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 pegylated form of Mechano Growth Factor, a splice variant of IGF-1 produced in response to mechanical stress on muscle tissue. The PEG (polyethylene glycol) modification extends the half-life from minutes to hours. Studied for muscle repair, hypertrophy, and recovery from injury. One of the 12 peptides removed from Category 2 in April 2026.
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.
MGF is produced when muscle tissue is damaged or mechanically loaded. It activates satellite cells (muscle stem cells) and promotes their proliferation and differentiation into new muscle fibers. The PEG modification prevents rapid degradation, allowing sustained signaling. Works through the IGF-1 receptor but with distinct downstream effects from systemic IGF-1.
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.
- Muscle repair and recovery
- Hypertrophy support
- Injury rehabilitation
- Age-related muscle loss (sarcopenia)
- Athletic recovery protocols
- Muscle growth and hypertrophy
- Recovery from injury
- Fat loss
- Anti-aging protocols
- Athletic performance enhancement
- Injection site pain and swelling
- Hypoglycemia risk
- Potential for uncontrolled cell proliferation
- Limited human safety data
- Banned by WADA in competitive sports
- 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
Removed from Category 2 on April 22, 2026. Scheduled for PCAC Group 2 review (by February 2027). Not FDA-approved for any indication. Previously restricted under Category 2 since September 2023.
PCAC: 2027-02-01
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.
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.