What are the side effects of doxycycline?

It is important to tell your health professional about any medicines you may be taking, or if you have any current illness, allergies or long-term health conditions. This will help them decide if doxycycline is suitable for you.

Side effects of doxycycline

(1 to 10 in 100 people)
(fewer than 1 in 100 people)
(fewer than 1 in 1000 people at high doses)
Teeth discolouration
Tooth enamel does not form properly (increasing the chance of cavities forming)
Reduced bone growth (in children younger than 8 years)
Sensitivity to light (depends on dose of doxycycline and amount of sun exposure; see below)
Bone deformities
Thrush (candida infection) and other fungal infections
Stomatitis (swelling of the lining of the mouth including cheeks, gums, tongue, lips, roof or floor of the mouth)
Fingernail, toenail discolouration or loosening from nailbed after exposure to sunlight (photo-onycholysis)
Ulcers in oesophagus if tablets not taken correctly
Allergic reactions
Clostridium difficile-associated disease
Liver abnormalities (e.g. hepatitis)
Allergic reactions (see below)
Worsened symptoms of systemic lupus erythematosus (autoimmune disorder affecting skin, joints, kidneys, brain, etc.)
Note: this is not a complete list of all the possible side effects of doxycycline.

Skin sensitivity with doxycycline

Doxycycline can cause your skin to be more sensitive to sunlight than normal. If your skin is exposed to sunlight, you may develop a rash, itching, redness and sunburn.

If you will be spending time outside, particularly between 10am and 3pm, make sure you protect your skin by wearing sunscreen (factor 30 or higher), and wear a hat and protective clothing.

Antibiotics and allergic reactions

Some people experience an allergic reaction to doxycycline or other antibiotics. This is due to an over-reaction of their immune system to the antibiotic.

Symptoms of an allergic reaction can include:

  • hives (large, red raised areas on the skin)
  • swollen lips, tongue or mouth
  • fever (a temperature of 38.5°C or higher)
  • breathing problems
  • fainting.

Seek medical advice if you experience any of these symptoms while you are taking an antibiotic.

It is not known why this happens to some people and not others, but it may mean that you will have to avoid taking doxycycline in the future. There are other types of antibiotics that don’t cause this reaction that will be suitable for you.

Read more about the common side effects of antibiotics.

Who can I ask about side effects?

If you’re concerned that you or someone in your care may have had side effects related to a medicine, seek medical advice. People with questions about their medicines or seeking general information about side effects can also call the NPS Medicines Line on 1300 633 424 (Monday-Friday, 9am-5pm AEST). To report possible side effects call the Adverse Medicine Events (AME) line on 1300 134 237 from anywhere in Australia (Monday–Friday, 9am–5pm AEST).

  • Rossi S, ed. Australian Medicines Handbook [online]. Adelaide: AMH, July 2012.
  • Sweetman S, ed. Martindale: The complete drug reference [online]. London: Pharmaceutical Press (accessed 18 October 2011).
  • Antibiotic Expert Group. Therapeutic Guidelines: Antibiotic version 14; Doxycycline. Melbourne: Therapeutic Guidelines Limited, 2012 (accessed 27 March 2012).