This is a summary of public information, not medical advice. A prescriber can go through the full prescribing information and your own risks.
Most common side effects
Reported rates in the main weight-loss trials (approximate, drug vs placebo):
| Side effect | Wegovy 2.4 mg | Zepbound (by dose) |
|---|---|---|
| Nausea | ~44% vs 16% | ~25–29% vs 9% |
| Diarrhea | ~30% vs 16% | ~19–23% vs 9% |
| Vomiting | ~24% vs 6% | ~8–13% vs 2% |
| Constipation | ~24% vs 11% | ~11–17% vs 7% |
Trials differ in design, so these numbers aren't a direct head-to-head comparison. In pooled Wegovy trials, 6.8% of people stopped treatment because of side effects, compared with 3.2% on placebo.
Label warnings
The labels for these medications include warnings that a prescriber reviews with patients, including:
- A boxed warning about thyroid C-cell tumors seen in rodent studies. They are not for people with a personal or family history of medullary thyroid cancer or MEN2.
- Pancreatitis and gallbladder problems.
- Low blood sugar, mainly when combined with insulin or sulfonylureas.
- Kidney problems linked to dehydration from vomiting or diarrhea.
- Possible risks with anesthesia or sedation because of slowed stomach emptying.
When to contact a clinician
The labels advise contacting a healthcare provider for severe stomach pain that won't go away, signs of an allergic reaction, a lump or swelling in the neck, or persistent vomiting. In an emergency, call 911.
Compounded versions
Compounded GLP-1s are not FDA-approved, so their side-effect profile has not been studied in the same way. More on compounded GLP-1s.
Sources
- Wegovy prescribing information
- Wegovy adverse reactions (Novo Nordisk)
- Zepbound prescribing information
GLP1Rated is for general information only and is not medical advice. GLP-1 medications are prescription drugs with real risks and side effects. Talk to a licensed clinician before starting, stopping or changing any medication or supplement.