Is IGF-1 LR3 banned in sport?

Yes. All forms of IGF-1 are prohibited by WADA under S2 (Peptide Hormones, Growth Factors). Banned at all times.

Can IGF-1 LR3 cause cancer?

Elevated IGF-1 levels are associated with increased cancer risk in epidemiological studies. While LR3 has not been directly linked to cancer in research, it promotes cell proliferation which is a theoretical concern. Individuals with any cancer history should avoid it.

Growth Hormone

IGF-1 LR3

Long Arginine 3-IGF-1

Three times more potent than native IGF-1

IGF-1 LR3 is a modified version of insulin-like growth factor 1 with enhanced potency and longer half-life. Used in muscle-building and anti-aging research.

Admin routes

Subcutaneous, Intramuscular

Popularity

Medium

Side effects

Monitor closely

Vendors

1 rated

Key benefits

1Three times more potent than native IGF-1

2Extended half-life of 20–30 hours

3Promotes muscle hypertrophy and recovery

4Supports bone density maintenance

5Enhanced protein synthesis

6Anti-aging applications under investigation

What to expect

Week 1–2

Enhanced muscle pump during exercise; improved recovery

Week 2–4

Increased muscle fullness and vascularity

Week 4–6

Measurable strength and lean mass gains

Week 6–8

Full protocol benefits; cycle off to prevent desensitisation

Based on community reports and published research. Individual results vary significantly.

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Vendor ratings are based on community feedback and are not endorsements. Always verify third-party certificates of analysis (CoA) and check your local regulations before purchasing.

Dosing protocols

Muscle growth

Dose

20–50 mcg

Frequency

Once daily

Duration

4–8 weeks

Recovery

Dose

50–100 mcg

Frequency

Once daily

Duration

4–6 weeks

Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.

Research status|Extensive preclinical data - used in research since the 1990s

Overview

IGF-1 LR3 is a synthetic analog of insulin-like growth factor 1 (IGF-1) with an arginine substitution at position 3 and a 13-amino-acid extension at the N-terminus. These modifications reduce binding to IGF binding proteins, resulting in approximately three times greater potency than native IGF-1 and a half-life of 20–30 hours compared to minutes for natural IGF-1.

How it works

Activates IGF-1 receptors through two primary pathways: the PI3K-AKT pathway (promoting glucose uptake, protein synthesis, and muscle growth) and the RAS-RAF-MAPK pathway (stimulating cell proliferation and tissue regeneration). Its structural modifications make it more bioavailable and longer-lasting in circulation than native IGF-1.

Side effects

Injection site reactions

mildCommon

Headache

mildUncommon

Hypoglycaemia if dosed with insulin

seriousRare

Theoretical tumour growth concern

seriousRare

Research history

1987

IGF-1 first produced by recombinant DNA technology

1992

LR3 variant developed with reduced IGFBP binding

2000s

Widely adopted in bodybuilding community

2010s

WADA intensifies testing for IGF-1 variants

2020s

Research focus shifts to anti-aging and recovery applications

IGF-1 LR3 vs native IGF-1

Native IGF-1 has a half-life of only 12–15 minutes in circulation because 95% is bound to IGF binding proteins (IGFBPs). LR3's structural modifications dramatically reduce IGFBP binding, meaning more free IGF-1 is available to activate receptors. This makes it far more potent per microgram but also requires careful dosing - the extended activity window means effects (including side effects) last longer.

Reconstitution and storage

IGF-1 LR3 typically comes in 1 mg vials. Reconstitute with 1 mL of bacteriostatic water for 1000 mcg/mL. At 50 mcg per dose, this gives 20 doses per vial. Use a 100-unit insulin syringe - 50 mcg = 5 units. Store reconstituted at 2–8°C, use within 3 weeks.

Recommended products

Hand-picked for this compound. Ships via Amazon 🇺🇸

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Core Supplies

Bacteriostatic Water 30mL

Sterile bacteriostatic water for peptide reconstitution. Contains 0.9% benzyl alcohol to inhibit bacterial growth.

❄️

Storage & Transport

Portable Insulin Cooler Fridge

Portable peptide fridge with precise 2-8C cooling. Battery powered, travel-ready. Designed for insulin/peptide storage.

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References

[1]Francis GL, et al. 'Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I.' Journal of Molecular Endocrinology, 1992.
[2]Tomas FM, et al. 'Superior potency of infused IGF-I analogues which bind poorly to IGF-binding proteins.' American Journal of Physiology, 1993.

Frequently asked questions

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Community experiences

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Supplies

Syringes, bac water, storage

Guides

How-to guides

Storage, reconstitution, and travel

Disclaimer: This guide is for educational and informational purposes only. It is not medical advice. The dosing protocols listed are sourced from published research and community reports and do not constitute a recommendation. Always consult a qualified healthcare professional before using any peptide. Check your local regulations regarding peptide purchase and use.