Medication Comparison

Zepbound vs Mounjaro

Same active ingredient, different FDA approvals and coverage

Mounjaro

Dual GIP/GLP-1 receptor agonist
Brand Names Mounjaro (tirzepatide)
Manufacturer Eli Lilly
FDA Approved May 2022 for type 2 diabetes
Dosing Weekly injection. 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg.

Zepbound

Dual GIP/GLP-1 receptor agonist
Brand Names Zepbound (tirzepatide)
Manufacturer Eli Lilly
FDA Approved November 2023 for chronic weight management
Dosing Weekly injection. Same doses as Mounjaro: 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg.

How They Work

Mounjaro

Dual GIP/GLP-1 receptor agonist. Same active ingredient as Zepbound.

Zepbound

Identical to Mounjaro (tirzepatide). FDA-approved specifically for weight loss.

Weight Loss Efficacy

~15-21% body weight (off-label for weight loss)

SURPASS trials focused on A1C reduction, with significant weight loss as secondary outcome

~20-22% average body weight in SURMOUNT trials (72 weeks)

SURMOUNT-1 trial: 22.5% weight loss at 15 mg dose vs 3.1% placebo (72 weeks, n=2,539)

Side Effects

Mounjaro

  • Nausea (18%)
  • Diarrhea (17%)
  • Decreased appetite (12%)
  • Vomiting (6%)
  • Constipation (7%)

Zepbound

  • Nausea (33%)
  • Diarrhea (25%)
  • Vomiting (17%)
  • Constipation (20%)
  • Injection site reactions (7%)

Cost Comparison

Mounjaro Zepbound
Without Insurance $1,000-$1,100/month $1,000-$1,100/month
With Insurance $0-$25/month for diabetes with qualifying insurance $0-$550/month depending on plan; coverage expanding in 2026
Compounded Compounded tirzepatide: $250-$550/month Compounded tirzepatide: $250-$550/month

Pros & Cons

Mounjaro

Advantages

  • Strong insurance coverage for type 2 diabetes
  • Same active ingredient as Zepbound
  • Multiple dose options for fine-tuning
  • Well-tolerated GI side effect profile

Considerations

  • Not FDA-approved for weight loss
  • Off-label weight loss use may not be covered
  • Requires diabetes or related diagnosis for insurance coverage
  • Newer drug with limited long-term data (since 2022)

Zepbound

Advantages

  • FDA-approved specifically for weight loss
  • Clinical trials designed for weight management outcomes
  • Identical active ingredient to Mounjaro at same doses
  • Growing insurance coverage for weight loss indication

Considerations

  • Insurance coverage still limited for weight loss
  • Higher out-of-pocket cost if not covered
  • Newer approval (2023) — less prescribing history
  • Side effect rates reported higher in weight loss trials

The Bottom Line

Mounjaro and Zepbound are the same drug (tirzepatide) made by Eli Lilly. If you have type 2 diabetes, Mounjaro offers better insurance coverage. If your primary goal is weight management without diabetes, Zepbound is the appropriate prescription. Your doctor and insurance plan will largely determine which you receive.

Frequently Asked Questions

Yes. Both contain tirzepatide made by Eli Lilly. The difference is FDA labeling: Mounjaro is approved for type 2 diabetes, Zepbound for chronic weight management. Same drug, same doses, different indication.

When the primary goal is weight loss (without type 2 diabetes), prescribing Zepbound aligns with the FDA-approved indication. This can also affect insurance coverage — some plans cover Zepbound for weight loss but not off-label Mounjaro.

The list price is similar ($1,000-$1,100/month). The real cost difference comes down to insurance. Mounjaro is more likely covered under diabetes benefits, while Zepbound coverage depends on whether your plan includes weight loss medications.

Yes, since they're the same drug, switching is seamless. Your doctor can match your current dose exactly. The main reason to switch is usually insurance-related.

Medical Disclaimer: This comparison is for informational purposes only and is not medical advice. All clinical data is sourced from FDA prescribing information and published peer-reviewed trials. Individual results vary. Always consult a qualified healthcare provider before starting, stopping, or switching any medication.