Question 1

What is the difference between Wegovy and Zepbound?

Accepted Answer

Wegovy and Zepbound are both once-weekly injections FDA-approved for chronic weight management, but they use different molecules. Wegovy is semaglutide, made by Novo Nordisk, activating the GLP-1 receptor. Zepbound is tirzepatide, made by Eli Lilly, activating both GLP-1 and a second receptor called GIP. Wegovy also carries approvals for cardiovascular risk reduction in adults with heart disease and obesity, and for adolescents aged 12 and older. Zepbound is additionally approved for moderate-to-severe obstructive sleep apnea in adults with obesity. Dose ranges differ — Wegovy maintenance 2.4 mg (up to 7.2 mg for Wegovy HD), Zepbound up to 15 mg. Both are titrated gradually over months.

Question 2

Which causes more weight loss, Wegovy or Zepbound?

Accepted Answer

Zepbound produces more weight loss on average, based on the strongest evidence available. In SURMOUNT-5, a head-to-head randomized trial reported by Eli Lilly in May 2025, adults on Zepbound at their maximum tolerated dose lost approximately 20.2% of baseline body weight over 72 weeks, compared with 13.7% for adults on Wegovy at their maximum tolerated dose. Earlier single-drug trials showed similar patterns: SURMOUNT-1 for Zepbound and STEP 1 for Wegovy, though cross-trial comparisons have caveats. The likely mechanism for Zepbound's advantage is its dual receptor action. The gap is real but individual results still vary widely based on adherence, lifestyle, and starting weight.

Question 3

Can I switch between Wegovy and Zepbound?

Accepted Answer

Yes, and switching is common, with moves from Wegovy to Zepbound more frequent because of the efficacy advantage shown in SURMOUNT-5. The usual plan is to stop the current drug, wait about a week for it to clear, then start the new one at its lowest dose and titrate up — Zepbound at 2.5 mg weekly, Wegovy at 0.25 mg weekly. Doses do not translate between molecules, so your prescriber sets a new titration schedule. Expect gut symptoms to return during re-titration. Both drugs are labeled for weight management, so insurance pathways are similar, but each plan's formulary preference may favor one over the other. Never take both at the same time.

Question 4

Which has fewer side effects, Wegovy or Zepbound?

Accepted Answer

Trial data suggests Zepbound tolerates slightly better at equivalent dose steps, though both are in the same ballpark. Wegovy's STEP 1 rates run nausea 44%, diarrhea 30%, vomiting 24%, constipation 24%. Zepbound's SURMOUNT rates run nausea 24 to 33%, diarrhea 18 to 25%, vomiting 10 to 18%, constipation 13 to 17%. SURMOUNT-5 reported broadly similar tolerability between the two, with Zepbound showing slightly higher nausea at peak doses. Both carry the same thyroid-tumor boxed warning and share pancreatitis and gallbladder risks. Zepbound reports hair loss in about 5 to 6% of users, linked to rapid weight loss. Slow titration helps either drug.

Question 5

Is Wegovy or Zepbound cheaper?

Accepted Answer

Sticker prices are comparable — both fall in the typical brand-name GLP-1 range without insurance. Coverage is the main differentiator. Both are weight-management drugs, so plans that exclude weight-loss medications exclude both. Wegovy's March 2024 cardiovascular indication opened coverage for patients with heart disease. Zepbound's December 2024 obstructive sleep apnea indication created a similar pathway for patients with documented OSA. Medicare Part D does not cover either drug for weight loss alone under federal law, though patients with qualifying OSA or cardiovascular disease may find a route. Eli Lilly offers Zepbound vials through LillyDirect at reduced self-pay prices. Both manufacturers run savings cards for commercial patients.

Question 6

Are Wegovy and Zepbound the same drug?

Accepted Answer

No. Different active ingredients, different manufacturers, different mechanisms. Wegovy contains semaglutide (a GLP-1 receptor agonist) from Novo Nordisk. Zepbound contains tirzepatide (a dual GIP and GLP-1 receptor agonist) from Eli Lilly. Both are once-weekly subcutaneous injections approved for chronic weight management, which is why they are often compared, but they are not interchangeable. Semaglutide is also sold as Ozempic for diabetes and Rybelsus as a pill. Tirzepatide is also sold as Mounjaro for diabetes. The pens are different, the dose ranges are different, and the insurance processing is separate.

Question 7

Does it matter which one my doctor prescribes?

Accepted Answer

It can, depending on what you value. If maximum average weight loss matters most and both drugs are available to you, Zepbound has the edge based on SURMOUNT-5 — roughly 7 percentage points of additional body-weight loss over 72 weeks at top doses. If you have established cardiovascular disease, Wegovy's SELECT-trial approval for reducing major cardiovascular events gives it a specific indication Zepbound does not share. If you have obstructive sleep apnea, Zepbound's OSA approval gives it an indication Wegovy lacks. Insurance formularies often narrow the choice regardless. Tolerability varies person to person. Your prescriber can weigh these factors against your full medical picture.

