Doxycycline
Capsule or tablet
Quick Summary
Doxycycline works against a wide range of bacteria and some parasites.
Medical Uses
How it's taken
Swallow with a full glass of water while sitting or standing, and don't lie down for 30 minutes.
Take it for the full course, even if you feel better, unless your doctor tells you otherwise. Don't share antibiotics or keep leftovers.
Your doctor decides the right dose for you and how long to take it.
Your doctor decides the right dose for you. Follow their instructions and the label.
Common Side Effects
Nausea
Take with food if needed.
Sun sensitivity
Use sunscreen.
Heartburn
If the capsule sticks in the throat.
Interactions
Antacids, iron, calcium and dairy
Reduce absorption.
Warfarin
Bleeding risk.
Critical Warnings
Pregnancy and young children
Black Box Warning: Not used in pregnancy or children under 8 (stains teeth).
Sun sensitivity
Avoid strong sunlight.
Severe allergic reaction
Black Box Warning: Swelling of the face or throat, difficulty breathing or a widespread rash: get emergency help.
Antibiotic resistance
Using antibiotics when they aren't needed makes them less effective for everyone.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Doxycycline: drug information(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Doxycycline: antibiotic for bacterial infections(opens in a new tab) · NHS