GLP-1 low blood sugar (hypoglycemia) warning: what the labels say

Short answer: every US label for Ozempic, Wegovy, Rybelsus, Mounjaro, Zepbound, Saxenda, Victoza and Trulicity has a hypoglycemia warning. On a GLP-1 alone, trial rates of low blood sugar were close to placebo. The risk climbs, including severe episodes, when the drug is combined with insulin or a sulfonylurea. The Wegovy and Zepbound labels also say hypoglycemia has been seen in adults without type 2 diabetes. Below are the label wording, the trial numbers and what the Canadian monographs add.

On this page: US warning · Without insulin · With insulin · With a sulfonylurea · Without diabetes · Canada and driving · What to log

The US warning, label by label

All eight US labels on DailyMed (checked November 5, 2026) say a lower dose of the sulfonylurea (or other insulin secretagogue) or insulin may reduce the risk; seven say it "may be lowered by a reduction in the dose" (Rybelsus says "dosage"), and Wegovy tells prescribers to "consider reducing the dose" when starting. They also tell prescribers to inform patients of the risk and educate them on its signs and symptoms. The titles differ: the diabetes products frame it around combination use, while Wegovy, Zepbound, Saxenda and Victoza use a plain "Hypoglycemia" heading.

Medication	Section	Warning title	What it adds
Ozempic (semaglutide injection)	5.5	Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin	Risk higher with a sulfonylurea or insulin, including severe hypoglycemia
Wegovy (semaglutide injection and tablets)	5.4	Hypoglycemia	Lowers blood glucose and can cause hypoglycemia; not evaluated in type 1 diabetes or with insulin; monitor glucose in diabetes
Rybelsus and Ozempic tablets (oral semaglutide)	5.4	Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin	Risk higher with a sulfonylurea or insulin, including severe hypoglycemia
Mounjaro (tirzepatide)	5.3	Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin	Risk higher with a sulfonylurea or insulin, including severe hypoglycemia
Zepbound (tirzepatide)	5.7	Hypoglycemia	Lowers blood glucose and can cause hypoglycemia; also seen in adults without type 2 diabetes; monitor glucose in diabetes
Saxenda (liraglutide 3 mg)	5.4	Hypoglycemia	Higher risk in type 2 diabetes on a sulfonylurea or insulin; monitor glucose in type 2 diabetes; pediatric risk noted
Victoza (liraglutide)	5.4	Hypoglycemia	Higher risk with a sulfonylurea or insulin; in children 10 and older, higher regardless of insulin or metformin
Trulicity (dulaglutide)	5.3	Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin	Risk higher with a sulfonylurea or insulin, including severe hypoglycemia

Blood glucose thresholds in the labels are in mg/dL. For Canadian readers: 70 mg/dL is about 3.9 mmol/L, 56 mg/dL about 3.1 mmol/L and 54 mg/dL about 3.0 mmol/L. "Severe" hypoglycemia means an episode that needed another person's help.

Low blood sugar on a GLP-1 without insulin or a sulfonylurea

These are the placebo-controlled trials in each US label where people were not on insulin or a secretagogue. The drug alone rarely pushed glucose below the thresholds.

Medication	Trial	On the drug	Placebo
Ozempic	Monotherapy, 30 weeks	Symptomatic, 70 mg/dL or less: 1.6% (0.5 mg), 3.8% (1 mg); severe: 0%	0% symptomatic; severe 0%
Rybelsus / Ozempic tablets	Monotherapy, 26 weeks	Under 54 mg/dL: 0% (7 mg), 0% (14 mg); severe: 1% (7 mg), 0% (14 mg)	Under 54: 1%; severe 0%
Mounjaro	Monotherapy, 40 weeks	Under 54 mg/dL: 0% (5, 10 and 15 mg); severe: 0%	Under 54: 1%; severe 0%
Trulicity	Add-on to metformin, 26 weeks	Under 54 mg/dL: 0.3% (0.75 mg), 0.7% (1.5 mg); severe: 0%	Under 54: 0%; severe 0%
Victoza	Add-on to metformin, 26 weeks	Able to self-treat: 3.6%; not able to self-treat: 0.1%	Self-treat 2.5%; not able 0%

Only two rows show severe events without insulin or a sulfonylurea: Rybelsus 7 mg (1% of 175 people in the 26-week monotherapy trial) and Victoza with metformin (0.1% not able to self-treat). Compare each drug with its own placebo group; the trials used different definitions and lengths.

With insulin

Adding a GLP-1 to insulin is where the trial rates get large, and some of that comes from the insulin itself, which is why the placebo groups are high too.

