Retatrutide vs Tirzepatide

A comprehensive, data-driven comparison of Retatrutide (LY3437943) and Tirzepatide (Mounjaro). Compare efficacy, side effects, costs, FDA approval status, and clinical evidence to make an informed decision.

Obesity and weight management
Evidence
High
Avg. Weight Loss28.7%
Monthly Cost$1,200 - $1,500/mo
DosingWeekly
ManufacturerEli Lilly
Tirzepatide
FDA Approved
Type 2 diabetes and chronic weight management
Evidence
High
Avg. Weight Loss22.5%
Monthly Cost$1,100 - $1,500/mo
DosingWeekly
ManufacturerEli Lilly

Side-by-Side Comparison

PropertyRetatrutide
LY3437943
Tirzepatide
Mounjaro, Zepbound
FDA Status
Phase 3
FDA Approved
Category
Weight Loss
Weight Loss
Primary Use
Obesity and weight management
Type 2 diabetes and chronic weight management
Weight Loss %
28.7%
22.5%
Monthly Cost
$1,200 - $1,500/mo
$1,100 - $1,500/mo
Administration
Subcutaneous injection
Subcutaneous injection
Typical Dose
12mg weekly (dose escalated from 2mg)
15mg weekly (max dose)
Frequency
Weekly
Weekly
Mechanism

Triple agonist targeting GIP, GLP-1, and glucagon receptors to enhance insulin secretion, reduce appetite, and increase energy expenditure

Dual GIP/GLP-1 receptor agonist that enhances insulin secretion, reduces glucagon, slows gastric emptying, and decreases appetite

Common Side Effects
  • Nausea
  • Diarrhea
  • Vomiting
  • Constipation
  • +2 more
  • Nausea
  • Diarrhea
  • Decreased appetite
  • Vomiting
  • +3 more
Serious Side Effects
  • Pancreatitis
  • Gallbladder disease
  • Severe gastrointestinal reactions
  • Hypoglycemia (if combined with insulin)
  • Pancreatitis
  • Hypoglycemia
  • Acute gallbladder disease
  • Hypersensitivity reactions
  • +1 more
Evidence Quality
High
High
Clinical Trial Phase
Phase 3
Approved

Key Differences

  • 1Tirzepatide is FDA-approved, while Retatrutide is currently phase 3.
  • 2Retatrutide showed 28.7% average weight loss in trials compared to 22.5% for Tirzepatide.
  • 3Tirzepatide is generally more affordable ($1,100 - $1,500/mo) compared to Retatrutide ($1,200 - $1,500/mo).

Which Is Better For...

TI

Tirzepatide

Those seeking an FDA-approved treatment with established safety data

RE

Retatrutide

Maximum weight loss efficacy based on clinical trial data

TI

Tirzepatide

More budget-friendly option with lower monthly costs

RE

Retatrutide

Fewer commonly reported side effects

Cost Comparison

PeptideMonthly Cost RangeFDA StatusManufacturer
Retatrutide$1,200 - $1,500/mo
Phase 3
Eli Lilly
Tirzepatide$1,100 - $1,500/mo
FDA Approved
Eli Lilly

Prices are estimated monthly costs and may vary based on pharmacy, insurance coverage, and manufacturer assistance programs. Costs for non-FDA-approved peptides reflect research compound pricing.

Frequently Asked Questions

What is the main difference between Retatrutide and Tirzepatide?

Retatrutide works via Triple agonist targeting GIP, GLP-1, and glucagon receptors to enhance insulin secretion,. Tirzepatide works via Dual GIP/GLP-1 receptor agonist that enhances insulin secretion, reduces glucagon, slows gastric. They differ in FDA approval status, efficacy data, and cost.

Which is more effective for weight loss, Retatrutide or Tirzepatide?

In clinical trials, Retatrutide showed greater average weight loss (28.7%) compared to Tirzepatide (22.5%). Individual results may vary.

How much does Retatrutide cost compared to Tirzepatide?

Retatrutide typically costs $1,200 - $1,500/mo, while Tirzepatide costs $1,100 - $1,500/mo. Prices may vary by pharmacy, insurance coverage, and manufacturer programs.

Are Retatrutide and Tirzepatide FDA approved?

Retatrutide is not FDA-approved (Phase 3). Tirzepatide is FDA-approved. FDA approval indicates the treatment has met rigorous safety and efficacy standards.

What are the side effects of Retatrutide vs Tirzepatide?

Common side effects of Retatrutide include Nausea, Diarrhea, Vomiting. Common side effects of Tirzepatide include Nausea, Diarrhea, Decreased appetite. Always consult a healthcare provider about potential side effects.

Can I switch from Retatrutide to Tirzepatide?

Switching between peptide therapies should only be done under the guidance of a qualified healthcare provider. They can evaluate your medical history, current response, and determine the safest transition protocol.

Learn More

Retatrutide Full Profile
Obesity and weight management

Retatrutide is a novel triple-receptor agonist developed by Eli Lilly currently in Phase 3 clinical trials. It has demonstrated unprecedented weight loss results, with patients losing an average of 28...

View Full Retatrutide Guide
Tirzepatide Full Profile
Type 2 diabetes and chronic weight management

Tirzepatide is a dual-action peptide approved by the FDA as Mounjaro for type 2 diabetes and Zepbound for weight management. It is the first medication to target both GIP and GLP-1 receptors simultane...

View Full Tirzepatide Guide

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Medical Disclaimer

The information provided on this page is for educational and informational purposes only and does not constitute medical advice. This comparison between Retatrutide and Tirzepatide should not be used as a substitute for professional medical guidance. Always consult a qualified healthcare provider before starting, stopping, or modifying any peptide therapy. Clinical data cited may be from ongoing trials and is subject to change. Individual results may vary significantly. PeptideVS does not endorse, recommend, or promote the use of any specific peptide for medical treatment.