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IGF-1 LR3 vs Semax & Selank

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

IGF-1 LR3

IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.

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Semax & Selank

A nootropic combination pairing two Russian-developed peptides for cognitive enhancement. Semax provides stimulating focus and neuroprotection while Selank offers anxiolytic and mood-stabilizing effects, creating a balanced cognitive enhancement stack.

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Side-by-Side Comparison

AspectIGF-1 LR3Semax & Selank
MechanismBinds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours.Semax enhances BDNF expression and modulates dopamine and serotonin systems for improved focus, memory, and neuroprotection. Selank affects BDNF and GABA systems, providing anxiolytic effects and immune modulation. Together they support cognitive function while managing stress and anxiety.
Typical DosageResearch protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles.Semax: 200-600mcg intranasally 2-3 times daily. Selank: 250-500mcg intranasally 2-3 times daily. Can be used together or alternated based on needs.
AdministrationIntramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off.Primarily administered intranasally for rapid brain uptake. N-Acetyl versions (NA-Semax, NA-Selank) offer enhanced stability and potency. Can also be injected subcutaneously.
Side EffectsHypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions.Semax may cause mild irritability or hair shedding. Selank may cause mild fatigue or nasal irritation. Both are generally well-tolerated.
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Key Differences

Unique to IGF-1 LR3:

Unique to Semax & Selank:

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