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Can you fast in Ramadan on Mounjaro or Wegovy?

Dose timing, Wegovy tablets, hypos, water and Iftar meals: what UK and international Ramadan guidance says about GLP-1 medicines.

GLP Guidebook teamPublished 12 Oct 202610 min read20 sourcesWritten from published sources

Written for the UK. Reading from India? India version

The short answer

Many people do, with planning. UK pharmacy advice, citing IDF-DAR, is to finish dose increases 4 to 6 weeks before Ramadan. Injected GLP-1s do not break the fast, but Wegovy tablets need an 8-hour fast and a 30-minute wait. Hypo risk rises mainly with insulin or a sulfonylurea.

Key takeaways

  • Dose increases should be finished at least 4 to 6 weeks before Ramadan, says UK pharmacy advice citing IDF-DAR and a London prescribing committee.1
  • The UK Wegovy tablet label says to take it after at least 8 hours without food, then wait 30 minutes, which has to fit between Iftar and Suhoor.2
  • IDF-DAR says to break the fast if blood sugar falls below 3.9 mmol/L or rises above 16.6 mmol/L, or with signs of dehydration or illness.3
  • A 2025 review of 4 diabetes studies found fewer hypos on GLP‑1s during Ramadan than on comparison medicines, but more nausea and vomiting.4
  • The UK Mounjaro and Ozempic labels allow the weekly injection day to change if at least 3 days pass between two doses.5,6
On this page
  1. What do guidelines say about GLP-1 doses around Ramadan?
  2. Does a weekly injection break the fast?
  3. What about Wegovy tablets during Ramadan?
  4. Who is at risk of low blood sugar during a fast?
  5. Why do water and kidneys matter on a long fast?
  6. What happens with a big Iftar meal?
  7. What do studies of GLP-1s in Ramadan show?
  8. Questions people ask
  9. How we researched this

What do guidelines say about GLP-1 doses around Ramadan?

Finish any dose increases well before Ramadan starts. UK pharmacy advice, citing IDF-DAR and a London prescribing committee, says at least 4 to 6 weeks before.1

Before you go further
  • GLP‑1 medicines are prescription-only in the UK. On the NHS or privately, a healthcare professional has to assess you before a prescription is issued.7
  • The label facts here come from the UK product information (the SmPC, the official label each maker publishes on the electronic Medicines Compendium). Where we use a US or EU label instead, we say so.
  • Fasting decisions are yours, with your prescriber and, if you wish, your religious adviser. This post reports guidance; it does not tell anyone whether to fast.
  • Every risk of these medicines is in Guide 5: Side effects and risks.
  • This post describes labels, guidance and trials. It is not a plan for your treatment, and no dose or brand guarantees any result.

Ramadan lasts 29 or 30 days, with no food or drink from dawn to dusk. Depending on season and place, each day's fast runs from 10 to 20 hours.3 Ramadan follows the lunar calendar, so its dates move each year.3

  • Plan early. IDF-DAR, the main international Ramadan guideline, says people with diabetes should see their healthcare team 6 to 8 weeks before Ramadan.3
  • Doses settled first. A July 2026 article for UK pharmacists says to complete dose increases at least 4 to 6 weeks before Ramadan, so stomach side effects can settle. It says to put off a dose increase if the fast is about to begin.1
  • Not a time to start. A 2025 review notes that guidelines advise against starting a GLP‑1 just before Ramadan, because of stomach side effects.4
  • Settled doses. For liraglutide and other older GLP‑1s, IDF-DAR says no further changes are needed once the dose was settled 2 to 4 weeks before.3 The UK South Asian Health Foundation says GLP‑1s need no dose change and carry a low risk of hypos.8

A 2023 review, summarising IDF-DAR, says people with diabetes on a GLP‑1 should not stop it without speaking to a healthcare professional, even if they fast.9 Stopping and restarting has its own effects, covered in what happens when you stop.

Does a weekly injection break the fast?

The UK pharmacy article says injected GLP‑1s do not invalidate the Islamic fast, citing IDF-DAR. A tablet swallowed in daylight would.1

It adds that you may wish to confirm this with your religious adviser.1 It also notes that obesity and many long-term conditions are recognised grounds for exemption from fasting.1 IDF-DAR says pricking a finger to test blood sugar does not break the fast.3

Changing the injection day. The UK Mounjaro and Ozempic labels allow the weekly day to change, as long as at least 3 days pass between two doses.5,6 The pharmacy article suggests injecting after Iftar may ease nausea, or after Suhoor may help fullness through the day. It says not to change the day and the dose together.1 Your prescriber sets the plan.

