Comparison
AOD-9604 vs. IGF-1 LR3
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
221231-10-3
143045-27-6
Molecular weight
1815.09 g/mol
9117.6 g/mol
Half-life
0.4 h
21 h
Sequence
Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-PheMFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSAMechanism of action
AOD-9604
AOD-9604 corresponds to the C-terminal fragment 176-191 of human growth hormone with an additional N-terminal tyrosine. In animal models, lipolytic effects without GH-typical adverse events (insulin resistance, IGF-1 rise) were reported. In humans, these preclinical findings did not translate into clinically relevant weight reduction in the four phase-2 obesity trials. The exact human mechanism of action is unclear; the GH receptor is not classically activated by the fragment.
IGF-1 LR3
IGF-1 LR3 is a recombinantly produced variant of human IGF-1. Two changes define its properties: (1) at position 3, glutamic acid is replaced by arginine; (2) a 13-amino-acid sequence is added at the N-terminus ('Long'). Both modifications drastically reduce affinity for the six IGF-binding proteins (IGFBP-1 to -6) that normally bind native IGF-1 in the blood and regulate its availability at the receptor. As a result, a larger fraction of the molecule is freely available to bind the type-1 IGF receptor (IGF-1R) — the same receptor as native IGF-1. In preclinical models and cell culture, LR3 IGF-1 therefore acts as a more potent agonist than unmodified IGF-1. The downstream signalling pathway (PI3K/Akt and MAPK) is identical to that of IGF-1; the modification changes bioavailability, not the receptor target.
Evidence base
Highest evidence
Human RCT
Animal model
Studies
3
4
of which in humans
2
0
Effects recorded
3
4
Open conflicts
1
1
Documented adverse events
1
1
Legal status
Full entries
Frequently asked questions
- What is the difference between AOD-9604 and IGF-1 LR3?
- AOD-9604 is classified as "Growth", while IGF-1 LR3 is classified as "Growth". AOD-9604: Synthetic 16-amino-acid peptide corresponding to the C-terminal fragment of human growth hormone (hGH 176-191). Originally developed by Metabolic Pharmaceuticals as an oral obesity therapy; all phase-2 trials missed the primary endpoint. No marketing approval. The Australian TGA Schedule 4 classification is often misunderstood. IGF-1 LR3: Synthetic analogue of insulin-like growth factor 1 (IGF-1) carrying an arginine substitution at position 3 and a 13-amino-acid N-terminal extension. These modifications lower binding to IGF-binding proteins and extend its duration of action relative to native IGF-1. LR3 IGF-1 is primarily an established cell-culture reagent (serum-free media, bioprocessing); it is NOT an approved human medicine. Use in the bodybuilding grey market is described; as an IGF-1 analogue, LR3 IGF-1 falls under the WADA anti-doping prohibition. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, AOD-9604 or IGF-1 LR3?
- The highest available evidence level is "Human RCT" for AOD-9604 and "Animal model" for IGF-1 LR3. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of AOD-9604 and IGF-1 LR3 in Germany and the United States?
- Germany: AOD-9604 — Unapproved, IGF-1 LR3 — Unapproved. United States: AOD-9604 — Unapproved, IGF-1 LR3 — Unapproved. These are factual summaries with source and review date on the individual pages.