IGF1-LR3 (Long R3 IGF-I) 1 mg/pen (total content)

An IGF-1 variant with an **extended-chain modification** (an additional dipeptide bond and covalent addition spanning the third and third-position residues) designed to replace the multiple-daily-dosing regimen of ordinary IGF-1 with once-daily or alternate-day dosing. The source file marks CAS 143045-27-6 as "reference only"; this check found that the CAS appears in descriptions of a long-acting IGF-1 **trimer/adduct form of about 8,749 Da**, and that different degrees of chain extension and aggregation correspond to different CAS numbers, so **it cannot be used as a universal single CAS**. Documentation should state: "research long-acting variant, CAS reference value (corresponding to a specific trimeric form), subject to supplier identification"

**No approved indication in any jurisdiction.** A research compound, historically studied in growth-hormone-resistant states and in animal growth promotion; human use for muscle gain or fat loss is off-label and prohibited

An extended half-life (several-fold to more than ten-fold that of ordinary IGF-1, depending on chain extension and aggregation state); the mechanism remains IGF1R/IRS/PI3K-AKT and MAPK signalling; equally retains insulin-like glucose-lowering activity and suppression of the GH and gonadal axes. It is one of the most heavily abused "grey" substances in the sports market (a key component of the so-called long-acting GH/IGF market)

Compliant research institutions and approved protocols only; monitor fasting glucose and insulin (hypoglycaemia is the principal risk), IGF-1 levels, thyroid function, hepatic and renal function and lipids; continuous assessment of tumour and bone-density risk during long-term use

**No approved indication.** Use for muscle gain or anti-ageing is prohibited and of uncontrollable risk; can cause severe hypoglycaemia; IGF1R signalling is associated with tumour growth, so it is contraindicated in malignancy; non-medical-market products are **unapproved underground-laboratory products** whose purity, stereochemistry, sterility and endotoxin cannot be relied upon — a serious health and legal risk

Contraindicated in children, adolescents, pregnant and breastfeeding women (no indication); extremely hazardous in diabetes or when using hypoglycaemic drugs, so it should be avoided; high hypoglycaemia risk in the elderly; avoid in hepatic or renal impairment

**Strictly prohibited in competitive sport** (WADA Prohibited List). Off-label aesthetic and muscle-building use is prohibited. Use limited to research institutions holding approval under GLP/GCP conditions. Controlled-substance regulations apply in each jurisdiction; underground-market products must not be accepted

Falls under the WADA Prohibited List S2.2 (growth hormone / IGF-1). Testing uses the GH-200/IGF-1 marker strategy combined with confirmation testing. The long-acting modification **prolongs the detection window** and can complicate interpretation of routine IGF-1 assays, making it one of the most frequently reported sources of anti-doping violations; illicit products frequently also contain GHRPs and GHRHs, further complicating detection and interpretation

Identification (peptide mapping/LC-MS with full molecular weight and chain-extension site confirmation), purity and aggregation analysis (SEC-HPLC/ultrafiltration), potency (bioactivity assay), endotoxin, sterility, lyophilisate appearance and reconstitution characteristics, short-term in-use stability, fill volume, stereochemical confirmation (NMR/CD as required). Labelled content commonly fails to match measured content in illicit products; the COA must be issued by a credible third-party laboratory

**Note**: CAS 143045-27-6 relates only to a specific chain-extension/trimeric form; different extents of chain modification correspond to different CAS numbers, so it cannot be used as a universal single CAS.