Overview
IGF-1 DES (Des(1-3)IGF-1) is a naturally occurring truncated form of insulin-like growth factor-1 in which the first three N-terminal amino acids (Gly-Pro-Glu) have been removed. This structural modification dramatically reduces binding affinity for IGF-binding proteins (IGFBPs), rendering essentially all circulating peptide bioavailable for receptor engagement. First isolated from human brain tissue, it is approximately 10-fold more potent than native IGF-1 in vitro and produces highly localized anabolic effects at the injection site due to its short 20–30 minute half-life.
Mechanism of action
IGF-1 DES activates the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase, with higher affinity than native IGF-1 because the N-terminal tripeptide normally facilitates IGFBP binding. Without IGFBP sequestration, virtually 100% of IGF-1 DES is free to engage IGF-1R. Receptor activation triggers auto-phosphorylation and downstream signaling through two primary cascades: (1) PI3K/Akt/mTOR, driving protein synthesis and inhibiting protein degradation via FoxO transcription factor suppression, and (2) MAPK/ERK, promoting cell proliferation. Uniquely, local injection drives satellite cell activation and myogenic precursor proliferation (hyperplasia — new fiber formation), not just hypertrophy of existing fibers. The very short half-life confines these effects to tissue near the injection site, making it a tool for site-specific muscle remodeling in research contexts.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| localized muscle tissue research (preclinical) | subcutaneous | 20–100 mcg | once daily post-workout | Research protocols typically inject 20–100 mcg bilaterally into target muscle groups immediately post-exercise. Short half-life requires site-specific injection. Cycle 4–6 weeks. |
| localized muscle tissue research (preclinical) | intramuscular | 20–100 mcg | once daily post-workout | Direct intramuscular injection into target tissue is reported to maximize localized IGF-1R activation. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Seminal PubMed research (Ballard et al., 1991) demonstrated 2-3x greater potency of des(1-3)IGF-1 versus IGF-1 in lit/lit growth hormone-deficient mice. Multiple in vitro studies confirm significantly reduced IGFBP-3 binding and enhanced IGF-1R activation kinetics. Animal models demonstrate localized muscle hypertrophy and hyperplasia at injection sites without equivalent systemic effects seen with IGF-1 LR3. No controlled human clinical trials have been published. Current use is confined to research settings. Sports anti-doping bodies (WADA) prohibit IGF-1 DES in competitive athletes.
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with IGF-1 DES for synergistic effects.
Legal status
Not FDA-approved for any indication. Prohibited in sport by WADA. Available from research peptide suppliers in the US for laboratory use. Subject to import restrictions in some jurisdictions. Not a Schedule I–V controlled substance in the US but considered a prescription drug analogue in some countries.
Where to get it
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