Medication	Trial	On the drug	Placebo
Ozempic	Add-on to basal insulin ± metformin, 30 weeks	Symptomatic 70 mg/dL or less: 16.7% (0.5 mg), 29.8% (1 mg); 56 mg/dL or less or severe: 8.3%, 10.7%; severe: 0%, 1.5%	15.2%; 5.3%; 0%
Rybelsus / Ozempic tablets	Add-on to insulin ± metformin, 52 weeks	Under 54 mg/dL: 26% (7 mg), 30% (14 mg); severe: 0%, 1%	32%; severe 1%
Mounjaro	Add-on to basal insulin ± metformin, 40 weeks	Under 54 mg/dL: 16% (5 mg), 19% (10 mg), 14% (15 mg); severe: 0%, 2%, 1%	13%; severe 0%
Trulicity	With insulin glargine ± metformin, 28 weeks	Under 54 mg/dL: 14.7% (1.5 mg); severe: 0.7%	9.3%; severe 0%
Trulicity	With prandial insulin, 52 weeks (no placebo)	Under 54 mg/dL: 77% (0.75 mg), 69% (1.5 mg); severe: 2.7%, 3.4%	n/a
Saxenda	Type 2 diabetes on basal insulin, weight trial	Severe: 3 of 195 (1.5%); no meaningful difference under 54 mg/dL	Severe: 2 of 197 (1%)

The Wegovy label says use with insulin has not been evaluated. In Canada, the Saxenda monograph says Saxenda and insulin should not be used together.

With a sulfonylurea

Every label singles out sulfonylureas (such as glimepiride, gliclazide or glyburide). The labels report these rates when the GLP-1 was combined with one.

Medication	Trial	Hypoglycemia reported (US label)
Ozempic	With a sulfonylurea	Severe 0.8% (0.5 mg) and 1.2% (1 mg); symptomatic 17.3% and 24.4%; 56 mg/dL or less or severe 6.5% and 10.4%
Mounjaro	With a sulfonylurea, up to 104 weeks	Under 54 mg/dL 13.8% (5 mg), 9.9% (10 mg), 12.8% (15 mg); severe 0.5%, 0%, 0.6%
Zepbound	Study 2 (type 2 diabetes, BMI 27+)	Under 54 mg/dL 10.3% with a sulfonylurea vs 2.1% without; 4.2% overall vs 1.3% on placebo
Saxenda	Type 2 diabetes weight trial	Under 54 mg/dL 28.2% (31 of 110) with a sulfonylurea vs 12.7% on placebo; 7.1% without one vs 4.5%; all 3 severe cases (0.7%) were on a sulfonylurea
Victoza	Add-on to metformin + glimepiride, 26 weeks	Not able to self-treat 2.2% vs 0% on placebo; able to self-treat 27.4% vs 16.7%
Victoza	Add-on to glimepiride, 26 weeks	Not able to self-treat 0.1% vs 0%; able to self-treat 7.5% vs 2.6%
Trulicity	With a sulfonylurea, 78 weeks	Under 54 mg/dL 20% (0.75 mg) and 21% (1.5 mg); severe 0% and 0.7%
Trulicity	Add-on to glimepiride, 24 weeks	Under 54 mg/dL 3.3% (1.5 mg) vs 0% on placebo; severe 0%

The Victoza label adds that across five adult glycemic control trials of at least 26 weeks, severe hypoglycemia occurred in 8 Victoza-treated patients (7.5 events per 1,000 patient-years), and 7 of the 8 were taking a sulfonylurea.

Without diabetes: Wegovy, Zepbound and Saxenda

Wegovy: in adults with type 2 diabetes and a BMI of 27 or more (Study 3), glucose under 54 mg/dL occurred in 6.2% on Wegovy vs 2.5% on placebo, at 10.7 episodes per 100 patient-years vs 7.2 on semaglutide 1 mg and 3.2 on placebo. In adults without diabetes, hypoglycemia was not systematically captured; the cardiovascular outcomes trial recorded 3 serious episodes on Wegovy vs 1 on placebo. People with a history of bariatric surgery, which the label calls a risk factor, had more serious hypoglycemia on Wegovy (2 of 87, 2.3%) than placebo (0 of 97).
Zepbound: in Study 2 (type 2 diabetes), 4.2% vs 1.3% on placebo. In Study 1 (no diabetes), there was no systematic capture, but plasma glucose under 54 mg/dL was reported in 0.3% on Zepbound and in no one on placebo.
Saxenda: in adults without diabetes there were no glucose meters or diaries; spontaneously reported, unconfirmed symptomatic episodes came from 46 of 2,962 people on Saxenda (1.6%) vs 19 of 1,729 on placebo (1.1%).

