Zepbound produces more weight loss on average (about 20% of body weight vs. 14% for Wegovy in head-to-head trials). It works on two hormone pathways instead of one. Wegovy has a longer track record, more cardiovascular outcome data, and is approved for adolescents 12 and older. Both are effective, have similar side effects, and work best when combined with lifestyle changes. If one doesn’t work well for you, we can switch to the other.
If you’re researching GLP-1 medications for weight loss, you’ve probably seen both Zepbound and Wegovy mentioned. They’re the two most effective FDA-approved weight loss medications available today.
At PEAK Wellness & Aesthetics, we prescribe both. The right choice depends on your goals, your health history, and what your insurance covers. This guide breaks down the real differences so you can have an informed conversation with your provider.
How they work: one hormone vs. two
The biggest difference between these medications is their mechanism of action.
Wegovy (semaglutide) mimics a single gut hormone called GLP-1. This hormone signals your brain that you’re full, reduces appetite, and slows down digestion. It’s been studied extensively and has strong clinical data.
Zepbound (tirzepatide) mimics two gut hormones: GLP-1 and GIP. These hormones work together — GIP appears to enhance the appetite-suppressing effects of GLP-1. Think of it as having two levers instead of one.
This dual mechanism is likely why Zepbound produces greater weight loss in clinical trials.
Weight loss: what the studies show
In 2025, the SURMOUNT-5 trial directly compared Zepbound and Wegovy head-to-head. This was the first trial to pit these medications against each other rather than against placebo.
Results at 72 weeks
| Outcome | Zepbound | Wegovy |
|---|---|---|
| Average weight loss | 20.2% | 13.7% |
| Average pounds lost | ~50 lbs | ~33 lbs |
| Achieved ≥15% loss | 64.6% | 40.1% |
| Achieved ≥25% loss | 31.6% | 16.1% |
| Waist circumference reduction | 7.2 inches | 5.1 inches |
Source: SURMOUNT-5 trial (2025). Results are averages — individual responses vary.
That’s a meaningful difference. Zepbound users lost about 47% more weight than Wegovy users in this trial.
However, individual results vary. Some patients do better on Wegovy. Some plateau on one medication and then respond well when switched to the other. The trial results are averages — your experience may be different. For a closer look at the data, see our breakdown of Zepbound weight loss results and our Wegovy treatment overview.
Side effects: similar profiles
Both medications cause similar side effects, mostly gastrointestinal. Nausea is the most common, especially early on. Diarrhea, constipation, vomiting, stomach pain, and fatigue also occur with both medications.
These side effects are usually mild to moderate and tend to improve as your body adjusts. They’re most common during the first few weeks and when your dose increases.
In the SURMOUNT-5 trial, slightly fewer patients discontinued Zepbound due to side effects compared to Wegovy (6.1% vs. 8.0%). But this difference isn’t large enough to say one is definitively better tolerated than the other.
Both medications carry a black box warning about thyroid C-cell tumors found in rodent studies. Neither is recommended for patients with a personal or family history of medullary thyroid cancer or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
Some patients tolerate one medication better than the other. If you’re having difficulty with side effects, switching is always an option.
Dosing: different schedules
Both are once-weekly injections, but the titration schedules differ.
| Timeline | Wegovy (semaglutide) | Zepbound (tirzepatide) |
|---|---|---|
| Weeks 1–4 | 0.25 mg | 2.5 mg |
| Weeks 5–8 | 0.5 mg | 5 mg |
| Weeks 9–12 | 1 mg | 7.5 mg |
| Weeks 13–16 | 1.7 mg | 10 mg |
| Weeks 17–20 | 2.4 mg (maintenance) | 12.5 mg |
| Week 21+ | — | 15 mg (maintenance) |
| Total dose steps | 5 steps over 16 weeks | 6 steps over 20 weeks |
Zepbound has a longer titration period and more dose options. This can be helpful if you need to stay at a middle dose due to side effects — you have more flexibility.
Wegovy’s slower initial escalation (starting at 0.25 mg) may make the first few weeks more tolerable for some patients.
FDA approvals: different strengths
Both medications are FDA-approved for chronic weight management in adults. But they have different additional approvals that may matter depending on your health history.
Wegovy is also approved for:
- Adolescents ages 12+ with obesity
- Reducing cardiovascular risk (heart attack, stroke, cardiovascular death) in adults with established heart disease who have obesity or are overweight
- Treating MASH (metabolic dysfunction-associated steatohepatitis) with moderate to advanced liver scarring
Zepbound is also approved for:
- Treating moderate to severe obstructive sleep apnea in adults with obesity
If you have heart disease and are concerned about cardiovascular risk, Wegovy has stronger outcome data for that indication. If you have sleep apnea, Zepbound has specific approval there.
Insurance coverage & cost
Insurance coverage for both medications requires prior authorization. Some plans cover one but not the other. Some cover neither.
Factors that affect coverage include your specific insurance plan and formulary, whether your employer excludes weight loss medications, your BMI and weight-related conditions, and whether you’ve tried lifestyle changes first.
At PEAK, we check your benefits before your first visit and help you understand which medication your plan is more likely to cover. If one is denied, we often try the other.
Cost without insurance
If you’re paying out of pocket, manufacturer self-pay programs may lower monthly medication costs for eligible patients. Pricing changes over time, and manufacturer savings programs typically can’t be used with government insurance (Medicare, Medicaid, TRICARE).
Learn more about insurance coverage for weight loss medications →
How to choose: a decision framework
- Maximum weight loss is your primary goal
- You’ve tried Wegovy and plateaued or had side effects
- You have obstructive sleep apnea
- Your insurance covers Zepbound better than Wegovy
- You have established cardiovascular disease and want proven CV risk reduction
- You’re an adolescent (12–17) with obesity
- Your insurance covers Wegovy better than Zepbound
- You have MASH (fatty liver disease with scarring)
The truth is, both medications are effective. The “best” choice depends on your individual situation — and sometimes you don’t know how you’ll respond until you try. For more guidance, see our article on how to choose a weight loss medication.
What if I start one and it doesn’t work?
Switching from Wegovy to Zepbound (or vice versa) is safe when done under medical supervision. Your dose may need to be adjusted during the transition.
We see patients who started on Wegovy but plateaued and did better on Zepbound, who had significant nausea on one medication but tolerated the other well, and who switched because of insurance coverage changes.
This is one reason working with a medical weight loss clinic matters. We can adjust your treatment plan based on how you’re actually responding — not just write a prescription and hope for the best.
Can I take both together?
No. You should not take Zepbound and Wegovy at the same time. They work on similar pathways, and combining them would increase side effects without additional benefit. You take one or the other.
