or sunlamps while taking doxycycline.

In rare cases, doxycycline may cause a serious allergic reaction. Stop this medicine and seek immediate medical help if you develop an allergic rash, wheezing, chest tightness or swelling of your tongue or face. Doxycycline can also very occasionally cause ulcers in the oesophagus if taken just before you lie down. Make sure to take doxycycline with plenty of water and food, and 30 minutes before lying down.

Please read the Patient Information Leaflet for full details on taking doxycycline and possible side effects.

Can I take doxycycline if I’m pregnant or breastfeeding? If you’re pregnant, think you might be pregnant or breastfeeding you should not take doxycycline. Doxycycline should not be taken in pregnancy as it’s harmful to the foetus. If you’re sexually active with a man and there’s a chance you might become pregnant, we recommend using effective contraception such as the pill, implant or coil. Please talk to your regular GP or healthcare provider. They’ll be able to suggest an alternative antibiotic.

Does doxycycline contain penicillin? Doxycycline does not contain penicillin. Doxycycline and penicillin are both antibiotics but doxycycline belongs to a different class of antibiotics called tetracyclines. If you have a known allergy to penicillin, it doesn’t mean you’ll also be allergic to doxycycline.

However, you must inform us of any allergies, health conditions or other medicines you’re taking during your online questionnaire so we only prescribe treatment if suitable for you. Doxycycline should not be taken at the same time as certain other medicines.

If you don’t want to take doxycycline to treat moderate to severe inflammatory acne, there are alternative treatments that can help. There are several different types of prescription topical treatments available for your skin in the form of creams and gels. These can be used alone or in combination with an alternative antibiotic tablet. If your acne is mild, it’s best to use topical creams and gels alone to treat your skin.

If you’re a woman between the ages of 16 and 50 we may be able to prescribe a combined oral contraceptive pill which can help to reduce the hormones that can increase acne. If suitable, the oral contraceptive can be taken with a cream or gel that you apply to your skin. To find out more about the alternative treatments we offer for acne, click here.

It’s important to seek and complete a course of treatment as soon as possible once symptoms appear or you get a positive chlamydia test. If you don’t get treated you risk spreading the infection to other partners. If left untreated, chlamydia can cause permanent damage including infertility, pelvic inflammatory disease or inflammation of the testicles.

Your GP might prescribe you a different type of antibiotic if you’re allergic to doxycycline, pregnant or breastfeeding, or get side effects from doxycycline.

If you don’t want to take doxycycline for acne, there are things you can do to improve your skin. Try to avoid the triggers that can make acne worse. Picking and squeezing spots spreads the germs that cause acne and increases inflammation. Oil-based make-up and cosmetics can also block pores and may make your acne worse. Use an unfragranced oil-free cleanser daily to clean your skin but avoid drying out or scrubbing your skin by washing it more than twice a day. If you use a moisturiser, make sure that it’s unfragranced and oil-free or non-comedogenic.

Some medications, including progesterone only methods of contraception such as the progesterone only pill can make acne worse. If you use one of these methods and suffer from acne, you might want to consider other options.

It’s still unclear if diet affects acne but there is some evidence that having a balanced diet may help and you should drink plenty of water.

The most important way to avoid catching chlamydia is to practice safe sex, even when you don’t think that either you or your partners are infected. For more advice on how to practice safe sex, click here.

Doxycycline is not known to have any significant interactions with paracetamol or ibuprofen. Therefore, it’s generally safe to take paracetamol for pain relief while on doxycycline.

It’s okay to have 1-2 drinks occasionally while you’re taking Doxycycline. However, if you’re a heavy, regular drinker, then this may not be the best treatment for you. Alcohol reduces the effectiveness of antibiotics and can increase the risk of side effects such as an upset stomach or dizziness.

If you don’t have any symptoms but are worried you might have been exposed to chlamydia, you can get easy-to-use, at-home STI test kits through Boots Online Doctor. You should also get in touch with any sexual partners you’ve had over the last six months so that they can decide whether to get assessed for a chlamydia infection.

If you know you’ve got chlamydia, even if you don’t have symptoms, and you want to test for another STI, it’s important to get the timing of the test right. To check for chlamydia or gonorrhoea, you need to wait two weeks after having sex with someone. For some other STIs such as HIV you may need to wait longer for the test to provide accurate results.

If you’re experiencing symptoms such as pain when peeing, unusual discharge from the vagina, penis or bottom, a painful tummy, bleeding after sex and bleeding between periods in women or pain and swelling in the testicles in men you should get tested straight away. You may also need additional testing for other STIs. Please see your GP or attend a sexual health clinic for help.

Doxycycline isn’t known to have a direct effect on menstrual cycles. However, some women may experience changes in their menstrual pattern while taking antibiotics due to factors such as stress or illness. If you notice any significant changes or abnormalities in your menstrual cycle, please talk to your regular GP or healthcare provider.

If you need to take oral antibiotics such as doxycycline, you might want to consider consuming foods that help promote the “friendly” bacteria in your gut and protect it from being affected by the antibiotics. Foods that have live bacterial cultures such as kefir, live yoghurt or sauerkraut, as well as a good amount of vegetables and fruit, may prove helpful.

Supplements labelled as ‘probiotic’ may also be of some benefit, but because of the way these products are regulated, it’s difficult to know if they deliver enough live bacteria to the gut to have a real effect. While more research is being done to learn more about this field, it may be better to consume food with live bacterial cultures for now.