Skip to content
Peptigraph home

IGF-1 LR3 vs Sermorelin: What the Research Shows

IGF-1 LR3 and Sermorelin side by side: what they are, how they are regulated and what is still unknown.

Medically reviewed by Juan Pablo Frías, MD · · DisclosureUpdated
IGF-1 analogNot FDA approved · research chemicalIGF-1 LR3IGF-1 LR3, a long-acting IGF-1 analog with no published human trial; in rats it was 2.5 to 3 times more potent than IGF-I at restoring growth.[16]Growth hormone+230% searchesGHRH analogCompounded by prescriptionSermorelinGHRH analog once FDA-approved as Geref and since discontinued; in an uncontrolled pediatric study mean height velocity rose from 4.1 to 8.0 cm/yr after 6 months.[17]Growth hormoneFlat YoY
Quick verdict

Where the research points

Summary of studies, not a recommendation

Consider IGF-1 LR3 if…

No sourced contrast for this side yet. We add a point here only when it is tied to a study or label.

Consider Sermorelin if…

  • you want human data in growth-hormone-deficient children, though uncontrolled: Mean height velocity rose from 4.1 cm/yr at baseline to 8.0 cm/yr at 6 months and 7.2 cm/yr at 12 months (open-label, no control group).[17]

What they have in common

  • Only animal or lab studies of IGF-1 LR3 were found (e.g. rat): The IGF-I variants were 2.5-3 times more potent than IGF-I at restoring growth in diabetic rats.[16]
  • Sermorelin's only FDA record is Geref, listed with marketing status Discontinued[18]
Sermorelin is not FDA approved. Both are prohibited in tested sport (WADA). Status labels come from public FDA and WADA records; see the sources below.
Side by side

Spec comparison

Showing 11 of 13 fields where the two differ. Category, PCAC vote, Jul 2026 are the same or both unknown.

FieldIGF-1 LR3Sermorelin
ClassIGF-1 analogGHRH analog
Also calledLR3—
FDA statusNot FDA approved · research chemicalCompounded by prescription
WADAProhibited by WADA (S2.3)IGF-1 and its analogues (LR3 is an IGF-1 analogue) are prohibited in S2.3, at all times.Prohibited by WADA (S2.2.4)Sermorelin is named as a GHRH analogue in S2.2.4 (growth hormone releasing factors), prohibited at all times.
Anti-doping detectionNone reportedanti-doping literature, as of 2 Oct 2026
  • A urine assay detects CJC-1295 and other GHRH analogues at very low concentrations.PMID 35298973
  • Labs expect GHRH analogues like CJC-1295 to be hard to find because of tiny urine concentrations; the study reports no detections in routine anti-doping samples.PMID 34665524
Half-life563 min half-life in wound fluid (versus 872 min for IGF-I)wound chamber (rat) (rat) · The American journal of physiology 1999, PMID 10198302No published half-life foundPubMed search, 2 Oct 2026
Evidence strengthHuman observational evidence, 3 of 4Strongest: Growth hormone & IGF research 2010, PMID 20675162Human RCT evidence, 4 of 4Strongest: The Journal of clinical endocrinology and metabolism 1992, PMID 1379256
Human studies we summarised1 human (0 randomized or controlled) of 12 summarised4 human (1 randomized or controlled) of 7 summarised
Typical study doses
Vial sizes sold0.1 mg, 1 mg2 mg, 5 mg, 9 mg, 15 mg
US searches per month22,200 · +230% searches165,000 · Flat YoY

Bracketed values are pending a sourced figure. Legal data reflects the regulatory events in our tracker.

Sources

  1. 1World Anti-Doping Code International Standard Prohibited List 2026World Anti-Doping Agency · 2026wada-ama.orgAccessed 2 Oct 2026
  2. 2Clearance of IGFs and insulin from wounds: effect of IGF-binding protein interactions.The American journal of physiology · 1999PMID 10198302Accessed 2 Oct 2026
  3. 3Detection of His-tagged Long-R³-IGF-I in a black market product.Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society · 2010PMID 20675162Accessed 2 Oct 2026
  4. 4IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep.American journal of physiology. Endocrinology and metabolism · 2025PMID 39679943Accessed 2 Oct 2026
  5. 5Intranasal long R3 insulin-like growth factor-1 treatment promotes amyloid plaque remodeling in cerebral cortex but fails to preserve cognitive function in male 5XFAD mice.Journal of Alzheimer's disease : JAD · 2025PMID 39610283Accessed 2 Oct 2026
  6. 6Insulin-like growth factor-I and analogues increase growth in artificially-reared neonatal pigs.The British journal of nutrition · 2002PMID 12067429Accessed 2 Oct 2026
  7. 7An antibody-free, ultrafiltration-based assay for the detection of growth hormone-releasing hormones in urine at low pg/mL concentrations using nanoLC-HRMS/MS.Journal of pharmaceutical and biomedical analysis · 2022PMID 35298973Accessed 2 Oct 2026
  8. 8Advances in the detection of growth hormone releasing hormone synthetic analogs.Drug testing and analysis · 2021PMID 34665524Accessed 2 Oct 2026
  9. 9Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men.The Journal of clinical endocrinology and metabolism · 1992PMID 1379256Accessed 2 Oct 2026
  10. 10Growth Hormone Secretagogue Treatment in Hypogonadal Men Raises Serum Insulin-Like Growth Factor-1 Levels.American journal of men's health · 2017PMID 28830317Accessed 2 Oct 2026
  11. 11Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men.Metabolism: clinical and experimental · 1997PMID 9005976Accessed 2 Oct 2026
  12. 12PubMed search: (sermorelin[tiab] OR Geref[tiab]) (34 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  13. 13PubMed search: (sermorelin[tiab] OR "GHRH(1-29)"[tiab] OR "GRF(1-29)"[tiab] OR "GHRH 1-29"[tiab]) AND (elderly[tiab] OR aging[tiab] OR "older adults"[tiab] OR adults[tiab]) AND (treatment[tiab] OR therapy[tiab] OR administration[tiab]) (15 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  14. 14PubMed search: (sermorelin[tiab] OR Geref[tiab]) AND (half-life[tiab] OR pharmacokinetic*[tiab]) (2 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  15. 15PubMed search: ("Long R3"[tiab] OR (LR3[tiab] AND (IGF[tiab] OR "IGF-1"[tiab] OR "IGF-I"[tiab] OR "insulin-like growth factor"[tiab]))) AND (sermorelin[tiab] OR Geref[tiab])PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  16. 16Insulin-like growth factor-I and more potent variants restore growth of diabetic rats without inducing all characteristic insulin effects.The Biochemical journal · 1993PMID 7683875Accessed 2 Oct 2026
  17. 17Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study Group.The Journal of clinical endocrinology and metabolism · 1996PMID 8772599Accessed 2 Oct 2026
  18. 18Drugs@FDA (openFDA) search: active ingredient "sermorelin"U.S. Food and Drug Administration · 2026api.fda.govAccessed 2 Oct 2026

Found an error? Report a correction.