✓ Independent editorial reviews of U.S. telehealth programs · Prices and dates shown on each page · Educational only — not medical advice
Growth Hormone · Peptide Reference

IGF-1 LR3

Released: Last reviewed:

Modified IGF-1 with a 13-aa N-terminal extension and Arg3 substitution that prolongs half-life (~20 hours vs 10 minutes for native IGF-1) by reducing IGF-binding protein affinity. Used for lean mass support and recovery.

Growth Hormone Evidence grade: C Not FDA-approved
Researched By
Dr. Parmis
Medical Researcher · Western University of Health Sciences
Medically Reviewed By
Dr. Jonathan Snipes, MD · Kim Callender, NP (FNP-BC)
Last medically reviewed: October 15, 2026 · This page is informational and does not constitute medical advice.

Key facts

Class
Modified insulin-like growth factor
Half-life
~20 hours (long-acting analog)
Pharmacy pathway
See the dated FDA status notice above
Sports-ban status
WADA prohibited (S2)
Key concern
Hypoglycemia risk; insulin-like action
Common dose
20-40 mcg SC daily
Evidence grade
C (animal studies; bodybuilding-community use)
FDA status
Not FDA-approved

Mechanism of action

Modified IGF-1 with a 13-aa N-terminal extension and Arg3 substitution that prolongs half-life (~20 hours vs 10 minutes for native IGF-1) by reducing IGF-binding protein affinity. Used for lean mass support and recovery.

Standard dosing

Typical clinical use: 20-40 mcg SC daily. Dosing varies by indication and provider protocol; this is reference-only and not a prescribing recommendation. IGF-1 LR3 requires a prescription from a licensed clinician.

Regulatory status & pharmacy pathway

Not FDA-approved. FDA limits which peptides a pharmacy may compound; check this page’s dated FDA status notice before assuming a peptide is legally available. Ask which licensed pharmacy fills the prescription and check that pharmacy’s license with your state board of pharmacy.

U.S. telehealth providers prescribing IGF-1 LR3

The most commonly cited U.S. telehealth providers for IGF-1 LR3 are Defy Medical, Marek Health, Hone Health, Maximus, and PeterMD —, whose offerings for this peptide we have not verified (see the FDA status notice above). See the full provider directory for complete profiles.

Trade-offs to know

IGF-1 LR3 carries the trade-offs common to all compounded peptide therapeutics: not FDA-approved, cash-pay only, no in-network insurance coverage, and pharmacy-quality variation between providers. Choose a prescriber that names its pharmacy, explains its follow-up schedule and states the regulatory status of what it prescribes.

Related peptides in the growth hormone category

Editorial team

Researched by Dr. Parmis (Medical Researcher, Western University of Health Sciences); medically reviewed by Dr. Jonathan Snipes, MD and Kim Callender, NP (FNP-BC).

References

  1. Frystyk J. Free insulin-like growth factors -- measurements and relationships to growth hormone secretion and glucose homeostasis. Growth Horm IGF Res. 2004;14(5):337-375. PMID: 15336229
  2. Tomas FM, Knowles SE, Owens PC, et al. Increased weight gain, nitrogen retention and muscle protein synthesis following treatment of diabetic rats with insulin-like growth factor (IGF)-I and Long-R3-IGF-I. Biochem J. 1991;276(Pt 2):547-554. PMID: 2049082

Sources are peer-reviewed where available. PubMed (PMID) links resolve to NCBI's PubMed database. FDA links resolve to the U.S. Food and Drug Administration. Citations were last verified 2026-05-11.