Can you take medication while fasting?

Does a pill break a fast?

A tablet or capsule taken with water has no meaningful calories. Syrups, chewables, fizzy tablets and gummies can contain sugar, so check the leaflet or ask your pharmacist. Either way, if a medicine is prescribed, take it as prescribed: it's the fast that should adapt, not the medicine.

Some medicines need food, others an empty stomach

Some medicines are gentler on the stomach, or work as intended, only with a meal. The NHS advises taking ibuprofen ideally with or after food, for example ². Others are the opposite: levothyroxine, for an underactive thyroid, is best taken 30 to 60 minutes before your first meal of the day or any drink with caffeine, such as tea or coffee ³. That one fits a fasting morning well, as long as your black coffee waits.

If a medicine must be taken with food, build your eating window around it, not the other way round. Take it with your first or last meal, or choose a plan whose window covers your doses. A gentle plan such as 14:10 is a perfectly good choice.

Diabetes and blood pressure medication need a plan

A review written for doctors who look after people with diabetes sorts medicines by how risky they are on a fast ¹. These are decisions for your care team, not for an app, but it helps to know why they matter.

Medicine	Why fasting matters
Insulin, sulfonylureas	Blood sugar can fall dangerously low when you skip meals; doses often need lowering, with regular glucose checks 1
Metformin	Low risk of lows; usually continued 1
SGLT2 inhibitors	You pass more water; they may be paused on fasting days if you drink less 1
Diuretics and blood pressure medicines	Fasting can lower fluid intake and blood pressure; doses sometimes need reducing 1
GLP-1 medicines such as semaglutide	Both cut how much you eat; see our GLP-1 guide
Medicines taken with food, such as ibuprofen	Take them with a meal in your eating window 2

What to ask your doctor

Fasting Tracker doesn't know your medication and doesn't replace your doctor's advice. It can help you keep to the hours you've agreed, with a reminder an hour before your goal and another when your eating window is closing.

Sources

1. Grajower MM, Horne BD. Clinical Management of Intermittent Fasting in Patients with Diabetes Mellitus. Nutrients. 2019;11(4):873. doi.org/10.3390/nu11040873
2. NHS. How and when to take ibuprofen (ibuprofen for adults). www.nhs.uk/medicines/ibuprofen-for-adults/how-and-when-to-take-ibuprofen/
3. NHS. Levothyroxine: medicine to treat an underactive thyroid. www.nhs.uk/medicines/levothyroxine/