Can I take Calcium and Doxycycline together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
- Audio Version
- Add to preferred sources on Google
Taking calcium at the same time as doxycycline can stop the antibiotic from working properly. The calcium attaches to the medicine in your stomach, which prevents your body from absorbing it into your bloodstream. This means the infection you are treating might not clear up as it should.
Why this happens
This is an absorption issue called 'chelation'. Calcium binds to the doxycycline molecules in the digestive tract to form a large complex that the body cannot absorb.
What you should do
You should separate the doses of these two substances. Take your doxycycline at least 2 hours before or 3 hours after consuming calcium-rich foods (like milk, cheese, or yoghurt) or calcium supplements.
Important precautions
Photosensitivity
Doxycycline makes your skin much more sensitive to sunlight. You will burn more easily; avoid sunbeds and use high-factor sunscreen even on cloudy days.
Oesophageal irritation
To prevent painful throat irritation or ulcers, swallow doxycycline with a full glass of water while sitting or standing. Do not lie down for at least 30 minutes after taking it.
Food and drink warnings
Alcohol
Chronic or heavy drinking can speed up the removal of doxycycline from your body, making the antibiotic less effective. It is best to avoid or limit alcohol during your treatment.
Caffeine (coffee, tea, cola)
High amounts of caffeine can slightly interfere with how your body absorbs calcium and may increase the amount of calcium lost in your urine. Try to limit caffeine intake or have it at a different time than your supplement.
High-fibre foods (bran, whole grains) and Spinach/Rhubarb
Foods very high in phytic acid (grains) or oxalic acid (spinach, rhubarb) can bind to calcium and reduce its absorption. Avoid taking your calcium supplement at the same time as a very high-fibre meal.
Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
Patient picks for Drug interactions

Drug interactions checker
Can I take Guanfacine and Tizanidine together?
Taking these two medicines together can cause your blood pressure to drop too low and make you feel very sleepy or dizzy. You may feel faint, lightheaded, or even pass out, especially when standing up quickly. It can also significantly slow your heart rate.

Drug interactions checker
Can I take Lisinopril and Potassium together?
Taking lisinopril and potassium supplements together can cause the levels of potassium in your blood to become dangerously high (a condition called hyperkalaemia). While your body needs potassium for your heart and muscles to work, too much of it can lead to serious heart rhythm problems or even cause the heart to stop. Symptoms of high potassium can include muscle weakness, tingling sensations, or palpitations, but often there are no symptoms until the level is very high.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Article also available in English, German, Spanish, French, Italian, Portuguese, Hindi, Hebrew, Arabic, and Swedish.
25 Jan 2026 | Originally published

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.
More in drug interactions checker
- Can I take Alcohol and Candesartan together?
- Can I take Amitriptyline and Lactulose together?
- Can I take Amitriptyline and Paracetamol together?
- Can I take Amitriptyline and Ropinirole together?
- Can I take Anastrozole and Omeprazole together?
- Can I take Atorvastatin and Chaga together?
- Can I take Benylin dry coughs and Clozapine together?
- Can I take Candesartan and Chondroitin together?
- Can I take Dextromethorphan cough medicines and Sertraline together?
- Can I take Ezetimibe and Magnesium together?
- Can I take Folic acid and Oestrogel pump-pack together?
- Can I take Furosemide and Strivit D3 together?
- Can I take Iron and Levothyroxine together?
- Can I take Lercanidipine and Levothyroxine together?
- Can I take Maitake and Royal sun together?
- Can I take Morphine and Paracetamol together?
- Can I take Nikethamide and Venlafaxine together?
- Can I take Sildenafil and Losartan together?
- Can I take Simvastatin and Venlafaxine together?