Wegovy vs Zepbound: Which Weight-Loss GLP-1 Is Right for You? (2026)

Wegovy® and Zepbound® are the two FDA-approved medications built specifically for chronic weight management — and for most people choosing between them, it's the single biggest decision in their treatment plan. Both are once-weekly injections. Both suppress appetite. Both have been studied in tens of thousands of patients, including head-to-head. But they're different molecules, made by different manufacturers, produce different amounts of weight loss, and are priced differently.

Here's what the clinical evidence actually shows, side by side.

Quick comparison

Both are FDA-approved, cash-pay through Pallas; not billed to insurance.

How they work

Both medications mimic natural gut hormones released after eating — but Zepbound® mimics two of them, which is why it tends to be more effective.

Wegovy® (semaglutide) is a GLP-1 (glucagon-like peptide-1) receptor agonist. When you eat, your gut releases GLP-1, which signals fullness to your brain, slows stomach emptying, and prompts insulin release. Semaglutide mimics GLP-1 but lasts far longer than the natural hormone — a single weekly injection holds steady levels.

Zepbound® (tirzepatide) is a dual agonist. It activates the same GLP-1 receptor as semaglutide, plus a second receptor called GIP (glucose-dependent insulinotropic polypeptide), another gut hormone involved in fat metabolism and energy balance. Hitting both receptors produces stronger appetite suppression and greater average weight loss.

For a deeper look at the receptor biology behind both, read our explainer on how GLP-1 and GIP work.

Effectiveness: what the trials showed

Each drug has its own pivotal trial, and — unusually — they've also been compared directly.

STEP-1 (Wegovy®, semaglutide 2.4 mg weekly):

• Average weight loss: 14.9% of body weight at 68 weeks
• 50% of participants lost at least 15%
• 32% lost at least 20%

SURMOUNT-1 (Zepbound®, tirzepatide 15 mg weekly):

• Average weight loss: 20.9% of body weight at 72 weeks
• 57% of participants lost at least 20%
• 36% lost at least 25%

SURMOUNT-5 (head-to-head, 2025): In the first direct randomized comparison, participants on tirzepatide lost an average of ~20.2% of body weight versus ~13.7% on semaglutide at 72 weeks — a clear edge for Zepbound® in the same study. This is the strongest evidence to date that, on average, tirzepatide produces more weight loss than semaglutide.

For a 220-lb starting weight, that's roughly 30 lbs on Wegovy® vs 44 lbs on Zepbound® at the SURMOUNT-5 averages. The weight loss projection calculator will model your specific starting point against either curve. Averages are not guarantees — individual response varies widely, and both are highly effective.

Dosing and titration

Both must start low and increase gradually to minimize side effects — mostly nausea. Titrating too fast is the most common reason people quit in the first month.

Wegovy® titration:

1. Weeks 1–4: 0.25 mg
2. Weeks 5–8: 0.5 mg
3. Weeks 9–12: 1.0 mg
4. Weeks 13–16: 1.7 mg
5. Week 17+: 2.4 mg (maintenance)

Zepbound® titration:

1. Weeks 1–4: 2.5 mg
2. Weeks 5–8: 5 mg
3. Weeks 9–12: 7.5 mg
4. Weeks 13–16: 10 mg
5. Weeks 17–20: 12.5 mg
6. Week 21+: 15 mg (maintenance)

Many patients reach their goal at a lower dose and never need the maximum. Your provider adjusts titration based on how you tolerate each step.

Side effects compared

The profiles are very similar — both share the GLP-1 mechanism. The difference is mostly intensity, since greater weight loss tends to come with greater GI effects.

Most common (both, 20–40% of users in trials):

• Nausea (typically 1–4 weeks after each dose increase)
• Constipation
• Diarrhea
• Vomiting
• Abdominal discomfort

Less common but worth knowing:

• Fatigue (first few weeks)
• Loss of appetite to the point of under-eating (monitor protein)
• Injection-site reactions (minor redness)
• Gallbladder issues (~1% of users; risk rises with rapid weight loss)

Rare but serious (carry boxed warnings):

• Pancreatitis
• Thyroid C-cell tumors (based on animal studies; not conclusively linked in humans)
• Severe allergic reactions

Most GI side effects resolve within 4–8 weeks of starting or after each titration step. For a deeper look, read our complete guide to GLP-1 side effects.

