IGF-1 LR3
/ Modified IGF-1 analog with N-terminal extension and Arg-for-Glu substitution at position 3; reduced IGFBP affinityALIAS · Long R3 IGF-1 · LR3 IGF-1
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Originally developed for cell-culture applications as a research reagent. No pharmaceutical human development. All in-vivo data is preclinical. Widely sold in the research-chemical market for body-composition purposes with no published human trial support.
IGF-1 LR3 is a modified analog of insulin-like growth factor 1 with a 13-amino-acid N-terminal extension and an Arg-for-Glu substitution at position 3. These modifications reduce affinity for IGF-binding proteins, extending effective half-life at the IGF-1 receptor. Originally developed as a research reagent for cell culture applications.
No pharmaceutical human development program exists. All in-vivo data is preclinical (primarily rodent lean-mass and growth studies). Research-chemical market use is not supported by published human clinical trials.
No human safety data at doses commonly promoted on the research-chemical market. Theoretical oncogenic concern exists because elevated IGF-1 signaling is implicated in several cancer pathways; long-term safety data at research-chemical doses is not available.
Regulatory status
- FDA status:
- Not FDA-approved
Originally a cell-culture reagent, IGF-1 LR3 has migrated to the research-chemical market for body-composition purposes despite no in-vivo human trial supporting those uses. Prolonged IGF-1R signaling is mechanistically distinct from the pulsatile endogenous IGF-1 profile.