Retatrutide vs Ipamorelin

A comprehensive, data-driven comparison of Retatrutide (LY3437943) and Ipamorelin (NNC 26-0161). Compare efficacy, side effects, costs, FDA approval status, and clinical evidence to make an informed decision.

Retatrutide
Phase 3 (NDA expected late 2026)
Obesity and weight management
Evidence
High
Avg. Weight Loss28.7%
Monthly Cost$1,200 - $1,500/mo
DosingWeekly
ManufacturerEli Lilly
Ipamorelin
Category 2 (pending reclassification)
Growth hormone optimization
Evidence
Emerging
Monthly Cost$35 - $70/mo
DosingDaily

Side-by-Side Comparison

PropertyRetatrutide
LY3437943
Ipamorelin
NNC 26-0161
FDA Status
Phase 3 (NDA expected late 2026)
Category 2 (pending reclassification)
Category
Weight Loss
Growth Hormone
Primary Use
Obesity and weight management
Growth hormone optimization
Weight Loss %
28.7%
N/A
Monthly Cost
$1,200 - $1,500/mo
$35 - $70/mo
Administration
Subcutaneous injection
Subcutaneous injection
Typical Dose
12mg weekly (dose escalated from 2mg)
200-300mcg 2-3x daily
Frequency
Weekly
Daily
Mechanism

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

Selective growth hormone secretagogue that binds to ghrelin receptors to stimulate GH release without affecting cortisol or prolactin

Common Side Effects
  • Nausea
  • Diarrhea
  • Vomiting
  • Constipation
  • +3 more
  • Injection site reactions
  • Increased hunger
  • Headache
  • Mild water retention
Serious Side Effects
  • Pancreatitis
  • Gallbladder disease
  • Severe gastrointestinal reactions
  • Hypoglycemia (if combined with insulin)
  • Potential insulin resistance
  • Unknown long-term effects
Evidence Quality
High
Emerging
Clinical Trial Phase
Phase 3
N/A

Key Differences

  • 1Retatrutide has clinical weight loss data (28.7%), while Ipamorelin is not primarily indicated for weight loss.
  • 2Ipamorelin is generally more affordable ($35 - $70/mo) compared to Retatrutide ($1,200 - $1,500/mo).
  • 3Retatrutide is dosed weekly, while Ipamorelin is daily.
  • 4Retatrutide has high-quality evidence, while Ipamorelin has emerging-quality evidence.
  • 5They belong to different categories: Retatrutide (Weight Loss) vs Ipamorelin (Growth Hormone).

Which Is Better For...

IP

Ipamorelin

More budget-friendly option with lower monthly costs

RE

Retatrutide

More convenient dosing schedule (weekly)

IP

Ipamorelin

Fewer commonly reported side effects

RE

Retatrutide

Stronger clinical evidence base to support its use

Cost Comparison

PeptideMonthly Cost RangeFDA StatusManufacturer
Retatrutide$1,200 - $1,500/mo
Phase 3 (NDA expected late 2026)
Eli Lilly
Ipamorelin$35 - $70/mo
Category 2 (pending reclassification)
Various research labs

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 Ipamorelin?

Retatrutide works via Triple agonist targeting GIP, GLP-1, and glucagon receptors to enhance insulin secretion,. Ipamorelin works via Selective growth hormone secretagogue that binds to ghrelin receptors to stimulate GH. They differ in FDA approval status, efficacy data, and cost.

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

Retatrutide has demonstrated 28.7% average weight loss in clinical trials. Ipamorelin is not primarily used for weight loss.

How much does Retatrutide cost compared to Ipamorelin?

Retatrutide typically costs $1,200 - $1,500/mo, while Ipamorelin costs $35 - $70/mo. Prices may vary by pharmacy, insurance coverage, and manufacturer programs.

Are Retatrutide and Ipamorelin FDA approved?

Retatrutide is not FDA-approved (Phase 3 (NDA expected late 2026)). Ipamorelin is not FDA-approved (Category 2 (pending reclassification)). FDA approval indicates the treatment has met rigorous safety and efficacy standards.

What are the side effects of Retatrutide vs Ipamorelin?

Common side effects of Retatrutide include Nausea, Diarrhea, Vomiting. Common side effects of Ipamorelin include Injection site reactions, Increased hunger, Headache. Always consult a healthcare provider about potential side effects.

Can I switch from Retatrutide to Ipamorelin?

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
Ipamorelin Full Profile
Growth hormone optimization

Ipamorelin is a pentapeptide that selectively stimulates growth hormone release by mimicking ghrelin, the hunger hormone. Unlike many other GH secretagogues, ipamorelin does not significantly increase...

View Full Ipamorelin 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 Ipamorelin 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.