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
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 analog of growth hormone-releasing hormone (GHRH) that stimulates the pituitary gland to produce more growth hormone. Available with or without a Drug Affinity Complex (DAC) that extends its half-life.
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 GHRH receptors on the pituitary gland, stimulating pulsatile release of growth hormone. The DAC version binds to albumin in the blood, extending the half-life from minutes to approximately 6-8 days.
- Muscle growth and hypertrophy
- Recovery from injury
- Fat loss
- Anti-aging protocols
- Athletic performance enhancement
- Growth hormone optimization
- Improved sleep quality
- Fat loss
- Muscle recovery
- Anti-aging protocols
- 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
- Water retention
- Tingling or numbness
- Potential cortisol elevation
- Limited long-term safety data
- May affect blood sugar levels
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.
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.