Can Ozempic, Mounjaro and other GLP‑1 medicines cause low blood sugar?
Why Ozempic and Mounjaro seldom cause a hypo alone, why insulin, glimepiride and gliclazide change that, and why the numbers you see differ.
Written for India. Reading from the US? US versionComing soon
Not often on their own. In the US Ozempic (semaglutide) label’s trial, 1.6% to 3.8% on Ozempic alone had a low with symptoms (70 mg/dL or below), vs 0% on a dummy injection. Ozempic and Mounjaro (tirzepatide) push out insulin mainly when blood sugar is high. Lows are far more common with insulin or a sulfonylurea such as glimepiride.
Key takeaways
- Ozempic and Mounjaro seldom cause low blood sugar alone, because their labels say they release insulin in a glucose-dependent way: mainly when sugar is high, less as it falls.1,2
- In the Ozempic label's 30-week trial of Ozempic alone, 1.6% to 3.8% had a low with symptoms at or below 70 mg/dL, against 0% on a dummy injection.1
- With basal insulin, 29.8% on Ozempic 1 mg had a low at or below 70 mg/dL, vs 15.2% on a dummy injection; with a sulfonylurea, 17.3% to 24.4%.1
- The Ozempic and Mounjaro labels tell doctors to consider lowering a sulfonylurea or insulin dose when the GLP‑1 medicine is started.1,2
- India's RSSDI-ESI 2020 guideline describes treating a low in an alert person with 15 to 20 g of sugar or glucose, about four teaspoons.9
- GLP‑1 medicines are prescription-only in India. A government statement on 1 Apr 2026 said only endocrinologists, internal-medicine specialists and cardiologists can prescribe them.11 CDSCO expert-committee minutes attach a similar condition to some approvals (endocrinologist or internal-medicine specialist), but we found no rule covering every brand.12
- This post describes what labels and guidelines say. It is not a plan for changing your own doses.
- Low blood sugar is one risk among several. See Guide 5, Side effects and risks.
On this page
- Can a GLP‑1 medicine cause a low on its own?
- Why do insulin and sulfonylureas change the risk?
- How often did lows happen in the trials?
- What do the labels say about lowering other doses?
- What does low blood sugar feel like?
- How do guidelines describe treating a low?
- Can you get a low without diabetes?
- What about fasting for Ramadan or Navratri?
- Questions people ask
- How we researched this
- Sources
Can a GLP-1 medicine cause a low on its own?
Not often. Semaglutide and tirzepatide make the pancreas release insulin mainly when blood sugar is high, and less as it falls. On their own, they seldom push it too low.1,2
Insulin is the hormone that moves sugar out of the blood. Glucagon is its opposite: it tells the liver to release sugar. The Ozempic label says semaglutide raises insulin and lowers glucagon "in a glucose-dependent manner".1 The label goes on: "when blood glucose is high, insulin secretion is stimulated". In plain words, the push works mainly when blood sugar is high and fades as it falls.1 It does not switch off completely: the Wegovy label says semaglutide "lowers blood glucose and can cause hypoglycemia".3
The Mounjaro label says the same of tirzepatide.2 The Ozempic label adds one more check. When researchers made blood sugar drop on purpose, semaglutide did not block the body's glucagon rescue.1 Our guide on what GLP‑1 medicines do explains the rest of the mechanism, and What is a GLP‑1? explains the hormone behind the name.
Why do insulin and sulfonylureas change the risk?
Insulin and sulfonylurea tablets can each cause a low by themselves. Adding a GLP‑1 medicine puts a second sugar-lowering effect on top, and the labels warn of more lows.1,9,10
Sulfonylureas are older diabetes tablets. They work by making the pancreas release insulin.10 India's RSSDI-ESI guideline lists gliclazide, glimepiride, glipizide and glibenclamide, with low sugar and weight gain as their main problems.9 The same guideline says gliclazide MR and glimepiride have a lower risk of lows, and are preferred in South Asian patients.9
The US glimepiride label says all sulfonylureas, including glimepiride, can cause severe lows.10 It says lows are more likely when you eat too little, after long or hard exercise, or after alcohol.10 Semaglutide, for its part, cuts calorie intake, probably by acting on appetite.3 The Ozempic label warns that the combination can cause lows, including severe ones.1
The American Diabetes Association (ADA) lists insulin, sulfonylureas and meglitinides as risks for severe lows.8 Metformin is not on that list.8
How often did lows happen in the trials?