The Wegovy and Zepbound labels both state that hypoglycemia has been associated with GLP-1 receptor agonists in adults without type 2 diabetes.

Canada: monograph wording and driving

The Canadian product monographs (section 7, Warnings and Precautions, under Endocrine and Metabolism and Driving and Operating Machinery) carry the same core warning. Their extra detail is about driving, which the US labels do not address in the warning.

Monograph	Hypoglycemia and driving (summary)
Ozempic	Higher risk with a sulfonylurea or insulin; no or negligible influence on driving, but take precautions against hypoglycemia while driving when combined; avoid driving if dizzy during escalation
Wegovy	Lowers blood glucose and can cause hypoglycemia; higher risk in type 2 diabetes with insulin or a secretagogue; monitor glucose in type 2 diabetes; same driving advice as Ozempic
Rybelsus	"In rare cases" may cause hypoglycemia that affects driving; precautions while driving with a sulfonylurea or insulin; avoid driving if dizzy during escalation
Mounjaro	Higher risk with a sulfonylurea or insulin; driving precautions when combined; not to be used with other incretin drugs (GLP-1 RAs or DPP-4 inhibitors)
Zepbound	Higher risk in type 2 diabetes with a sulfonylurea or insulin; monitor glucose; patient information says to avoid driving with signs of low blood sugar
Saxenda	Severe hypoglycemia seen in type 2 diabetes trials; "Saxenda and insulin should not be used together"; pediatric glucose under 3 mmol/L 1.6% vs 0.8%
Victoza	Higher risk with a sulfonylurea or insulin; precautions while driving and using machines; higher pediatric risk with metformin with or without basal insulin
Trulicity	Higher risk with a secretagogue or insulin; no driving studies, but precautions while driving with a sulfonylurea or insulin

The Canadian monographs for Ozempic, Rybelsus, Mounjaro, Trulicity and Victoza also say the drug should not be used in type 1 diabetes. Canadian monographs give glucose in mmol/L; the Saxenda pediatric threshold is under 3 mmol/L.

Severe hypoglycemia is also one of the overdose effects listed on the Wegovy, Saxenda and Victoza labels. If too much was taken, see GLP-1 overdose: what the labels say for poison control numbers in the US and Canada.

What to log and tell your prescriber

Every glucose-lowering medicine you take, especially insulin or a sulfonylurea, before you start the GLP-1.
Low readings: the date, time, the number (mg/dL or mmol/L), what you were doing and whether you needed help. The labels separate episodes you treated yourself from severe ones that needed another person.
Symptoms such as shakiness, sweating, dizziness or confusion, and whether they happened while driving.
Dose changes of any of your medicines, since the labels tie the risk to combinations and Canadian monographs tie dizziness to dose escalation.
Any history of bariatric surgery, which the US Wegovy label calls a hypoglycemia risk factor.

For the other class warnings, see GLP-1 drug interactions, GLP-1 kidney and dehydration warning, GLP-1 pancreatitis and gallbladder warnings, GLP-1 diabetic retinopathy warning aspiration under anesthesia, and heart rate and hypersensitivity.

Sources

This page summarizes official product labels as general information. It is not medical advice. Do not start, stop or change any medication, including insulin or a sulfonylurea, without talking to your prescriber. Labels are updated; check the current version for your product.

Frequently asked questions

Can Ozempic, Wegovy, Mounjaro or Zepbound cause low blood sugar?

Yes, and all eight US labels covered here (Ozempic, Wegovy, Rybelsus, Mounjaro, Zepbound, Saxenda, Victoza and Trulicity) carry a hypoglycemia warning in section 5. The diabetes labels (Ozempic, Rybelsus, Mounjaro, Trulicity) title it "Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin": the risk rises, including severe hypoglycemia, when the drug is combined with a sulfonylurea or insulin. The weight-management labels for Wegovy and Zepbound go further and say the drug "lowers blood glucose and can cause hypoglycemia."

How common was low blood sugar in the trials?

It depends heavily on what else people were taking. On a GLP-1 alone, rates were low: in monotherapy trials, blood glucose under 54 mg/dL (3.0 mmol/L) occurred in 0% of people on Mounjaro 5, 10 or 15 mg vs 1% on placebo, and 0% on Rybelsus 7 or 14 mg vs 1% on placebo. With insulin it was much higher: 30% on Rybelsus 14 mg vs 32% on placebo, 14% to 19% on Mounjaro vs 13% on placebo, and 14.7% on Trulicity 1.5 mg vs 9.3% on placebo. Each figure is from that drug's US label.

Does a sulfonylurea make hypoglycemia more likely on a GLP-1?