What about Wegovy tablets during Ramadan?

They are harder to fit around a fast. The UK label says to take them after at least 8 hours without food, then wait 30 minutes before eating or drinking.2

Wegovy tablets were approved in the UK on 11 June 2026.10 The UK label says to swallow the tablet whole with a sip of water, up to half a glass (120 ml).2 Waiting less than 30 minutes lowers how much is absorbed.2

The UK pharmacy article says the tablet must fit into the overnight eating window, ideally on waking for Suhoor, then a 30-minute wait before eating.1 Where that is too tight, it says an injection or a planned pause may suit better, as an individual decision.1 In a Novo Nordisk-funded study of diabetes tablets, most Ramadan doses were taken at Iftar, unlike the label's morning timing.11 Our post on weight-loss pills in the UK covers the tablets.

Who is at risk of low blood sugar during a fast?

Mainly people with diabetes who also take insulin or a sulfonylurea such as gliclazide. On its own, a GLP‑1 carries a low risk of severe lows.3,5

GLP‑1s raise insulin mainly when blood sugar is high, so IDF-DAR rates the risk of a severe low as low when they are used alone.3 With insulin or a sulfonylurea, the UK Mounjaro label says the risk of a hypo rises.5 The UK pharmacy article lists insulin or sulfonylureas, recent severe hypos, pregnancy and recent ketoacidosis as reasons fasting may be unsafe.1

The South Asian Health Foundation rates people on a GLP‑1 with moderately controlled diabetes as moderate risk. Type 1 diabetes, an HbA1c above 8.5% and pregnancy are high risk.8 HbA1c is your average blood sugar over about 3 months.

When IDF-DAR says to break the fast.
  • Blood sugar below 3.9 mmol/L.
  • Blood sugar above 16.6 mmol/L.
  • Signs of a hypo, high sugar, dehydration or illness.
It says to recheck within an hour if sugar is between 3.9 and 5.0 mmol/L.3 The pharmacy article says Islamic guidance allows breaking the fast to treat a hypo.1

The NHS lists shaking, sweating, a fast heartbeat and confusion among hypo signs.12 It says to treat a low with a sugary drink or glucose tablets, then check again after 10 to 15 minutes.12

Free toolQuestions to take to your pre-Ramadan visit

Builds a printable list for your GP, nurse or pharmacist, including your medicines and fasting plans. No sign-up.

Make my list

Why do water and kidneys matter on a long fast?

Vomiting and diarrhoea are common side effects, and losing fluid while fasting can lead to dehydration. The UK labels warn this can harm the kidneys.5,13

The UK pharmacy article says fasting can add to constipation, dehydration and nutritional gaps on these medicines.1 It suggests 1.5 to 2 litres of sugar-free fluid between Iftar and Suhoor, and less caffeine.1 IDF-DAR says tea, coffee and cola can add to dehydration.3

The NHS lists dark, strong-smelling pee, peeing less, dizziness and a dry mouth as signs of dehydration.14 The pharmacy article says a vomiting bug or fever is itself a reason to break the fast, and that vomiting beyond 24 hours needs review.1

What happens with a big Iftar meal?

Large meals make vomiting more likely on these medicines, and nausea often comes after long gaps without food. A long fast followed by a big meal combines both.15

A 2025 advisory from four US nutrition and obesity societies says nausea "often occurs in the morning or after longer periods without eating". It says vomiting "is more likely to occur with large meals".15 IDF-DAR notes that Iftar meals often run past 1,500 calories and are eaten quickly.3

  • Iftar: IDF-DAR suggests starting with plenty of water and 1 to 3 dates.3 The UK pharmacy article suggests limiting dates to 1 or 2, and limiting fried foods and sweet treats.1
  • Suhoor: it suggests slow-release starchy foods such as oats or brown rice, pulses for protein, and fruit and vegetables against constipation.1
  • Protein: the US advisory says eating protein-rich foods first in a meal can help reach enough protein when appetite is low.15

What do studies of GLP-1s in Ramadan show?