On Ozempic or Mounjaro, alone or with metformin, at most about 4 in 100 people had a low. In the trials of either medicine alone, none had a severe one. With insulin or a sulfonylurea, about 6% to 30% had at least one low, depending on the trial, dose and measure.1,2,4,5
Rybelsus tablets were slightly different. In their 26-week trial of the tablets alone, 1% on the 7 mg dose had a severe low, vs 0% on dummy tablets.4
The labels count lows in more than one way, and the choice changes the number a lot. The Ozempic label reports three counts for the same trials:1
- The wider count: a low with symptoms and a reading at or below 70 mg/dL. This picks up milder lows. The ADA treats anything under 70 mg/dL as a low.1,6
- The stricter count: a low with symptoms and a reading at or below 56 mg/dL, or a severe low. The Mounjaro label uses a similar line, below 54 mg/dL, and gives only this count.1,2
- Severe: the person needed someone else's help, whatever the reading.1
So one Ozempic trial can read as 3.8% or 0%, depending on the count.1 If you see 2% to 4% quoted for Ozempic alone, that matches the wider count, rounded. On the stricter count, 1.6% of people on the dummy injection had a low, and nobody on Ozempic did. That is about 2 people out of 129, a very small difference.1
| Taken with | Medicine | Low sugar on it | On a dummy |
|---|---|---|---|
| Nothing else | Ozempic 0.5 or 1 mg, 30 weeks | Wider count (70 or below): 1.6–3.8%. Stricter count (56 or below, or severe): 0%. Severe: 0%1 | 0%; 1.6%; 0%1 |
| Nothing else | Mounjaro 5–15 mg, 40 weeks | Below 54: 0%. Severe: 0%. No wider count in the label2 | 1%; 0%2 |
| Metformin | Ozempic 1 mg or Mounjaro 5–15 mg, 40 weeks | Below 54: 0.4% on Ozempic, 0.2–1.7% on Mounjaro5 | No dummy group5 |
| Basal insulin | Ozempic 0.5 or 1 mg, 30 weeks | Wider count: 16.7–29.8%. Stricter count: 8.3–10.7%. Severe: 0–1.5%1 | 15.2%; 5.3%; 0%1 |
| Basal insulin | Mounjaro 5–15 mg, 40 weeks | Below 54: 14–19%. Severe: up to 2%2 | 13%; 0%2 |
| Insulin, cut by 20% at the start | Rybelsus tablets 7 or 14 mg, 52 weeks | Below 54: 26–30%4 | 32% (dummy tablets)4 |
| A sulfonylurea | Ozempic 0.5 or 1 mg | Wider count: 17.3–24.4%. Stricter count: 6.5–10.4%. Severe: 0.8–1.2%1 | Not given in the label1 |
| A sulfonylurea | Mounjaro 5–15 mg, up to 104 weeks | Below 54: 9.9–13.8%. Severe: up to 0.6%2 | Not given in the label2 |
| Diet alone or 1–3 diabetes tablets, which could include a sulfonylurea | Wegovy 2.4 mg (STEP 2) | Below 54: 6.2%3 | 2.5%3 |
Share of people with at least one low during each trial; readings in mg/dL. Where three figures sit in the dummy column, they follow the order of the counts. From the US labels for Ozempic (May 2026), Mounjaro (Aug 2026), Rybelsus (Jan 2026) and Wegovy (Jun 2026). Metformin row: SURPASS-2 (NEJM 2021, funded by Eli Lilly). Trials differ in length, people and definitions, so compare within a row, not across rows.
Look at the insulin rows. Lows were frequent even on the dummy: 13% in the Mounjaro trial, and 15.2% on the wider count in the Ozempic trial.1,2 Much of the risk comes from the insulin itself, and the GLP‑1 medicine adds to it.1,2 In the Wegovy label, the risk was higher again when Wegovy was used with a sulfonylurea.3
- Lower blood sugar is the point of these medicines in diabetes. HbA1c is your average sugar over 2 to 3 months.6 In SURPASS-2 it fell by 1.86 points on Ozempic 1 mg and 2.01 to 2.30 on Mounjaro.5 The harms below come with that.
