Two GLP-1 based medications are currently FDA-approved specifically for chronic weight management: Wegovy (semaglutide) and Zepbound (tirzepatide). Both are weekly injections, and both require a reduced-calorie diet and increased physical activity alongside the medication. Other brand names you may have heard of, like Ozempic and Mounjaro, contain the same active ingredients but are approved only for type 2 diabetes, not weight loss.
Wegovy and Zepbound: The Two Approved Options
Wegovy, made by Novo Nordisk, was the first GLP-1 receptor agonist approved for weight management. Its active ingredient, semaglutide, is the same compound found in Ozempic, but Wegovy is dosed higher (up to 2.4 mg weekly compared to Ozempic’s typical maximum of 1 mg) and carries the specific FDA indication for weight loss.
Zepbound, made by Eli Lilly, received FDA approval for chronic weight management in November 2023. Its active ingredient, tirzepatide, is also found in Mounjaro, which is approved only for type 2 diabetes. Zepbound works slightly differently from Wegovy because it activates two receptors instead of one: GLP-1 and GIP. This dual action targets appetite through multiple pathways, and in clinical trials, tirzepatide produced greater average weight loss than semaglutide alone.
How These Medications Work
GLP-1 is a hormone your gut naturally releases after eating. It signals your brain to feel full, slows the rate at which food leaves your stomach, and triggers insulin release. Both Wegovy and Zepbound mimic this hormone, but they stay active in your body far longer than natural GLP-1, which breaks down within minutes.
Zepbound adds a second mechanism through GIP, another gut hormone that influences energy balance. GIP acts on the brain and fat tissue to reduce food intake and regulate how your body stores dietary fat. The combination of both signals appears to suppress appetite more effectively than targeting GLP-1 alone.
The practical result of both medications is that you feel less hungry, feel satisfied sooner when eating, and think about food less often throughout the day. This makes it significantly easier to sustain a calorie deficit without the constant willpower struggle that derails most diets.
Who Qualifies for a Prescription
The FDA approval criteria are the same for both Wegovy and Zepbound. You’re eligible if you have a BMI of 30 or higher, which qualifies as obesity. You can also qualify with a BMI of 27 or higher if you have at least one weight-related health condition, including:
- Type 2 diabetes
- High blood pressure
- High cholesterol
- Obstructive sleep apnea
- Cardiovascular disease
- MASH (metabolic dysfunction-associated steatohepatitis), a form of liver inflammation
For reference, a BMI of 30 translates to roughly 180 pounds at 5’5″ or 210 pounds at 5’9″. A BMI of 27 is about 162 pounds at 5’5″ or 190 pounds at 5’9″.
Why Ozempic and Mounjaro Aren’t the Same Thing
This is one of the most common points of confusion. Ozempic and Wegovy both contain semaglutide. Mounjaro and Zepbound both contain tirzepatide. The difference is the FDA indication, the approved dosing, and the label. When a doctor prescribes Ozempic or Mounjaro for weight loss, that’s considered off-label use. It’s legal, and doctors do it, but insurance coverage is often different for off-label prescriptions, and the dosing may not match what was studied in weight-loss trials.
Wegovy is titrated from 0.25 mg up to 2.4 mg weekly over 16 to 20 weeks. Zepbound starts at 2.5 mg and increases in 2.5 mg steps every four weeks up to a maximum of 15 mg. Both use a gradual dose escalation to reduce side effects, so you won’t start at the full dose.
What to Expect From Side Effects
Gastrointestinal symptoms are the most common issue with both medications. Nausea, vomiting, diarrhea, and constipation affect roughly 50% to 60% of people during the initial phase of treatment. These side effects are dose-dependent, meaning they tend to flare when your dose increases, and they generally ease over time as your body adjusts. The gradual titration schedule exists specifically to minimize this.
Both medications carry an FDA boxed warning, the most serious type of drug warning. They should not be used by anyone with a personal or family history of medullary thyroid carcinoma or a condition called Multiple Endocrine Neoplasia syndrome type 2. This warning is based on findings in animal studies, and your prescriber will ask about thyroid cancer history before writing a prescription.
Ozempic and Mounjaro Are Not Approved Alternatives
If cost or availability is pushing you toward Ozempic or Mounjaro as a workaround, it’s worth understanding what you’re trading off. The diabetes versions are sometimes easier to get, and they may be cheaper depending on your insurance. But the weight-loss versions were studied at higher doses in obesity-specific trials, and their labeling reflects the safety and efficacy data for that specific use. If your goal is weight management rather than blood sugar control, the on-label option gives you and your doctor the clearest evidence base to work from.
How Much Weight Loss to Expect
Results vary, but clinical trials offer a useful baseline. In the trials that led to Wegovy’s approval, participants lost an average of about 15% of their body weight over roughly 68 weeks. Zepbound trials showed higher average weight loss, with many participants reaching 20% or more. For someone starting at 250 pounds, that translates to roughly 37 to 50 pounds or more, depending on the medication and individual response.
These numbers reflect averages across large groups of people who also followed a reduced-calorie diet and exercised. Some people lose significantly more, others less. Weight loss typically continues for about a year to 18 months before leveling off, and maintaining the loss generally requires staying on the medication long-term. Most studies show substantial weight regain after stopping treatment.
What’s Coming Next
Novo Nordisk submitted CagriSema to the FDA in December 2025. This medication combines semaglutide (the active ingredient in Wegovy) with a second compound that mimics amylin, another hormone involved in appetite and blood sugar regulation. In a 68-week trial, people on CagriSema lost 14.2% of their body weight compared to 10.2% for semaglutide alone, with 24% of participants reaching 20% or greater weight loss. Notably, weight loss had not plateaued by the end of the trial, suggesting the full effect may extend beyond 68 weeks. If approved, it would become a third option in this drug class.