Do GLP-1 Medicines Cause Hypoglycemia? (October 2026)

01 · The core answer

Do GLP-1 medicines cause hypoglycemia?

The honest answer is that it depends on the whole of your medicine list, not on the GLP-1 alone. The product information for Mounjaro (tirzepatide) is clear on one point: if you also use insulin or a sulfonylurea, the doses of those medicines may need adjusting because of the risk of low blood sugar.¹¹³

That does not mean the medicines must not be combined. It means the combination needs planning with the clinician who looks after your diabetes.

02 · Decision

Is this relevant to me?

It is most relevant if you have diabetes and use insulin or a sulfonylurea, or if you are about to start a GLP-1 medicine while on either. Mounjaro is licensed in the UK for weight management in adults and for type 2 diabetes, so the two groups of patients can look quite different.¹

If you do not have diabetes and take no glucose-lowering medicines, your concern is usually different: you want to understand symptoms such as feeling shaky, light-headed or tired.

Related guides: Can mounjaro cause hypoglycemia and How does glp1 cause weight loss.

03 · How GLP-1 medicines work

How GLP-1 medicines act on blood sugar and appetite

Tirzepatide activates two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹

A medicine that changes how the body responds to insulin sounds as if it could push glucose too low. Tell your prescriber about every medicine you take, because the risk of low blood sugar depends on what else you use.

In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

04 · Insulin and sulfonylureas

Insulin and sulfonylureas: where the risk sits

Insulin and sulfonylureas are the medicines to raise with your prescriber first. The documented position is that their doses may need adjusting because of the risk of low blood sugar.¹¹³

Insulin and sulfonylureas do not have to be avoided with Mounjaro, but you should not adjust anything yourself. Changing an insulin dose without guidance can cause problems in either direction, so the adjustment is made with your prescriber or diabetes team.

Practical points to raise in a consultation or review:

• Every glucose-lowering medicine you use, including tablets and injections.
• Whether you have ever had a low blood sugar episode and how it felt.
• How you currently monitor your glucose, and whether that routine should change.
• Any change in how much you are eating, because your needs may shift.

Your prescriber can then agree a plan, including when doses should be reviewed as your treatment is stepped up.

05 · Mounjaro specifically

Can Mounjaro cause hypoglycemia?

For Mounjaro the same rule applies: low blood sugar risk is the reason insulin and sulfonylurea doses may need adjusting.¹¹³ Our guide to Mounjaro hypoglycemia symptoms goes through it in more detail.

Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity, and individual results vary.¹

Because Mounjaro is licensed for weight management in adults and for type 2 diabetes, the prescriber's questions will differ depending on why you are taking it. Tell them if you have diabetes, even if you are asking about weight.¹

06 · Without diabetes

Can you be hypoglycemic without being diabetic?

Yes, low blood sugar can occur in people without diabetes, though it has many possible causes and is not something to self-diagnose. A doctor should decide what is behind repeated episodes.

If you have no diabetes and take no glucose-lowering medicine, episodes of shakiness, sweating or confusion that keep happening deserve a medical review rather than a guess. Mention that you take a GLP-1 medicine, because it is part of the picture.

Our weight loss clinic team can discuss any symptoms that appear during treatment as part of ongoing monthly reviews.

07 · Symptoms and lookalikes

Symptoms of low blood sugar and what mimics them

Low blood sugar can cause shakiness, sweating or confusion.

Other things can feel similar, including the stomach-related effects some people get while treatment is stepped up. Our guides on GLP-1 and dizziness and GLP-1 and indigestion help separate those out.

If an episode was severe, or you were confused or unable to help yourself, get medical help straight away.

Tell your prescriber about any new or lasting symptom. You can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹

08 · Reducing the risk

How to avoid hypoglycemia on a GLP-1 medicine

A medicines review before you start matters, especially if you use insulin or a sulfonylurea, because their doses may need adjusting.¹¹³

Beyond that, sensible habits include:

• Being fully honest in your consultation about all medicines and any past low blood sugar episodes.
• Not changing any diabetes medicine on your own initiative.
• Telling your prescriber if your eating pattern changes noticeably, particularly if you are eating much less.
• Keeping scheduled reviews, so dose changes are made deliberately rather than by default.
• Raising symptoms early rather than waiting to see if they pass.

Our aftercare includes ongoing monthly reviews, dose-titration and follow-up assessments by the prescribing team, plus side-effect support. Repeat orders re-check suitability, and there is no auto-shipping.

09 · What helps immediately

What helps hypoglycemia immediately?

If you have diabetes, follow the written hypoglycemia plan your diabetes team has given you; that is the authoritative guide for you. It will say what to take, how to check and when to seek help.

If anyone is drowsy, confused, cannot swallow safely or does not recover, get medical help straight away or call 999.

If you do not have diabetes and feel unwell, sit down, tell someone nearby, and get medical advice. Afterwards, make sure your prescriber or GP knows what happened, what you had eaten and which medicines you take.

Do not take an extra dose of anything, skip or adjust a diabetes medicine, or stop treatment because of one episode without speaking to a clinician first.

10 · Timing and stopping

What happens if you stop

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹ Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average. Stopping should always be planned with your prescriber, with diet and activity habits ready to carry the load.

If you use insulin or a sulfonylurea and you stop a GLP-1 medicine, ask your diabetes team whether doses need to change again. The adjustment that suited you on treatment may not suit you afterwards.

11 · Getting treatment safely

Getting a GLP-1 medicine safely in the UK

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions). Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.⁴⁶

EverydayMeds is a GPhC-registered UK online pharmacy (registration 9012878). Our process is a free online consultation, review by a GPhC-registered prescriber, dispensing and dispatch, then free next-day tracked delivery in temperature-controlled packaging. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

Supply is official LillyDirect supply, so you receive genuine KwikPens.

12 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹ If you are pregnant or planning a pregnancy, Mounjaro must not be used during pregnancy and should be stopped at least one month before trying to conceive.