- Stomach effects are the most common. In SURPASS-2, 17% to 22% felt sick (nausea) on tirzepatide, and 18% on semaglutide.5
- Pancreatitis. The warning sign is severe stomach pain that won't go away, sometimes spreading to the back.1
- Dehydration can hurt the kidneys. Vomiting or diarrhoea can dry you out, and kidney injury has been reported.1
- Gallstones. In the Ozempic trials, 1.5% (0.5 mg) and 0.4% (1 mg) had gallstones, vs none on a dummy injection. The Mounjaro label reports gallbladder problems in 0.6% vs 0%.1,2
- Pregnancy. The Ozempic label says to stop at least 2 months before a planned pregnancy, because semaglutide stays in the body a long time. The Mounjaro label says it may harm an unborn baby, based on animal studies, and can make the contraceptive pill less reliable for 4 weeks after starting and after each dose rise.1,2
- Thyroid warning. Ruled out by the US label for anyone with a personal or family history of medullary thyroid cancer (MTC), or with MEN 2 (multiple endocrine neoplasia type 2); tell your doctor if this applies.1
What do the labels say about lowering other doses?
The Ozempic, Mounjaro and Wegovy labels tell doctors to consider a lower sulfonylurea or insulin dose when starting.1,2,3
The Ozempic label says a lower sulfonylurea or insulin dose "may" reduce the risk of a low.1 It asks doctors to warn patients about the risk and teach them the signs.1 The Wegovy label adds that people with diabetes should have their blood sugar checked before starting and during treatment.3
The labels we read give no fixed amount. In one Rybelsus trial, everyone on insulin cut it by 20% at the start.4 That was a trial rule. In that trial, lows below 54 mg/dL hit 26% to 30% on the tablets, vs 32% on dummy tablets.4 Our answer on Rybelsus 3 mg covers the tablet's starting dose.
India's RSSDI-ESI guideline asks for close watch on lows in anyone taking insulin, sulfonylureas or meglitinides.9 It also urges caution with sulfonylureas in older people and in people with kidney disease.9
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What does low blood sugar feel like?
Shaking, sweating, hunger, a fast heartbeat, dizziness and confusion are common signs. The ADA counts a reading below 70 mg/dL as a low.1,6
The Ozempic Medication Guide lists these signs:1
- dizziness or light-headedness, shakiness, feeling jittery or weak
- sweating, hunger, headache, a fast heartbeat
- blurred vision or slurred speech
- anxiety, irritability, mood changes, confusion or drowsiness
The ADA's 2026 Standards of Care sort lows into three levels:6
Some people feel nothing when their sugar is low. The ADA calls this hypoglycaemia unawareness.7 The glimepiride label says warning signs can be weaker in older people. The same goes for people on beta-blockers, a blood pressure medicine.10
How do guidelines describe treating a low?
The ADA calls it the "15-15 rule": 15 g of fast sugar, then a recheck after 15 minutes. If sugar is still below 70 mg/dL, the step is repeated.7
India's RSSDI-ESI guideline describes the same steps. It gives 15 to 20 g of carbohydrate, "four teaspoons of sugar or glucose", by mouth to a conscious person.9 Sugar is checked again after 15 minutes, and the dose repeated if it is still low.9 A meal or snack follows once sugar is back to normal, so it doesn't drop again.9
- CheckOn the ADA page, a reading of 70 mg/dL or below counts as a low.7
- 15 gThe ADA prefers glucose, and also lists 1 tablespoon of sugar or half a cup of juice. RSSDI-ESI gives 15–20 g, about four teaspoons of sugar or glucose.6,7,9
- 15 minThe ADA says to recheck; if sugar is still below 70 mg/dL, another 15 g.7
- AfterThe ADA page and RSSDI-ESI both describe a snack or meal, so sugar stays up.7,9
The ADA says to avoid foods high in fat or protein for the first treatment, such as chocolate.6,7 Fat may slow the rise in sugar.6 It also warns that sulfonylureas may bring the low back unless more food follows.6
Sugar by mouth is only for someone who is alert.6 For someone who can't take sugar by mouth, the ADA describes glucagon, a rescue injection or nasal spray.6,8 India's RSSDI-ESI guideline also describes glucose into a vein. It adds that glucagon should be avoided when a sulfonylurea caused the low.9 The ADA says glucagon should be prescribed for everyone on insulin or at high risk of lows.6
Can you get a low without diabetes?
