The current FDA labels for Wegovy, Zepbound and Foundayo each say the medicine lowers blood glucose and can cause hypoglycemia (low blood sugar), and each points to the same practical issue: the risk is higher when the medicine is combined with insulin or a sulfonylurea-type drug. The labels say a lower dose of the insulin or sulfonylurea may reduce that risk, and that people with diabetes should have their blood glucose monitored. Whether and how to adjust a diabetes medicine is a decision for your prescriber, not something to do on your own.
What the labels actually say
Hypoglycemia sits in the Warnings and Precautions section of each label, under a different number in each.
The Wegovy label (revised 06/2026), section 5.4, states that Wegovy lowers blood glucose and can cause hypoglycemia. It says the risk rises when semaglutide is used with insulin or an insulin secretagogue such as a sulfonylurea, tells clinicians to consider reducing the dose of the insulin or secretagogue when starting Wegovy, and says to counsel patients on the signs of low blood sugar and to monitor blood glucose in people with diabetes. The label also notes Wegovy has not been evaluated in type 1 diabetes or alongside insulin.
The Zepbound label (revised 08/2026), section 5.7, says Zepbound lowers blood glucose and can cause hypoglycemia, tells clinicians to monitor blood glucose before and during treatment in patients with diabetes, and says the risk of hypoglycemia may be lowered by a reduction in the dose of insulin or sulfonylurea.
The Foundayo label (orforglipron tablets, revised 07/2026), section 5.5, carries the same wording about lowering the dose of insulin or a sulfonylurea to reduce the risk.
What the trials in the labels report
The Wegovy label reports that in its trial in adults with type 2 diabetes and excess weight, clinically significant hypoglycemia (glucose below 54 mg/dL) occurred in 6.2% of Wegovy-treated patients versus 2.5% of those on placebo, and that one Wegovy-treated patient had a severe episode requiring intravenous glucose while no placebo patient did.
The Zepbound label reports that in its type 2 diabetes study, hypoglycemia was reported in 4.2% of Zepbound-treated patients versus 1.3% of placebo-treated patients, and that hypoglycemia was not systematically captured in the study of people without diabetes.
These figures come from different trials with different designs and definitions, so they should not be lined up as a head-to-head comparison between brands. They show direction (more events than placebo in people with diabetes), not a rate you should expect for yourself.
Why the combination with insulin or sulfonylureas matters
Insulin and sulfonylureas are themselves glucose-lowering drugs. When one of them is combined with a GLP-1 medicine, the labels indicate the chance of hypoglycemia is higher, which is why both the Wegovy and Zepbound labels single out dose reduction of those partner drugs as the lever to discuss with your prescriber.
Symptoms worth knowing
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists common signs of low blood glucose, including shakiness, hunger, fatigue, dizziness, confusion or irritability, a racing or irregular heartbeat, headache, and blurred vision or trouble speaking clearly. It says that when glucose is very low the brain may stop working as it should, leading to loss of consciousness or seizure, and that severe hypoglycemia needs to be treated right away. Because nausea and reduced appetite are also common with GLP-1 medicines, eating less than usual after a dose may be part of why a low occurs in someone already on glucose-lowering drugs. That is an inference to raise with your prescriber, not a finding from the labels.
What to do
- Tell your prescriber about every diabetes medicine you take before starting, especially insulin and any sulfonylurea.
- Ask for a written plan for what to check, how often, and what to do if a reading is low.
- Do not change an insulin or sulfonylurea dose yourself. The labels describe dose reduction as a clinician decision.
- Treat a severe episode as urgent. Seek emergency care for confusion, fainting or seizure.
Questions to ask your prescriber
- Do my current diabetes medicines raise the chance of a low when I add a GLP-1?
- Should my insulin or sulfonylurea dose change when I start, and when would we review it?
- How often should I check my glucose in the first weeks?
- What reading or symptom means I should call you the same day?
Hypoglycemia is one of several label warnings worth reading before starting. See our companion guides on dehydration and acute kidney injury, pancreatitis, diabetic retinopathy, and surgery and anesthesia.
Common misunderstandings
- “GLP-1 medicines never cause low blood sugar.” The labels say they can, and the risk is higher alongside insulin or sulfonylureas.
- “This only matters if you have diabetes.” The label statements about dose reduction and glucose monitoring apply to people with diabetes; the Zepbound label notes hypoglycemia was not systematically captured in its non-diabetes study.
- “I can just cut my insulin myself.” Adjustments should be made with your prescriber.
Questions people ask
Does the label give a single hypoglycemia rate for each medicine?
No. The labels report trial-specific figures, and the trials differ, so the numbers are not interchangeable.
Is orforglipron (Foundayo) treated differently?
In the label sections we reviewed, Foundayo carries the same instruction about lowering insulin or sulfonylurea doses. We did not find a separate trial rate for it in the sections reviewed.
When is low blood sugar an emergency?
Confusion, fainting, seizure or being unable to treat yourself calls for emergency care.
Sources
- U.S. FDA labeling, Wegovy prescribing information (revised 06/2026), sections 5.4 and 6.1, checked 8 October 2026.
- U.S. FDA labeling, Zepbound prescribing information (revised 08/2026), sections 5.7 and 6.1, checked 8 October 2026.
- U.S. FDA labeling, Foundayo prescribing information (revised 07/2026), section 5.5, checked 8 October 2026.
- NIDDK, Low Blood Glucose (Hypoglycemia).
Medical disclaimer. This article is informational and is not medical advice. Do not start, stop or change a prescribed medicine, including insulin or a sulfonylurea, without instructions from your prescriber. For confusion, fainting or seizure, seek emergency care.
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