Long R3 IGF-1 · IGF-1 Long Arg3
Long-acting IGF-1 — muscle growth and satellite cell activation.
FDA
Research Only
WADA
Banned
HALF-LIFE
~20–30 hours
ROUTE
SubQ or IM injection
SCHEDULE
Daily
In Plain English
Long-acting IGF-1 — muscle growth and satellite cell activation.
Status & Legality
What do these mean?Muscle growth
Satellite cell activation
IGF-1 receptor stimulation
Recovery
IGF-1 LR3 is a recombinant analog of IGF-1 with an arginine substitution at position 3 and an N-terminal 13-amino acid extension, giving it a 20–30× longer half-life than native IGF-1. It binds IGF-1 receptors to drive muscle protein synthesis, satellite cell activation, and hyperplasia (new muscle cell formation).
Hypoglycemia (must eat with it)
Headache
Joint pain
Potential tumor promotion at high doses
Water retention
Facial changes with long-term high doses
Not eating immediately after injection — hypoglycemia is the most common and dangerous side effect; have carbohydrates ready
Using for more than 4–6 weeks without a break — IGF-1 receptor desensitization occurs rapidly with extended use
Injecting on non-training days without targeting recently worked muscles — the anabolic effect is highest in muscles that have been recently loaded
Insulin — significant hypoglycemia risk when combined; avoid unless medically supervised
Growth hormone — additive anabolic and IGF-1 receptor effects; monitor for acromegalic signs during extended combined use
Thyroid medications — thyroid status affects IGF-1 receptor sensitivity; optimize thyroid before starting
IGF-1 LR3 directly drives muscle protein synthesis and satellite cell activation in a way GH secretagogues alone cannot match. Inject post-workout, eat carbohydrates immediately after, and never extend cycles past 6 weeks. The 4–6 week on, 4 week off rhythm prevents receptor desensitization and keeps the anabolic response sharp.
CJC-1295 (NO DAC)
Short-acting GHRH analog — clean GH pulses.
TB-500
Systemic recovery — muscles, blood vessels, inflammation.
IGF-1 DES
Short-acting IGF-1 — localized muscle hypertrophy.
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Stats
Sources & Studies
Fryburg DA. et al., J Clin Invest, 1995