Structure · schematic
Peptide chain of 83 amino acids · IGF / Insulinanalog
Sequence
MFPAMPLSSLFVN-[Arg³]-IGF-1 (83 AS)
Schematic representation of the amino acid chain — not a chemical structural formula. Each node represents one amino acid (shown truncated).
Research areas*
* Contexts in which the peptide has been scientifically studied — not assured or recommended effects.
Mechanism of action
- IGF-1 LR3 is a synthetically modified variant of human IGF-1.
- The modification comprises an N-terminal extension of 13 amino acids and the substitution of arginine with glutamic acid at position 3.
- These structural changes substantially reduce binding affinity to IGF-binding proteins (IGFBPs), increasing bioavailability and extending the biological half-life compared with native IGF-1 (about 12–15 minutes) to an estimated 20 hours.
- The mechanism of action at the IGF-1 receptor is analogous to native IGF-1: activation of the PI3K/Akt/mTOR and Ras/MAPK pathways.
Research status
- IGF-1 LR3 has been used primarily as a research tool in cell culture and animal experiments, where its prolonged duration of action compared with native IGF-1 makes it a practical study instrument.
- Controlled human clinical studies do not exist; IGF-1 LR3 is sold commercially for laboratory purposes only.
- All data on effects on muscle hypertrophy or tissue regeneration in humans come from anecdotal reports — no peer-reviewed evidence.
Evidence level
Cited studies
Known risks
- 01Hypoglycaemia: pronounced due to long half-life and reduced IGFBP binding
- 02No clinical safety data — risk profile in humans unknown
- 03Potentially stronger and harder-to-control proliferative effects than native IGF-1
- 04Theoretical oncological risk from prolonged IGF-1R activation
- 05No regulated manufacturing standards from research-chemical sources
Frequently asked questions
What is IGF-1 LR3?
IGF-1 LR3 is a synthetically modified variant of human IGF-1.
What type of peptide is IGF-1 LR3?
IGF-1 LR3 belongs to the IGF / insulin analog class.
Is IGF-1 LR3 legal in Germany?
IGF-1 LR3 is not approved as a medicine in Germany. Obtaining it outside clinical studies is legally problematic.
Where can I buy IGF-1 LR3?
Peptica sells nothing and names no sources. IGF-1 LR3 is "not approved" in Germany; obtaining unapproved substances outside clinical studies is illegal and carries quality and safety risks.
Is IGF-1 LR3 banned in sport (WADA)?
Yes. IGF-1 LR3 is on the WADA Prohibited List and is therefore banned in competitive sport.
What are the known risks of IGF-1 LR3?
Documented risks include: Hypoglycaemia: pronounced due to long half-life and reduced IGFBP binding; No clinical safety data — risk profile in humans unknown. This is not a complete safety assessment and not medical advice — see the risks section for the full list.
How well researched is IGF-1 LR3?
The evidence is classified as “preclinical”. 2 studies are cited on this page.
What is the molecular weight of IGF-1 LR3?
IGF-1 LR3 has a molar mass of about 9117.5 Da.
Which peptides are related to IGF-1 LR3?
Closely related entries: CJC-1295, IGF-1. A direct side-by-side comparison is available via the compare function.
Related entries
Legal status
Germany
not approvedAustria
not approvedSwitzerland
not approvedEU
not approvedUSA
not approvedCanada
not approvedLegal status varies by country and can change. This is not legal advice.
Sources & methodology
- 2 peer-reviewed studies cited, linked to PubMed where available.
- Molecular data verified against PubChem and primary literature.
- Editorial standard: no dosage guidance, no sources, evidence level stated explicitly.
Last editorially reviewed: 28 May 2026
Legal assessment
IGF-1 LR3 is not an approved medicine in the EU. As a structural IGF-1 analog, it falls under the WADA Prohibited List (S2). Import or possession for purposes other than scientific ones is not legally permitted and may fall under the German Medicines Act (AMG).
Important notice
This site is intended solely for factual, scientifically oriented information about peptides. It does not constitute medical advice, does not replace a consultation with a doctor and contains no recommendations for use in humans.
This site does not sell any substances and names no sources for unapproved substances. For medical questions, please consult qualified medical professionals.
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