Question 8

What did SURMOUNT-5 show about tirzepatide versus semaglutide?

Accepted Answer

SURMOUNT-5 was the first direct head-to-head trial comparing Zepbound against Wegovy for chronic weight management, with each drug titrated to the maximum tolerated dose (up to 15 mg weekly for tirzepatide, up to 2.4 mg for semaglutide). Eli Lilly reported results in May 2025. Over 72 weeks, Zepbound produced significantly greater total body-weight loss than Wegovy — approximately 20.2% versus 13.7%, a gap of roughly 47% more weight lost in relative terms. Tolerability was broadly similar, with slightly higher peak nausea on Zepbound. This is the strongest evidence to date that tirzepatide's dual-receptor action outperforms GLP-1-only therapy for weight reduction. The trial did not measure cardiovascular outcomes, which remain a unique strength of Wegovy's label through the SELECT trial.

Question 9

Should someone with heart disease choose Wegovy over Zepbound?

Accepted Answer

For patients with established cardiovascular disease and obesity or overweight, Wegovy currently has clearer evidence. The SELECT trial showed Wegovy 2.4 mg weekly reduced major adverse cardiovascular events — cardiovascular death, non-fatal heart attack, non-fatal stroke — by about 20% over a median 3.3 years. The FDA added that cardiovascular risk-reduction indication in March 2024. Zepbound does not yet have a cardiovascular outcomes trial published. Tirzepatide's cardiovascular outcomes trial (SURPASS-CVOT) is ongoing but its results have not been incorporated into the Zepbound label. Your cardiologist and prescribing physician should weigh this together, especially when both weight loss and heart-event prevention are goals.

Feature	Wegovy(semaglutide)	Zepbound(tirzepatide)
Active Ingredient	semaglutide	tirzepatide
Drug Class	GLP-1 receptor agonist	Dual GIP and GLP-1 receptor agonist
Manufacturer	Novo Nordisk	Eli Lilly
FDA Approved	2021-06-04	2023-11-08
Approved Indications	Chronic weight management in adults with BMI ≥30 or ≥27 with at least one weight-related comorbidity Chronic weight management in patients aged 12+ with BMI at 95th percentile or greater Reduction of risk of major adverse cardiovascular events (cardiovascular death, non-fatal MI, non-fatal stroke) in adults with established CVD and either obesity or overweight (March 8, 2024)	Chronic weight management in adults with BMI ≥30 or ≥27 with at least one weight-related comorbidity (adjunct to diet and exercise) Treatment of moderate-to-severe obstructive sleep apnea in adults with obesity (December 20, 2024)
Route	subcutaneous injection	subcutaneous injection
Frequency	Once weekly	Once weekly
Starting Dose	0.25 mg weekly	2.5 mg weekly
Maintenance Dose	2.4 mg weekly	5 mg, 10 mg, or 15 mg weekly
Max Dose	7.2 mg weekly (Wegovy HD, approved March 19, 2026)	15 mg weekly
Weight Loss (%)	16.9%	22.5%
A1C Reduction	N/A (not indicated for diabetes)	N/A (not indicated for diabetes)
Key Trial	STEP 1 (68 weeks)	SURMOUNT-1 / SURMOUNT-5 (head-to-head vs semaglutide) (72 weeks)
List Price	$1,349-$1,650/month	$1,060-$1,176/month
With Insurance	$25-$250/month (varies by plan; many plans exclude weight-loss drugs)	$25-$250/month (varies; weight-loss coverage is limited)
Savings Card	$0/month for eligible patients (NovoCare savings program)	$25/month (Lilly savings card, commercially insured)

Side Effect	Wegovy	Zepbound
Nausea	44%	24-33%
Diarrhea	30%	18-25%
Vomiting	24%	10-18%
Constipation	24%	13-17%
Abdominal pain	20%	10-14%
Headache	14%	Not reported
Fatigue	11%	Not reported
Pancreatitis (rare)	<1%	<1%
Gallbladder events	2.6%	1.6%
Dyspepsia	Not reported	7-10%
Injection site reaction	Not reported	3-7%
Hair loss	Not reported	5-6%

Wegovy vs Zepbound: Weight Loss, Heart Risk, and Sleep Apnea Compared

Summary

Wegovy vs Zepbound: Full Comparison

Side Effects: Wegovy vs Zepbound

Thinking of Switching?

Related Comparisons

Frequently Asked Questions

Sources & References

FDA & Regulatory

Clinical Trial Records

Peer-Reviewed Literature

Safety Communications

Manufacturer Information

Reference Entries

Additional References