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IGF-1 LR3

high risk

Also: Long R3 IGF-1 · Insulin-like growth factor 1 LR3

Preliminary Research Only

IGF-1 LR3 is a recombinant analog of IGF-1 with an N-terminal extension (13 amino acids) and Arg substitution that reduces IGF binding protein affinity, extending half-life from ~10 min to ~20 hours. Potently anabolic in animal models. Human data limited; WADA-prohibited.

Molecular Weight
9117.5 Da
Formula
C400H625N111O115S9
Common Dosing
20–50 mcg/day SC post-workout; cycles of 4–6 weeks
Category
research
Last Reviewed
2025-01-15

Reported Benefits

Anabolic / muscle growth

Preliminary 16 studies

Consistent anabolic effects in animal models. Human performance data largely anecdotal/extrapolated.

Mechanism of Action

IGF-1 receptor agonist with reduced binding protein affinity; activates PI3K-Akt-mTOR and MAPK pathways driving protein synthesis, cell proliferation, and satellite cell activation.

Hypoglycemia Risk

IGF-1 LR3 has meaningful insulin-like activity. Co-administration with insulin can cause life-threatening hypoglycemia. This is not a theoretical risk — documented severe hypoglycemia cases exist in the performance enhancement community.

Oncogenic Concern

IGF-1 receptor signaling is a primary driver of proliferation in multiple cancers (breast, prostate, colorectal). Chronic IGF-1R upregulation in individuals with undiagnosed malignancies is a serious concern.

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Nava Health

Regulatory Status

Research Only

Safety Profile

Side Effects

  • •Hypoglycemia
  • •Jaw/facial bone growth
  • •Soft tissue swelling
  • •Potential oncogenic risk (IGF-1R promotes tumor growth)
  • •WADA-prohibited

Contraindications

  • •Active malignancy
  • •Cancer history
  • •Insulin-dependent diabetes
  • •Acromegaly

Drug Interactions

  • •Insulin (severe hypoglycemia risk)
  • •Anabolic steroids

Primary Uses

Muscle growthTissue repairAnabolicRecovery

Related Peptides

IGF-1 DESPEGylated MGFTB-500BPC-157

Used For

›Tissue Repair & Recovery

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Disclaimer: This information is for educational and research purposes only. Not medical advice. Consult a qualified healthcare provider before using any compound.