Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of IGF-1 LR3 and Ipamorelin — mechanism, side effects, legal status, and pricing.
IGF-1 LR3 is an 83-amino-acid modified IGF-1 analog with a 13-residue N-terminal extension (MFPAMPLSSLFVN) and an Arg-3 substitution. These modifications reduce binding to IGF binding proteins (IGFBPs), extending effective half-life and increasing tissue bioavailability relative to native IGF-1. It is a research/cell-culture reagent and is NOT FDA-approved for any human use. Do not confuse with mecasermin (Increlex), which is recombinant human IGF-1 and IS FDA-approved for severe primary IGF-1 deficiency.
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) originally developed by Novo Nordisk and later advanced by Helsinn/Nycomed. It is a selective ghrelin receptor agonist / growth hormone secretagogue (GHRP). Its defining feature versus older GHRPs (GHRP-2, GHRP-6, hexarelin) is that in preclinical and early clinical studies it raised GH without meaningfully increasing ACTH, cortisol, or prolactin. It is not FDA-approved for any indication; a Phase 2 trial for postoperative ileus failed to meet its primary endpoint and clinical development was discontinued. In the wellness/grey market it is sold as a research chemical and used off-label for anti-aging and body-composition goals despite no clinically validated human dose for those uses.
IGF-1 LR3
Ipamorelin
Category
Legal Status
Mechanism
Half-life
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
IGF-1 LR3
Ipamorelin
COA corpus from Disclosed Labs — independently tested batches only.
IGF-1 LR3
42
COAs
98.7%
Avg purity
9
Labs
Ipamorelin
153
COAs
99.7%
Avg purity
17
Labs
Ipamorelin is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. IGF-1 LR3 remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
Francis et al. (J Mol Endocrinol 1992; PMID 1378742) characterized LR3-IGF-1 as a fusion analog whose enhanced biological potency derives from reduced IGFBP binding; in IGFBP-free cell systems LR3 was actually LESS potent than native IGF-1, underscoring that the 'potency' is really reduced sequestration rather than intrinsically stronger receptor activation. Tomas (Growth Horm IGF Res 2001; PMID 11472075) infused LR(3)IGF-I into food-restricted rats and found it preserved body weight and nitrogen retention but did NOT conserve skeletal muscle protein — which contradicts the common 'potent muscle builder' framing from preclinical literature alone. There are no controlled human trials supporting bodybuilding use. Epidemiologic and mechanistic work reviewed by Grimberg (Cancer Biol Ther 2003; PMID 14688466) links elevated IGF-1 axis activity to breast, prostate, and colorectal cancer risk, so chronic systemic LR3 exposure carries a concrete — not merely theoretical — tumorigenesis concern. IGF-1 and its analogs are banned at all times under the WADA Code.
Key references
The seminal preclinical characterization (Raun et al., 1998, PMID 9849822) established ipamorelin as the first GHRP-receptor agonist with GH-release selectivity comparable to GHRH, without raising ACTH or cortisol even at doses more than 200-fold above the ED50. Pharmacokinetic-pharmacodynamic modeling in healthy male volunteers (Gobburu et al., 1999, PMID 10496658) confirmed a roughly 2-hour half-life and dose-dependent GH response following IV infusion. The most advanced human study is Beck et al. (2014, PMID 25331030), a Phase 2, randomized, double-blind, placebo-controlled trial in 114 patients after bowel resection evaluating IV ipamorelin 0.03 mg/kg twice daily for postoperative ileus; the drug was well tolerated but did not separate from placebo on the primary endpoint (time to tolerance of solid food), and the sponsor (Helsinn/Nycomed) discontinued development. There are no completed registrational trials in adult GH deficiency, frailty, or body-composition indications. Ipamorelin is not FDA-approved for any indication. The 100–300 mcg dose range reflects community/compounding practice and is not clinically validated for anti-aging or body-composition use.
IGF-1 LR3 and Ipamorelin are both in the Performance category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Side Effects
Contraindications
Lab Testing
Key references
Disclosed Labs