The studies are few and mostly in diabetes. They found fewer hypos than with older diabetes medicines, but more stomach side effects.4

  • A 2025 review pooled 4 studies of 754 people with type 2 diabetes fasting in Ramadan. Documented symptomatic hypos were less likely on a GLP‑1 than on comparison medicines (risk ratio 0.38). Stomach side effects, nausea and vomiting were more likely.4 Three of the four compared against sulfonylureas.4
  • Tirzepatide. A Bangladeshi study followed 109 adults with diabetes on tirzepatide 2.5 mg through Ramadan 2025. About 12% had mild stomach events and none had a hypo. It had no comparison group, and a drug company paid for it.16
  • Weight-only users. A 2023 review found "a dearth of studies" on GLP‑1 users without diabetes during Ramadan.9
RisksThe risks, in brief
  • Stomach effects (feeling sick, vomiting, diarrhoea, constipation) are very common, more than 1 in 10 people, on the UK Mounjaro and Wegovy labels.5,13
  • Dehydration from vomiting or diarrhoea can lead to kidney damage, the UK labels warn.5,13
  • Hypos are more likely with insulin or a sulfonylurea.5
  • Pancreatitis is uncommon (1 in 100 to 1 in 1,000) on both UK labels; the sign is severe stomach pain that won’t go away.5,13,17
  • Gallstones are common (1 in 10 to 1 in 100) on the UK Wegovy label.13
Full detail in Guide 5: Side effects and risks →
Get help now: call 999 for a life-threatening emergency.18 Call if someone with a low is not responding normally or is unconscious, or for severe stomach pain that won’t go away.12,17 For urgent advice that is not an emergency, use NHS 111 in England, Scotland and Wales, online or by phone.19 Northern Ireland has no 111 service: call your GP practice or the GP out-of-hours service.20

Questions people ask

Can I take Mounjaro during Ramadan?

Ramadan guidance does not rule it out. UK pharmacy advice citing IDF-DAR says to finish dose increases 4 to 6 weeks before, and not to start just before Ramadan.1,4 Your prescriber sets the plan.

Does a Mounjaro injection break my fast?

A UK pharmacy article, citing IDF-DAR, says injected GLP‑1s do not invalidate the Islamic fast. It suggests confirming with your religious adviser.1

When should I take Wegovy tablets in Ramadan?

The UK label needs 8 hours without food before the tablet and a 30-minute wait after.2 The UK pharmacy article says this must fit in the overnight eating window, ideally on waking for Suhoor.1

Can I change my injection day for Ramadan?

The UK Mounjaro and Ozempic labels allow it if at least 3 days pass between two doses.5,6 UK pharmacy advice says not to change the day and the dose at the same time.1

When should I break my fast?

IDF-DAR says to break it if blood sugar is below 3.9 mmol/L or above 16.6 mmol/L, or with signs of a hypo, dehydration or illness.3

Shorter answers: Can I take Mounjaro during Ramadan?

How we researched this

On 12 Oct 2026 we read the IDF-DAR 2021 Ramadan guidelines and the South Asian Health Foundation’s UK 2020 update. We also read a July 2026 UK pharmacy article and the UK labels for Mounjaro, Ozempic, Wegovy and Wegovy tablets. Study figures come from the published papers.

We could not open the South East London prescribing committee’s own document, so its advice is quoted as reported in The Pharmacist. We left out insulin and sulfonylurea dose cuts, because they read as dosing instructions. Most Ramadan guidance was written for diabetes, not for weight-loss use.

Before you move on

  • UK pharmacy advice is to finish dose increases at least 4 to 6 weeks before Ramadan.
  • Injections can be fitted round the fast; Wegovy tablets need an 8-hour fast and a 30-minute wait.
  • Hypo risk rises with insulin or a sulfonylurea; know when IDF-DAR says to break the fast.
  • The pharmacy article suggests 1.5 to 2 litres of sugar-free fluid between Iftar and Suhoor; large meals make vomiting more likely.
I have type 2 diabetesSide effects and risksDoctor questions tool

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An independent guide to GLP‑1 medicines. We don't sell medicines, take drug-company money or earn clinic commissions. Once a month: NHS access changes, approvals, safety notices and recalls. How we write

