Wegovy vs Zepbound: How to Choose the Right GLP-1 for You

Wegovy and Zepbound are the two FDA-approved injectable medications for chronic weight management, and they are the two names a good clinician weighs first. They are genuinely different medicines, not two brands of the same thing — and the difference matters both for how much weight people lose on average and for how the choice actually gets made in practice.

The mechanism difference

Wegovy is semaglutide: a GLP-1 receptor agonist. It mimics one gut hormone that curbs appetite and slows gastric emptying. Zepbound is tirzepatide: a dual agonist that acts on both the GLP-1 receptor and a second receptor, GIP. That second pathway is the leading explanation for why tirzepatide tends to produce larger average weight loss in trials — it is pulling two levers instead of one.

What the trials actually showed

In the STEP 1 trial, adults on semaglutide 2.4 mg lost about 15% of body weight on average over 68 weeks. In SURMOUNT-1, adults on the highest tirzepatide dose lost roughly 20 to 22% over 72 weeks. Those are averages from controlled trials — real-world results vary widely with dose tolerance, adherence, nutrition, and starting point. A trial average is a useful comparison, not a promise about any one person.

Side effects: more alike than different

Both medicines share the same core side-effect profile — nausea, constipation, fatigue, and other GI symptoms that concentrate in the first weeks and after dose increases. Tirzepatide can bring somewhat more GI effect for some patients alongside its stronger appetite suppression. In practice, how you tolerate titration matters more than the label; our guide to managing GLP-1 side effects covers the levers that keep either medication comfortable.

How the choice actually gets made

On paper Zepbound often shows bigger numbers. In the exam room the decision is rarely that simple. Insurance formularies frequently cover one and not the other. Prior authorization requirements differ. Your history with a previous GLP-1, your tolerance, and your specific goal all weigh in. And out-of-pocket cost — via manufacturer self-pay programs or a vetted compounded option — is often the deciding factor. Our breakdown of what GLP-1 therapy costs per month walks through that math.

This is exactly the kind of decision that should be made by a provider who knows your case, not chosen from a drop-down menu. At Elysiv, your assigned NP prescribes whichever medication is clinically right for you and titrates the dose around how your body actually responds — then adjusts as the picture changes.