Compare Peptides

Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.

Popular comparisons

IGF-1 LR3

Insulin-like Growth Factor-1 Long R3, Long R3 IGF-1

Unregulated
Growth & Anabolic

Hexarelin

Examorelin, His-D-2-MeTrp-Ala-Trp-D-Phe-Lys-NH2

Category 1
Growth Hormone Secretagogue
Overview

A synthetic analog of insulin-like growth factor-1 (IGF-1) with an extended half-life due to a modified arginine-3 sequence. IGF-1 is naturally produced in the liver in response to growth hormone. The LR3 variant is approximately 3x more potent than native IGF-1 and resists binding to IGF-binding proteins, extending its activity.

A synthetic hexapeptide growth hormone secretagogue and one of the most potent GH-releasing peptides known. Stimulates GH release more strongly than most other GHS peptides, but also has significant effects on cortisol and prolactin.

Mechanism of Action

Binds to IGF-1 receptors throughout the body, stimulating cell growth, proliferation, and differentiation. Promotes protein synthesis, glucose uptake, and fat oxidation. Activates the PI3K/Akt/mTOR pathway — the primary anabolic signaling cascade. Unlike GH secretagogues, IGF-1 LR3 acts directly at the tissue level rather than through the pituitary.

Binds to ghrelin receptors (GHS-R1a) in the pituitary and hypothalamus, triggering strong GH release. Also has direct cardioprotective effects independent of GH, including protection against ischemia-reperfusion injury. Activates the CD36 receptor in cardiac tissue.

Common Uses
  • Muscle growth and hypertrophy
  • Recovery from injury
  • Fat loss
  • Anti-aging protocols
  • Athletic performance enhancement
  • Growth hormone optimization
  • Muscle mass and strength
  • Fat loss
  • Cardiac protection (emerging research)
  • Recovery from injury
Known Risks
  • Hypoglycemia (blood sugar drop) — significant risk, especially post-workout
  • Potential tumor growth promotion (IGF-1 pathway implicated in cancer)
  • Acromegaly-like effects with chronic high-dose use
  • Joint pain
  • Water retention
  • Limited long-term human safety data
  • High abuse potential in athletic contexts
  • Significant cortisol and prolactin elevation (more than Ipamorelin)
  • Water retention
  • Increased appetite
  • Desensitization with prolonged use
  • Limited long-term human safety data
Regulatory Status
Unregulated

Not FDA-approved and not on any compounding list. Available as a research chemical. One of the more potent anabolic peptides — the hypoglycemia risk is real and requires careful dosing. Not affected by the 2026 regulatory changes.

Category 1

Reclassified to Category 1 in February 2026 as part of the HHS announcement restoring compounding access. Not affected by the April 15, 2026 Category 2 removal action. Available through licensed 503A compounding pharmacies with a physician prescription.

This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.