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Sources

  1. Carvalho A. Fasting and weight-loss medications: what to advise your patients. The Pharmacist, 29 July 2026. A UK trade journal for pharmacists; it reports the IDF-DAR and South East London Area Prescribing Committee titration advice. The author, an NHS Lothian dietitian, declares GLP‑1 trial work and advice to the Scottish Medicines Consortium. thepharmacist.co.uk
  2. Novo Nordisk. Wegovy tablets (oral semaglutide): UK SmPC, first authorised 11 June 2026, date of revision 06/2026. Sections 4.2, 4.6. emc
  3. International Diabetes Federation and DAR International Alliance. Diabetes and Ramadan: Practical Guidelines 2021 (IDF-DAR): ch. 2, 7 (§4.1, §4.2, Figure 5), 8, 10 (§3.5), 15. All working-group members declared dualities of interest; prepared with an educational grant. idf.org (PDF)
  4. Kamrul-Hasan ABM, Pappachan JM, Ashraf H et al. Safety and efficacy of glucagon-like peptide-1 receptor agonists in individuals with type 2 diabetes mellitus fasting during Ramadan: a systematic review and meta-analysis. World J Methodol 2025;15(4):105478. No conflicts of interest declared. Full text · PMID 40900863
  5. Eli Lilly. Mounjaro KwikPen (tirzepatide): UK summary of product characteristics (SmPC, the UK label), date of revision 29 August 2026. Sections 4.2, 4.4, 4.5, 4.6, 4.8, 5.2, 6.4. emc
  6. Novo Nordisk. Ozempic (semaglutide) pens: UK SmPC, date of revision 07/2026. Sections 4.1, 4.2, 4.4, 4.6, 4.8, 5.1, 5.2. emc
  7. MHRA (Medicines and Healthcare products Regulatory Agency). GLP‑1 medicines for weight loss and diabetes: what you need to know. First published 5 June 2025, updated 5 February 2026. gov.uk
  8. Hanif W, Patel V, Ali SN et al. The South Asian Health Foundation (UK) guidelines for managing diabetes during Ramadan: 2020 update (summary algorithm). Supported by an unrestricted educational grant from Boehringer Ingelheim. sahf.org.uk (PDF)
  9. Alayed KM. Glucagon-like peptide-1 (GLP‑1) during Ramadan: narrative review of the published literature. J Obes 2023;2023:8626081. DOI · PMC10761230
  10. MHRA. First GLP‑1 tablet for weight loss approved in the UK. Press release, 11 June 2026. gov.uk
  11. Hassanein M, Alawadi F, AlKadhim I et al. O-SEMA-FAST: oral semaglutide use in adults with type 2 diabetes during Ramadan. Diabetes Ther 2025. Funded by Novo Nordisk. DOI · PMID 40016571
  12. NHS. Low blood sugar (hypoglycaemia). Opened 12 October 2026. nhs.uk
  13. Novo Nordisk. Wegovy FlexTouch (semaglutide) pens: UK summary of product characteristics (SmPC), date of revision 09/2026. Sections 4.1, 4.2, 4.4, 4.5, 4.6, 4.8, 5.1, 5.2, 6.3, 6.4. emc
  14. NHS. Dehydration. Opened 12 October 2026. nhs.uk
  15. Mozaffarian D, Agarwal M, Aggarwal M et al. Nutritional priorities to support GLP‑1 therapy for obesity: a joint advisory from four US societies. Am J Clin Nutr 2025;122:344–367. Four authors declared Novo Nordisk ties and five Eli Lilly ties. Full text
  16. Rahman MH, Selim S, Afsana F et al. Safety and effectiveness of tirzepatide during Ramadan fasting: real-world evidence from patients with type 2 diabetes in Bangladesh. Diabetes Obes Metab 2026. Sponsored by Beximco Pharmaceuticals PLC. DOI · PMID 41342185
  17. MHRA. Drug Safety Update: GLP‑1 receptor agonists and dual GLP‑1/GIP receptor agonists: strengthened warnings on acute pancreatitis, including necrotising and fatal cases. Volume 19, issue 6, 29 January 2026. gov.uk
  18. NHS. When to call 999. Page last reviewed 3 February 2023. nhs.uk
  19. NHS. When to use NHS 111 online or call 111. Opened 12 October 2026. nhs.uk
  20. nidirect (Northern Ireland government). GP out of hours service. Opened 12 October 2026. nidirect.gov.uk

Last checked 12 Oct 2026 · Next review due 12 Oct 2027 · Report an error

How this post was made. Written by the GLP Guidebook team from the sources above. It's general information, not medical advice. Talk to a qualified doctor, nurse or pharmacist before a fast, and before starting, stopping or changing any medicine. How we write