Wegovy vs. Zepbound: What the FDA Labels Actually Say
Two different drugs, two different approval lists, and one shared warning you need to read.
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Most people comparing these two drugs are reading Reddit threads and TikTok takes. Here's what the actual FDA labels say — and what they don't.
Wegovy (semaglutide, made by Novo Nordisk) and Zepbound (tirzepatide, made by Eli Lilly) are the two heavyweights in prescription weight management right now. They're both injected weekly. They both require a reduced-calorie diet and more physical activity. And they both have long warning lists that most people skip straight past.
But they are not the same drug, and the FDA didn't approve them for the same things.
What the FDA Actually Approved Each Drug For
The FDA's Wegovy label lists four distinct indications. The big two are weight reduction in adults and adolescents aged 12+ with obesity, and weight reduction in adults who are overweight with at least one weight-related condition. But Wegovy also carries FDA approval to reduce the risk of major cardiovascular events — heart attack, stroke, and CV death — in adults with established cardiovascular disease and obesity or overweight. That's a meaningful clinical distinction. And as of its most recent label update, Wegovy injection has also received accelerated approval for metabolic dysfunction-associated steatohepatitis (MASH) with moderate-to-advanced liver fibrosis in adults — though the FDA notes that continued approval may depend on confirmatory trial results.
The FDA's Zepbound label covers weight reduction in adults with obesity or overweight with a comorbidity — same core indication. But Zepbound's second approval is different: it's indicated to treat moderate-to-severe obstructive sleep apnea (OSA) in adults with obesity. If sleep apnea is part of your picture, that's a label distinction worth knowing.
How the Drugs Work — and Why It Matters
Wegovy is a GLP-1 receptor agonist. It mimics one gut hormone that slows gastric emptying, reduces appetite, and nudges your pancreas to release insulin in a glucose-dependent way.
Zepbound is a dual GIP and GLP-1 receptor agonist — it targets two receptors simultaneously. GIP (glucose-dependent insulinotropic polypeptide) is a second gut hormone that may amplify the metabolic effects. Whether that dual action is why tirzepatide tends to show larger weight loss numbers in trials is still being studied, but the mechanism is genuinely different.
A 2024 real-world study published in JAMA Internal Medicine compared semaglutide and tirzepatide in adults with overweight or obesity and found tirzepatide was associated with greater weight loss at one year. A 2025 systematic review in Diabetes, Metabolism and Syndrome comparing Phase 3 clinical trial data reached a similar conclusion on efficacy, while noting the safety profiles were broadly comparable. These are reported associations from studies — not a guarantee of what you will experience.
The Shared Warning List (Read This Part)
Both labels carry a boxed warning about thyroid C-cell tumors observed in rodent studies. Neither drug is recommended for people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2.
Beyond that, the FDA's Wegovy label and Zepbound label both warn about:
- Acute pancreatitis — discontinue if suspected
- Acute gallbladder disease — gallstones have been reported in clinical trials
- Acute kidney injury from dehydration caused by GI side effects
- Hypoglycemia — especially if you're also on insulin or a sulfonylurea
- Hypersensitivity reactions including anaphylaxis, reported post-marketing
- Pulmonary aspiration risk during general anesthesia or deep sedation
Both labels also flag diabetic retinopathy complications for patients with type 2 diabetes and a history of retinopathy.
The most commonly reported side effects (≥5% in trials) are nearly identical for both: nausea, diarrhea, vomiting, constipation, abdominal pain, fatigue, hair loss, and GERD. These are adverse event reports from clinical trials — not confirmed rates that apply to every person.
Where the Labels Diverge on Warnings
Wegovy's label adds a specific caution around heart rate increases and recommends monitoring at regular intervals. It also flags dysesthesia (abnormal skin sensations) as a commonly reported adverse reaction — something that doesn't appear as prominently in Zepbound's label language.
Zepbound's label, meanwhile, explicitly states that co-administration with any other GLP-1 receptor agonist is not recommended — a practical note if you're ever switching between drugs or considering combination approaches.
What This Means for You
- The FDA approved these drugs for overlapping but not identical conditions. Wegovy has a cardiovascular risk-reduction indication and a MASH indication; Zepbound has an obstructive sleep apnea indication. Those differences matter if you have those specific conditions.
- Both share the same core warning profile. Thyroid tumor history, pancreatitis risk, gallbladder disease, GI side effects — these aren't brand-specific concerns, they're class-wide ones worth discussing with your prescriber.
- Real-world and trial data suggest tirzepatide may produce greater average weight loss, but individual response varies, insurance coverage varies, and the drug that works best is the one you can access, tolerate, and stay on.
Not medical advice. Talk to your prescriber about your specific health history, conditions, and which option — if either — is appropriate for you.
