Peptide data sheet
IGF-1 LR3
Performance · Long R3 IGF-1 · IGF-1 Long R3 · LR3 IGF-1
Verdict
unprovenfor muscle and recovery uses in humans, where controlled trials are essentially absent
By MrPepTalks Editorial
Reviewed for scientific accuracy · research information, not medical advice
Last updated Reviewed
Quick answer
IGF-1 LR3 (Long R3 IGF-1) is a synthetic, longer-lasting analog of insulin-like growth factor 1. It is commonly researched for muscle-cell growth and tissue signaling, and people in fitness communities report interest in recovery and lean mass. Controlled human evidence is essentially absent, side effects are not well characterized, it is banned in sport, and it is not FDA-approved for human use.
- Class
- Synthetic long-acting IGF-1 analog (IGF-1 receptor agonist)
- Half-life
- Extended vs native IGF-1; commonly reported around 20-30 hours in lab characterizations
- FDA status
- Not FDA-approved; sold for research/laboratory use only
- WADA banned?
- Yes
Which form actually works?
Injectable (subcutaneous, research)
Unproven
Nearly everything you read about IGF-1 LR3 assumes an injectable research form. There is no controlled human trial evidence behind the muscle and recovery uses people talk about, so treat this as unproven rather than promising.
Oral / topical
Unproven
IGF-1 LR3 is a peptide, so oral routes face the usual digestion problem, and topical claims have essentially no supporting data. Anything marketed this way should be read as unproven.
Third-Party Testing & Certificate of Analysis (COA)
A certificate of analysis (COA) is a lab document that reports what a specific batch of material actually contains. Reputable research suppliers publish one for every batch, tied to a lot number you can match against the vial you received.
- HPLC — purity
- High-performance liquid chromatography reports purity as a percentage: how much of the sample is the intended compound rather than impurities.
- Mass spectrometry (MS) — identity
- Mass spectrometry confirms identity by measuring the sample's molecular mass, so it matches the peptide the label names.
It also matters who ran the test. In-house results come from the seller's own lab; an independent third-party lab has no stake in the result, so its COA generally carries more weight. Look for a named testing laboratory, a batch or lot number, and a test date that lines up with the vial in hand.
New to reading one? This guide walks through a COA line by line: how to read a peptide COA.
Sources
- Tomas FM, Knowles SE, Owens PC, Chandler CS, Francis GL, Read LC, Ballard FJ. Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats. Biochem J. 1992;282(Pt 1):91-97.
- Francis GL, Ross M, Ballard FJ, Milner SJ, Senn C, McNeil KA, Wallace JC, King R, Wells JR. Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I indicate the relative importance of IGF-binding protein and receptor binding for enhanced biological potency. J Mol Endocrinol. 1992;8(3):213-223.
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