Cost comparison

Usually the deciding factor for anyone paying out of pocket.

Brand-name pricing (without insurance)

With insurance coverage these can drop to $25–150/month, but weight-loss coverage (non-diabetic indication) is inconsistent. Most commercial plans still don't cover weight-loss GLP-1s, and Medicare is prohibited by law from covering anti-obesity medications. Both manufacturers now run direct self-pay programs that meaningfully lower cash costs at lower doses.

Compounded alternatives

When a licensed clinician determines a brand-name product isn't clinically appropriate for a specific patient, compounded semaglutide and tirzepatide are available through US-licensed compounding pharmacies at lower cost. At Pallas, compounded semaglutide injection is $269/mo and compounded tirzepatide injection is $359/mo, with lower microdose tiers — all cash-pay, with provider visits, dose adjustments, and shipping included.

Which one should you choose?

There's no universally right answer — but there are patterns.

Zepbound® tends to be the better fit if:

• You have a significant amount of weight to lose (40+ lbs)
• You want the highest average weight loss the evidence supports
• Semaglutide hasn't worked well for you in the past
• A slightly longer titration to maximum dose is fine

Wegovy® tends to be the better fit if:

• Your goal is more moderate (20–30 lbs)
• You want the medication with the longest post-market safety record (approved 2 years earlier)
• You're sensitive to medication effects and prefer fewer titration steps
• Your insurance happens to cover semaglutide but not tirzepatide (or vice versa)

Either works if:

• Your prescriber recommends one based on your health history
• Cost or your specific plan's formulary drives the decision

Ultimately a licensed clinician should make the call with you based on your medical history, goals, and tolerance.

Frequently asked questions

Is Zepbound® better than Wegovy®? On average, Zepbound® (tirzepatide) produces more weight loss — the head-to-head SURMOUNT-5 trial showed ~20.2% vs ~13.7% at 72 weeks. But "better" depends on your goals, tolerance, insurance, and history. Wegovy® has a longer safety track record and a shorter titration. Both are highly effective FDA-approved options.

Can I switch from Wegovy® to Zepbound®? Yes. Patients who plateau on Wegovy® or want greater loss often switch. Your provider designs a transition schedule — typically stopping one and starting the other at its lowest dose the following week.

Do they cost the same? Roughly, at list price (~$1,300–$1,400/month without insurance). Self-pay programs differ: Lilly's LillyDirect offers Zepbound® vials from ~$349/month at lower doses; Novo Nordisk's NovoCare offers Wegovy® self-pay around $499/month. Coverage and copays vary by plan.

Does insurance cover either one? Coverage varies enormously. Most commercial plans cover the diabetes versions (Ozempic®, Mounjaro®) but not the weight-loss versions (Wegovy®, Zepbound®). Medicare does not cover anti-obesity medications. Check your specific plan's formulary for weight-loss indications.

Can I take either during pregnancy? No. GLP-1 medications are contraindicated during pregnancy. People of reproductive age using these medications should use effective contraception and discuss timing with their provider if planning pregnancy.

Are these the same as the diabetes versions? Same molecules, different brands and indications. Wegovy® and Ozempic® are both semaglutide (Novo Nordisk); Zepbound® and Mounjaro® are both tirzepatide (Eli Lilly). The weight-loss brands (Wegovy®, Zepbound®) carry higher dose ceilings and obesity indications.

Bottom line: Zepbound® produces more weight loss on average — including head-to-head — while Wegovy® has a longer safety record and a shorter titration. Both are excellent FDA-approved options. The right choice depends on your goals, tolerance, insurance, and your clinician's judgment. It takes about 2 minutes to start the intake.