G
GLP1Calc

Zepbound vs Mounjaro

Side-by-side comparison based on SURMOUNT-1 and SURPASS-2 / off-label phase 3 trial data plus April 2026 pricing.

Zepbound
tirzepatide (injection)
Higher efficacy
Peak weight loss22.5%
TrialSURMOUNT-1
Administrationinjection
FDA statusweight-loss
List price$1,059/mo
Mounjaro
tirzepatide (injection)
Peak weight loss20.9%
TrialSURPASS-2 / off-label
Administrationinjection
FDA statustype-2-diabetes
List price$1,069/mo

Weight loss comparison (220 lbs starting weight)

% of body weight lost over 18 months, modeled from phase 3 trial data

Monthly cost by payment channel

ChannelZepboundMounjaroDifference
Covered by insurance ($25–150 copay)$88$88$0 (Mounjaro cheaper)
Manufacturer self-pay (LillyDirect / NovoCare)$349
Telehealth — brand name (Hims, Ro, Found)$499$499$0 (Mounjaro cheaper)
Cash retail (full list price)$1,059$1,069$10 (Zepbound cheaper)

Zepbound pros and cons

Pros
  • Highest efficacy of any FDA-approved GLP-1 (22.5% in SURMOUNT-1)
  • Dual GLP-1/GIP mechanism
  • LillyDirect self-pay vials starting around $349/mo for lower doses
  • FDA-approved for chronic weight management
Cons
  • List price still high ($1,059/mo)
  • Insurance coverage varies more than for Wegovy
  • GI side effects can be more pronounced at higher doses
  • Periodic supply constraints during demand spikes

Mounjaro pros and cons

Pros
  • Identical molecule to Zepbound
  • Easier insurance approval if you have type 2 diabetes
  • Strong cardiovascular and renal data (SURPASS-CVOT, SURMOUNT-MMO)
Cons
  • Off-label for weight loss — most insurers deny
  • Cash-pay typically more expensive than Zepbound LillyDirect option

Common side effects

Zepbound
  • Nausea
  • Diarrhea
  • Constipation
  • Vomiting
  • Decreased appetite
Mounjaro
  • Nausea
  • Diarrhea
  • Constipation
  • Vomiting

Which should you choose: Zepbound or Mounjaro?

Choose Zepbound if: you want maximum weight loss (22.5% vs 20.9%); cash-pay cost matters most to you; you want a drug FDA-approved specifically for weight loss.

Choose Mounjaro if: you have type 2 diabetes (insurance is more likely to cover).

Final decisions should always be made with a licensed prescriber. This is educational content only.

Run your own projection on the full calculator →
Medical disclaimer: This calculator provides estimates only based on phase 3 clinical trial data and publicly listed prices. It is not medical advice. Real-world weight loss varies significantly. Consult a licensed healthcare provider before starting any medication.

More comparisons

💸 Find your cheapest GLP-1 →