It has been reported, but the Wegovy weight trials did not count lows systematically, so the label gives no rate.3
In a heart trial without diabetes, the Wegovy label reports 3 serious lows on Wegovy and 1 on a dummy injection.3 In that trial, people who had had weight-loss surgery had more serious lows: 2 of 87 on Wegovy (2.3%) vs 0 of 97 on the dummy.3 The label calls past bariatric surgery a risk factor for lows.3
Our answer to "Can you take Ozempic without diabetes?" covers which brands are approved for weight in India.
What about fasting for Ramadan or Navratri?
Low sugar is a main danger of fasting with diabetes. India's RSSDI-ESI guideline changes sulfonylurea and insulin doses for Ramadan, but not the GLP‑1 dose.9
The guideline names low sugar and dehydration as the main fasting dangers.9 Its Ramadan table moves or halves sulfonylurea doses around suhur and iftar.9 For GLP‑1 medicines, it says the dose steps should be done 6 weeks before Ramadan, with no change during it.9
For Hindu fasts such as Navratri, the guideline says there are no universal rules, and data are scarce.9 Our fasting post covers this in more depth: Fasting for Navratri, Ramadan or Karva Chauth on a GLP‑1 medicine
Questions people ask
Can Ozempic alone cause a hypo?
Not often, and nobody had a severe one. In the label's 30-week trial, 1.6% to 3.8% on Ozempic had a low with symptoms at or below 70 mg/dL, vs 0% on a dummy injection. On a stricter count, at or below 56 mg/dL, it was 0% vs 1.6%.1
Is glimepiride a GLP-1 medicine?
No. Glimepiride is a sulfonylurea, a tablet that lowers sugar by making the pancreas release insulin. A tablet sold in India as "GLP 1mg" contains glimepiride, so the name can mislead.10,13
Does taking metformin with a GLP-1 medicine cause lows?
Not often in the SURPASS-2 trial, where everyone took metformin. Lows below 54 mg/dL happened in 0.4% on Ozempic 1 mg and 0.2% to 1.7% on Mounjaro.5
Do I need to stop my sulfonylurea when I start a GLP-1 medicine?
The labels don't say stop. They tell doctors to consider lowering the sulfonylurea or insulin dose when a GLP-1 medicine is started. Whether and by how much is your doctor's decision.1,2
What blood sugar counts as low?
The ADA counts below 70 mg/dL as a low, and below 54 mg/dL as a more serious one. A severe low is one where you need someone else's help, at any reading.6
Can you get a low on Wegovy for weight loss only?
It has been reported. The Wegovy label says lows were not counted systematically in its weight trials. In a heart trial without diabetes, there were 3 serious lows on Wegovy vs 1 on a dummy injection.3
How we researched this
On 5 October 2026 we read the US labels for Ozempic, Wegovy, Rybelsus, Mounjaro and glimepiride. We took every rate of low blood sugar from the labels' own tables. Where a label gives more than one count, we show each, because the counts differ several-fold. The metformin figures come from the SURPASS-2 paper. We read the ADA's 2026 Standards of Care, two ADA patient pages, and India's RSSDI-ESI 2020 guideline.
We could not find India's prescribing information for these brands online, so the figures are from US labels. We found Indian studies of how often sulfonylureas are prescribed, but each covered one hospital. So we used the RSSDI-ESI guideline's wording instead. We describe how a low is treated as the guidelines describe it. We don't give dose changes, because only a doctor can set those.
Before you move on
- On their own, Ozempic and Mounjaro caused few lows in their trials, and no severe ones.
- Insulin and sulfonylureas such as glimepiride and gliclazide raise the risk.
