IGF-1 LR3 · DOSSIER

IGF-1 LR3

Long R3 IGF-1 · Long Arg3 IGF-1 · Peptide · 83 AS
LEGAL DE · NOT APPROVEDEVIDENCE · PRECLINICAL2 STUDIESWADA · S2
FIG.01 — SIGNAL CHAIN
MFPAMPLSSLFVN-[Arg³]-IGF-1 (83 AS) · ~9117.5 Da
02

Mechanism of action

What IGF-1 LR3 does in the body — step by step.

01

IGF-1 LR3 is a synthetically modified variant of human IGF-1.

02

The modification comprises an N-terminal extension of 13 amino acids and the substitution of arginine with glutamic acid at position 3.

03

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.

03

Research status

How far along is the evidence?

PRECLINICALEARLY CLINICAL STUDIESCLINICALLY ESTABLISHED
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.
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.
04

Known risks

Without human data, safety statements are limited. What is known:

01
Hypoglycaemia: pronounced due to long half-life and reduced IGFBP binding
02
No clinical safety data — risk profile in humans unknown
03
Potentially stronger and harder-to-control proliferative effects than native IGF-1
04
Theoretical oncological risk from prolonged IGF-1R activation
05
No regulated manufacturing standards from research-chemical sources
05

Cited studies

Chronological — links lead to the source.

1992
Long R3 IGF-I — an IGF-1 analogue that does not bind IGF-binding proteins and has enhanced metabolic activity in vitro and in vivo
PubMed 1378228 →
2015
Insulin-like growth factor binding proteins: their role in controlling IGF bioavailability and cell signaling
PubMed 25614429 →
06

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.

What is IGF-1 LR3 used for?+

In research, IGF-1 LR3 has primarily been investigated in the context of: Muscle growth. These are research findings (evidence: preclinical), not proven benefits in humans and not a usage recommendation.

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.

Is IGF-1 LR3 FDA-approved / legal in the US?+

No. IGF-1 LR3 is not FDA-approved as a drug in the US; it is mostly sold as a research chemical and not for human consumption.

Is IGF-1 LR3 legal in Canada?+

No. IGF-1 LR3 is not authorized by Health Canada and not intended for human consumption.

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.

What is the dosage of IGF-1 LR3?+

Peptica publishes no dosing. There are no approved dosing guidelines for IGF-1 LR3; figures circulating online stem from animal studies or anecdote, not from validated human protocols. This is not medical advice.

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.

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Dossier

Legal · Structure · Sources.

LEGAL STATUS BY REGION
Germanynot approved

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).

Legal status varies by country and can change. This is not legal advice.

STRUCTURE & MOLECULE
H₂NMFPAMPLSSLFVN-[Arg³]-IGF-1 (83 AS)COOH
83
AMINO ACIDS
~9117.5
MOL. WEIGHT (Da)
Markedly extended
HALF-LIFE
SOURCES & EXTERNAL DATABASES

Methodology: Peptica compiles publicly available studies and regulatory information and assigns each statement an evidence level. Not medical advice. No warranty.

RELATED PEPTIDES & FURTHER READING
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Community notes

Note: These posts are user opinions and not medical advice. Posts containing dosages, therapeutic claims or purchase recommendations are removed. All entries are manually reviewed before publication.
This page is intended solely for factual, scientifically oriented information. No medical advice · no dosage or usage recommendations · no claims of efficacy · no substitute for medical consultation. Peptica sells no substances. Partner links are marked as advertising; Peptica may earn a commission. © 2026 Peptica · Issue 01