Can I take Fibre supplements and Rybelsus together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking fibre supplements at the same time as Rybelsus may prevent your body from absorbing the medication properly, making it less effective at controlling your blood sugar levels.
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Why this happens
Rybelsus (semaglutide) is a very sensitive tablet that must be absorbed through the stomach lining. Fibre supplements can bulk up the stomach contents and bind to the medication, physically blocking it from being absorbed into your bloodstream.
What you should do
Back to contentsYou must take Rybelsus on an empty stomach when you first wake up with a small sip of plain water (no more than 120ml). Wait at least 30 to 60 minutes before taking your fibre supplement, eating, or taking any other oral medications.
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Important precautions
Back to contentsChoking and intestinal blockage
You must take fibre supplements with a full glass of water (at least 200ml). Taking them without enough liquid can cause the supplement to swell and block your throat or oesophagus, leading to choking or bowel obstruction.
Pancreatitis
Stop using Rybelsus and seek urgent medical help if you develop severe, persistent stomach pain that may radiate to your back, as this can be a sign of an inflamed pancreas.
Diabetic retinopathy - Rybelsus
If you have type 2 diabetes, rapid improvement in blood sugar can temporarily worsen diabetic eye disease. You must report any changes in your vision to your doctor.
Pregnancy
You must stop taking semaglutide at least two months before a planned pregnancy because it may harm an unborn baby.
Drug absorption interference
Fibre can prevent other medicines from being absorbed properly. Take your other medications at least 1 hour before or 2 to 4 hours after taking a fibre supplement.
Food and drink warnings
Back to contentsAlcohol
It is best to avoid or strictly limit alcohol when taking these supplements. Alcohol can contribute to dehydration, which increases the risk of the supplement causing constipation or a bowel blockage.
It is best to avoid or strictly limit alcohol while taking semaglutide. Alcohol can increase the risk of low blood sugar (hypoglycaemia) and may worsen common side effects like nausea, vomiting, and stomach pain. Heavy drinking also increases the risk of pancreatitis, a serious potential side effect of this medicine.
Water and fluids
You must drink plenty of water (at least 200ml per dose) when taking fibre supplements. If you do not drink enough fluid, the supplement can cause a blockage in your intestine or throat.
Food and Drink (Timing)
If you are taking the tablet form (Rybelsus), you must take it on an empty stomach with a small sip of plain water (no more than 120ml). You must wait at least 30 minutes before eating, drinking anything else, or taking other oral medicines. Eating too soon will prevent the medicine from being absorbed properly.
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Using other medicines
Back to contentsTaking 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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Article history
The information on this page is written and peer reviewed by qualified clinicians.
25 Jan 2026 | Originally published

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