- The labels tell doctors to consider lowering those doses at the start.
- Someone confused, fitting or unconscious with low sugar needs 112.
More from the India blog
Mounjaro side effects: what the trials and the label say
What is a GLP‑1? The hormone, the medicines and the jargon
Fasting for Navratri, Ramadan or Karva Chauth on a GLP‑1 medicine
The monthly India update
An independent guide to GLP‑1 medicines. We don't sell medicines, take drug-company money or earn clinic commissions. Once a month: new brands, price changes, approvals and recalls. How we write
Sources
- Novo Nordisk. Ozempic (semaglutide) injection, US prescribing information and Medication Guide, revised May 2026. Sections 4, 5.2, 5.5, 5.6, 5.9, 6.1 (Table 2), 7.1, 8.1, 8.3, 12.1, 12.2 (US label, not the Indian one). PDF
- Eli Lilly. Mounjaro (tirzepatide) injection, US prescribing information, revised August 2026. Sections 5.3, 5.8, 6.1 (Table 2), 7.1, 7.2, 8.1, 8.3, 12.1, 12.2 (US label, not the Indian one). PDF
- Novo Nordisk. Wegovy (semaglutide) injection and tablets, US prescribing information, revised June 2026. Sections 5.4, 6.1, 12.2, 14 (US label, not the Indian one). PDF
- Novo Nordisk. Rybelsus and Ozempic (semaglutide) tablets, US prescribing information, revised January 2026. Section 6.1, Table 3, and section 14 (US label, not the Indian one). PDF
- Frías JP, et al. Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes (SURPASS-2). N Engl J Med. 2021;385:503–15. 1,879 people, all on metformin, 40 weeks. Funded by Eli Lilly. DOI · PMID 34170647
- American Diabetes Association. 6. Glycemic goals, hypoglycemia, and hyperglycemic crises: Standards of Care in Diabetes 2026. Diabetes Care. 2026;49(Suppl 1). Table 6.4, recommendations 6.15–6.16. Declared interests: 2 of the 20 Professional Practice Committee members who write the Standards declare ties to Novo Nordisk and 1 to Eli Lilly (source 16). DOI · Full text
- American Diabetes Association. Signs, symptoms, and treatment for hypoglycemia (low blood glucose). Patient page, checked 5 October 2026. Link
- American Diabetes Association. Severe hypoglycemia (severe low blood glucose). Patient page, checked 5 October 2026. Link
- Chawla R, Madhu SV, Makkar BM, et al. RSSDI-ESI clinical practice recommendations for the management of type 2 diabetes mellitus 2020. Indian J Endocrinol Metab. 2020;24(1):1–122. Joint guideline of RSSDI and the Endocrine Society of India. Hypoglycaemia, drug table and fasting sections. DOI · Full text
- Glimepiride tablets, US prescribing information (DailyMed), revised September 2026. Sections 5.1 and 12.1 (US label). Link
- Press Information Bureau (PIB Research). GLP-1 Drugs: Use, Risks, and Regulation. Government backgrounder, 1 April 2026. PDF
- CDSCO. Recommendations of the Subject Expert Committee (Endocrinology & Metabolism): 20–21 April 2023, item 1 (tirzepatide), and 13–14 February 2024, items 3–4 (semaglutide, Novo Nordisk). Committee minutes. April 2023 PDF · archived copy · February 2024 PDF · archived copy
- PharmEasy, Tata 1mg and Netmeds product listings for "GLP 1mg Tablet", composition line (glimepiride 1 mg). Pharmacy listings, checked 5 October 2026 (not linked).
- Business Standard. Novo Nordisk launches Ozempic in India at ₹2,200/week amid patent battles. 12 December 2025. Link
- Business Standard. Eli Lilly launches Mounjaro in India. 20 March 2025. Link
- American Diabetes Association Professional Practice Committee. Disclosures: Standards of Care in Diabetes 2026. Diabetes Care. 2026;49(Suppl 1):S358–S362. Committee members' declared ties, checked 5 October 2026. Full text
Last checked 5 Oct 2026 · Next review due 5 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 before starting, stopping or changing any medicine. How we write