§ Research summary · Growth hormone

IGF-1 LR3 1 mg

Also known as · Long R3 IGF-1 · Long Arg3 IGF-1

Growth hormone·1 min read·reviewed 2026-05-07

Long R3 IGF-1 — an engineered IGF-1 analogue with reduced affinity for IGF-binding proteins and extended plasma half-life. Widely used research reagent.

Chemistry quick-facts

CAS
946870-92-4
Formula
C400H625N111O115S9
MW
9111.28 Da
Length
83 aa
Status
Research reagent. Extensively used in cell-culture and in vivo research. No clinical approval.
Purity (HPLC)
≥ 98.0%

Mechanism of action

IGF-1R-mediated signalling → PI3K/Akt and MAPK pathways. Reduced IGFBP binding increases free-IGF availability in target tissues.

Research context

IGF-1 LR3 is a modified form of insulin-like growth factor 1 with an Arg3 substitution that reduces binding to IGF-binding proteins, and an N-terminal 13-residue extension derived from porcine GH. It is among the most commonly used IGF-1 analogues in muscle-biology and cell-culture research.

Published studies

A non-exhaustive list of peer-reviewed studies referenced when curating this entry. Click through to the primary source for the full text.

  1. Francis GL, Upton FM, Ballard FJ, et al. (1988). Insulin-like growth factors 1 and 2 in bovine colostrum — Long R3 IGF-1 characterization. Biochemical Journal.

Reconstitution

Solvent
Dilute acetic acid (0.1 N) or bacteriostatic water (depending on research context)
Typical volume
1 mL
  • · IGF-1 analogues are sensitive to pH — dilute acetic acid is the reference solvent for research.
  • · Bac water is suitable for short-term reconstitution and most preclinical protocols.

Storage

Lyophilised
−20 °C, desiccated, protected from light. Stable at 15–25 °C for up to 30 days in transit.
Reconstituted
2–8 °C, original vial, consumed within 4 weeks.
Shelf life — sealed
24 months from date of manufacture when stored lyophilised at −20 °C.

FAQ

Why "LR3" in the name?+

Long Arg-3. "Long" refers to the 13-residue N-terminal extension; "Arg-3" is the amino-acid substitution at position 3 that reduces binding-protein affinity.

Research-use disclaimer

This page summarises the research literature on IGF-1 LR3 1 mg for in vitro laboratory investigation only. It is not medical advice, not a treatment recommendation, and not a substitute for a qualified physician. Material is sold for analytical chemistry and cell-culture research, not for human or veterinary administration.

View IGF-1 LR3 1 mg in the catalogue →
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