Can I take Levothyroxine and Fibre supplements together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking fibre supplements at the same time as levothyroxine can stop your body from absorbing the medicine properly. This means you might not get the full dose of thyroid hormone you need, which could lead to symptoms of an underactive thyroid, such as feeling tired, cold, or gaining weight.
Why this happens
Fibre acts like a sponge in your stomach and intestines. It can bind to the levothyroxine molecules, trapping them and carrying them out of your body before they have a chance to enter your bloodstream.
What you should do
You do not need to stop taking fibre, but you must space them out. Take your levothyroxine on an empty stomach, at least 30 to 60 minutes before breakfast. Wait at least 4 hours after taking your levothyroxine before taking a fibre supplement (like psyllium husk, Fybogel, or methylcellulose).
Food and drink warnings
Caffeine (Coffee)
Coffee can significantly reduce the absorption of levothyroxine. You should wait at least 30 to 60 minutes after taking your tablet before drinking coffee.
Dairy products (Calcium)
Calcium found in milk, cheese, and yoghurt can prevent levothyroxine from being absorbed properly. Leave a gap of at least 4 hours between taking your medicine and consuming large amounts of dairy.
Soya
Soya can interfere with how levothyroxine is absorbed. If you eat or drink a lot of soya (such as soya milk or tofu), you may need a dose adjustment. Consult your doctor if you change the amount of soya in your diet.
Papaya
There is some evidence that eating large amounts of papaya may decrease the effectiveness of levothyroxine.
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.
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