Yes, according to every label. On Zepbound, hypoglycemia under 54 mg/dL was 10.3% in people also taking a sulfonylurea vs 2.1% in those who were not. On Saxenda it was 28.2% with a sulfonylurea (vs 12.7% on placebo) and 7.1% without one (vs 4.5%). Of the 8 Victoza patients who had severe hypoglycemia in five glycemic control trials, 7 were taking a sulfonylurea. On Trulicity with a sulfonylurea in a 78-week trial, it was 20% (0.75 mg) and 21% (1.5 mg).

Can you get hypoglycemia on Wegovy or Zepbound without diabetes?

It is uncommon but the labels say it has happened. The Wegovy and Zepbound labels say hypoglycemia has been associated with GLP-1 receptor agonists in adults without type 2 diabetes. Hypoglycemia was not systematically captured in those trials. In Zepbound Study 1 (no diabetes), plasma glucose under 54 mg/dL was reported in 0.3% vs no one on placebo. In the Wegovy cardiovascular outcomes trial in people without diabetes, there were 3 serious hypoglycemia episodes on Wegovy vs 1 on placebo. On Saxenda, unconfirmed symptomatic episodes were spontaneously reported by 1.6% vs 1.1% on placebo.

Does bariatric surgery raise the risk?

The US Wegovy label calls a history of bariatric surgery a risk factor for hypoglycemia. In its cardiovascular outcomes trial in adults without type 2 diabetes, people with prior bariatric surgery had more serious hypoglycemia on Wegovy (2.3%, 2 of 87) than on placebo (0%, 0 of 97).

What counts as severe hypoglycemia in these labels?

The labels define severe hypoglycemia as an episode requiring the assistance of another person (Trulicity and Mounjaro add: to actively administer carbohydrate, glucagon or other resuscitative actions). "Clinically significant" or level 2 hypoglycemia is a blood glucose below 54 mg/dL, which is about 3.0 mmol/L, the unit Canadian monographs use.

Should my insulin or sulfonylurea dose be lowered when I start a GLP-1?

That is your prescriber's decision, and Glidedose does not suggest doses. The labels say the risk of hypoglycemia may be lowered by reducing the dose of the sulfonylurea or insulin, and the Wegovy, Zepbound and Saxenda labels tell prescribers to monitor blood glucose before and during treatment in people with diabetes. Never change these doses yourself.

Can Saxenda be used with insulin?

The two countries differ. The US Saxenda label warns that adults with type 2 diabetes on an insulin secretagogue or insulin may have a higher hypoglycemia risk, and reports a trial with basal insulin (severe hypoglycemia in 1.5% vs 1% on placebo). The Canadian Saxenda monograph says "Saxenda and insulin should not be used together" and that it has not been studied in patients taking insulin.

Can I drive on a GLP-1?

The Canadian monographs address this directly. Ozempic, Wegovy, Rybelsus, Mounjaro, Zepbound, Victoza and Trulicity monographs say people taking the drug with a sulfonylurea or insulin should take precautions to avoid hypoglycemia while driving and using machines. Ozempic, Wegovy and Rybelsus add that dizziness can occur during dose escalation and that driving should be avoided if it does. The Saxenda monograph reviewed has no driving statement.

Are children at higher risk?

For Victoza, yes: the US label says the risk of hypoglycemia was higher in patients 10 years and older regardless of insulin or metformin use. In its pediatric trial, 21.2% of Victoza-treated patients with type 2 diabetes had glucose under 54 mg/dL, with no severe episodes. In the Saxenda pediatric trial (no diabetes, but glucose meters were provided), clinically significant hypoglycemia occurred in 1.6% vs 0.8% on placebo.

GLP-1 age limits: children, teens and adults 65+
Which GLP-1s are approved from age 10 or 12 in the US and Canada, teen side-effect differences, and older-adult trial data.GLP-1 drug interactions
Birth control pills, insulin, levothyroxine and oral meds: what the labels say.GLP-1 kidney and dehydration warning
Acute kidney injury wording and trial rates from each label, severe GI rates, and Canada's ESRD rules.GLP-1 pancreatitis and gallbladder warnings
Label rates for pancreatitis, gallstones and enzyme rises, and Canada's do-not-restart rule.Tracking GLP-1 side effects
A practical way to log symptoms so your appointments are more useful.GLP-1 dose schedule
Week-by-week escalation for Ozempic, Wegovy, Mounjaro and Zepbound from the labels.GLP-1 heart rate and hypersensitivity warning
Mean bpm rises and anaphylaxis/angioedema wording from all 8 US labels and Canadian monographs.