Doxycycline
Also known as: Vibramycin
What it's for
Doxycycline is an antibiotic that treats many infections including chest infections, skin infections, sexually transmitted infections, and acne. It also prevents malaria.
Comes as: Capsules or tablets
How to take it
- Adults: Usually 100mg once or twice a day.
- Swallow whole with plenty of water while sitting or standing.
- Take with food to reduce stomach upset.
- Finish the full course even if you feel better.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Feeling sick or stomach pain
- Diarrhoea
- Skin becoming more sensitive to sunlight
The leaflet inside the packet lists all known side effects.
Important safety points
- Stay out of strong sunlight and do not use sunbeds
- Do not take with antacids, iron, or calcium supplements (take 2-3 hours apart)
- Can reduce the effectiveness of the contraceptive pill
- Not suitable during pregnancy or for children under 12
Get medical help urgently if…
- You have severe diarrhoea or blood in your stool
- You have a severe skin reaction or blistering
- You have difficulty swallowing or severe throat pain
- You have swelling of your face, lips, or tongue
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.