Mounjaro vs Wegovy

Editorial comparison of Mounjaro (tirzepatide) and Wegovy (semaglutide). Same drug class context, trial-anchored data, no marketing claims.

Reviewed by the WeighedHealth Editorial Team against primary clinical sources — FDA labeling, peer-reviewed trials, and specialty-society guidelines.

Content current as of July 2026; updated when guidance or availability changes.

Side-by-side

Dimension	Mounjaro	Wegovy
Generic name	tirzepatide	semaglutide
Manufacturer	Eli Lilly	Novo Nordisk
FDA approved	2022	2021
Mechanism	Same as Zepbound — dual GLP-1/GIP receptor agonist. Strong glycemic effect plus weight loss.	Semaglutide mimics GLP-1, a gut hormone released after meals.
Dosing	Titrated 2.5mg → 15mg weekly over months, same schedule as Zepbound.	Titrated over 4-5 months: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg, increasing every 4 weeks.
Cost	Similar to Zepbound — list ~$1,000/month, LillyDirect Self-Pay $399-549/month.	List price ~$1,350/month without insurance.
Pivotal trial result	2.0–2.3% HbA1c reduction across SURPASS trials (15 mg dose)	14.9% mean body-weight reduction at 68 weeks

Efficacy in the trials

Mounjaro

2.0–2.3% HbA1c reduction across SURPASS trials (15 mg dose)

SURPASS-2 (NCT03987919) — vs semaglutide · Tirzepatide 15 mg achieved 2.30% HbA1c reduction vs 1.86% for semaglutide 1 mg · n=1,879

Wegovy

14.9% mean body-weight reduction at 68 weeks

STEP 1 (NCT03548935) · vs 2.4% with placebo + lifestyle · n=1,961

Trial averages describe study populations, not individuals. Response varies with the dose tolerated, adherence, and personal physiology; the two drugs were not necessarily tested head-to-head in the same trial.

The details

Dosing & cadence

Mounjaro: Titrated 2.5mg → 15mg weekly over months, same schedule as Zepbound.

Wegovy: Titrated over 4-5 months: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg, increasing every 4 weeks. Maintenance dose 2.4mg weekly. Slower titration is common to manage GI side effects.

Cost & access

Mounjaro: Similar to Zepbound — list ~$1,000/month, LillyDirect Self-Pay $399-549/month.

Wegovy: List price ~$1,350/month without insurance. With Novo Nordisk's patient assistance program, eligible self-pay patients can access at $200-500/month. Insurance coverage is patchy and often requires prior authorization plus a documented weight-related comorbidity.

Side effects

Mounjaro: Same as Zepbound.

Wegovy: Most common: nausea (especially first 4-8 weeks), constipation, diarrhea, fatigue, headache. Less common: gallbladder issues, pancreatitis (rare), kidney strain if dehydrated. Black-box warning: medullary thyroid cancer risk (theoretical, based on rodent studies). Discontinue and consult clinician for severe abdominal pain or persistent vomiting.

Which should you choose?

If maximizing average trial weight loss is the priority, Wegovy posted the higher pivotal-trial figure; Mounjaro still produced clinically meaningful loss and some people tolerate it better. On cost and access, compare each drug's manufacturer direct-pay and insurance path — that often matters more month-to-month than the efficacy gap. Both carry class safety considerations (see each drug's boxed-warning and contraindications); a personal or family history of medullary thyroid carcinoma or MEN2 rules out the GLP-1 class. Bring this comparison to a prescriber, who will match the drug to your history and titrate the dose.

This is editorial framing, not a prescription. The right choice depends on your medical history, insurance, and a clinician's evaluation.

Full Mounjaro review →

FDA-approved tirzepatide for type 2 diabetes. Off-label for weight loss is common.

Full Wegovy review →

Once-weekly injectable semaglutide for chronic weight management. ~15% body weight loss in trials.

Deciding at the molecule level? Semaglutide vs Tirzepatide compares the two drug families behind every major GLP-1 brand.

Frequently asked

Is Mounjaro or Wegovy more effective?+

In their pivotal trials, Mounjaro reported 2.0–2.3% HbA1c reduction across SURPASS trials (15 mg dose), while Wegovy reported 14.9% mean body-weight reduction at 68 weeks. Head-to-head results vary by patient profile, dose tolerated, and adherence — these trial numbers describe averages, not what every individual experiences.

How do Mounjaro and Wegovy compare on cost?+

Mounjaro: Similar to Zepbound — list ~$1,000/month, LillyDirect Self-Pay $399-549/month. Wegovy: List price ~$1,350/month without insurance. With Novo Nordisk's patient assistance program, eligible self-pay patients can access at $200-500/month. Insurance coverage is patchy and often requires prior authorization plus a documented weight-related comorbidity. Real out-of-pocket depends on insurance formulary tier, manufacturer savings programs, and whether a direct-pay channel is available.

Can I switch from Mounjaro to Wegovy?+

Switching between brand-name treatments in the same drug class is common, but the conversion is not always 1:1. Discuss the switch with your prescriber — they'll usually re-titrate dosing rather than substitute equivalent strengths directly.

Are Mounjaro and Wegovy the same drug?+

No. Mounjaro (tirzepatide) and Wegovy (semaglutide) are distinct medications from Eli Lilly and Novo Nordisk respectively. They may share a drug class or mechanism but differ in active ingredient, dosing, and approved use.