Zepbound vs Wegovy: Which One Actually Works Better?

Zepbound and Wegovy are both injectable weight-loss medications, but they contain different active drugs. Zepbound is the brand name for tirzepatide, a "dual agonist" that activates both the GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) receptors. Wegovy is the brand name for semaglutide, which activates GLP-1 receptors only. Both drugs work by slowing stomach emptying, reducing appetite signals in the brain, and improving how your body regulates blood sugar — but tirzepatide's added GIP activity appears to amplify the appetite-suppressing and metabolic effects. Zepbound is manufactured by Eli Lilly (the same active ingredient as Mounjaro, which is approved for diabetes); Wegovy is manufactured by Novo Nordisk (the same active ingredient as Ozempic, also approved for diabetes). Both are FDA-approved specifically for chronic weight management in adults with obesity, or overweight with a weight-related condition.

The clearest answer comes from SURMOUNT-5, the first trial to directly compare tirzepatide and semaglutide in the same study population rather than across separate trials. Published in 2025, SURMOUNT-5 randomized adults with obesity to either tirzepatide or semaglutide at maximum tolerated doses for 72 weeks. Participants on tirzepatide lost an average of 20.2% of body weight, compared to 13.7% on semaglutide — a gap of roughly 6.5 percentage points in tirzepatide's favor. This head-to-head result lines up with what indirect comparisons of the earlier SURMOUNT-1 (tirzepatide, Jastreboff et al., NEJM, 2022) and STEP 1 (semaglutide, Wilding et al., NEJM, 2021) trials had already suggested, but SURMOUNT-5 removed the guesswork by testing both drugs in the same trial design. For the full breakdown of that trial's methodology and results, see our [SURMOUNT-5 head-to-head deep dive](/blog/tirzepatide-vs-semaglutide-surmount-5-head-to-head).

Both drugs share the same class of side effects because both slow digestion: nausea, constipation, diarrhea, and occasional vomiting, especially during dose escalation. In SURMOUNT-5, gastrointestinal adverse events occurred at similar rates between the two arms, and discontinuation due to side effects was comparable. That said, individual response varies a lot — some people tolerate tirzepatide's dual mechanism better, while others find semaglutide gentler on the stomach. Injection site reactions, fatigue, and hair shedding during rapid weight loss are reported with both. Neither drug has a clear, consistent edge on tolerability in the data so far; the honest answer is that you often can't predict which one your body will handle better until you try it.

This is where Wegovy currently has an edge on paper. The SELECT trial (Lincoff et al., NEJM, 2023) followed over 17,000 adults with cardiovascular disease and overweight/obesity but without diabetes, and found semaglutide reduced major adverse cardiovascular events (heart attack, stroke, or cardiovascular death) by 20% compared to placebo. That result earned Wegovy an FDA label expansion for cardiovascular risk reduction — the first weight-loss drug to receive one. Tirzepatide has strong cardiometabolic data (improvements in blood pressure, lipids, and inflammatory markers across the SURMOUNT program), and dedicated cardiovascular outcomes trials are underway, but as of now it doesn't carry the same FDA-approved heart-protection indication. If reducing cardiovascular risk is your top priority and you have established heart disease, this is a meaningful point in Wegovy's favor to discuss with your prescriber — independent of which drug produces more scale-weight loss.

Neither drug is reliably "cheaper" in the abstract — list prices for both run over $1,000 per month without insurance, though manufacturer savings programs, direct-pay options, and 2026 pricing changes have shifted the landscape (see our guide to [direct-pay GLP-1 pricing](/blog/glp1-direct-pay-pricing-2026-lillydirect-novocare-trumprx)). The bigger factor is usually your specific insurance formulary: some plans cover Zepbound but not Wegovy, or vice versa, based on manufacturer rebate deals that change year to year. Before assuming one drug is "better" for you, it's worth calling your insurer or checking your formulary — a covered drug you can actually afford and stay on consistently will outperform an uncovered one you have to stop. If you hit a denial, our guide on [appealing a GLP-1 prior authorization denial](/blog/glp1-insurance-denial-how-to-appeal-prior-authorization-2026) walks through the process.

Start with what your insurance covers — that often narrows the choice for you. If both are accessible, consider your priorities: if maximum average weight loss is the deciding factor, the data currently favors Zepbound. If you have established cardiovascular disease and want an FDA-backed heart-protection indication, Wegovy has the edge. If you've already tried one and had significant side effects, switching to the other is a reasonable next step — many people who don't tolerate semaglutide well do fine on tirzepatide, and vice versa. Dose escalation speed also matters more than the drug itself for how rough the first few months feel; our guide on [when to increase your dose and when to hold](/blog/glp1-dose-escalation-when-to-increase-and-when-to-hold) covers how to pace that conversation with your prescriber.

Every body responds differently to GLP-1 medications, and the right choice depends on your health history, side-effect tolerance, and coverage — not just trial averages. Lea can help you think through the tradeoffs based on what matters most to you.