Research on the N-terminal region of IGF-1 established a key functional role for the first amino acids: the truncated derivative des(1-3)IGF-1 binds IGF-binding proteins far less avidly, increasing receptor availability and potency in cell assays.
IGF-1 DES
Truncated IGF-1 variant for localized muscle growth

WADA PROHIBITED - Not permitted in competitive sports
Overview
Last reviewed: 2026-08-18
Identity & Aliases
Also known as
Full composition (formula, molecular weight, sequence) in Quick Facts →
Research Areas
Available Evidence
No human clinical trials of IGF-1 DES were identified; it is not an approved medicine.
Published animal efficacy studies specifically on des(1-3)IGF-1 were not identified in this review; available evidence is primarily from cell-culture systems.
Cell-based studies established that removing the N-terminal tripeptide markedly reduces IGF-1's affinity for IGF-binding proteins, leaving more free ligand available to the IGF-1 receptor and making the peptide more potent in proliferation assays; des(1-3)IGF-I was also studied in cultured porcine embryonic muscle cells.
Claims of superior muscle-building potency and a very short half-life circulate widely in the peptide community but lack published human pharmacokinetic or clinical data.
Key Studies & Findings
In cultured porcine embryonic muscle cells, IGF-I and des(1-3)IGF-I differentially regulated IGF-binding protein-3, illustrating the truncated peptide's altered binding-protein interactions in muscle-relevant cells.
Benefits & Effects
Side Effects & Safety
Limitations & Open Questions
Pharmacology
Reported Research Dosing
Reported values from research literature and community protocols. Educational reference only — not a dosing recommendation or medical advice.
low microgram ranges
Frequently Asked Questions
What makes IGF-1 DES different from regular IGF-1?
It lacks the first three N-terminal amino acids, which in cell studies greatly reduces its binding to IGF-binding proteins, increasing free ligand for the IGF-1 receptor.
Is IGF-1 DES approved for human use?
No. It is an unapproved research peptide with no human clinical trials.
Does IGF-1 DES have a short half-life?
Short half-life claims circulate widely but were not confirmed in published human pharmacokinetic studies found in this review.
Research Citations
Guan J, Williams CE, Skinner SJ, Mallard EC, Gluckman PD (1996)
Kaplan-Lefko PJ, Sutherland BW, Evangelou AI, Hadsell DL, Barrios RJ, Foster BA, Demayo F, Greenberg NM (2008)
Hill DJ, Sedran RJ, Brenner SL, McDonald TJ (1997)
Bagley CJ, May BL, Szabo L, McNamara PJ, Ross M, Francis GL, Ballard FJ, Wallace JC (1989)
McGrath MF, Collier RJ, Clemmons DR, Busby WH, Sweeny CA, Krivi GG (1991)
+ 26 more citations
Related Resources
Quick Facts
Formula
~7.4 kDa (67 AA)
Molecular Weight
7.6
Sequence
MGKISSLPTQLFKCCFCDFLKVKMHTMSSSHLFYLALCLLTFTSSATAGPETLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSARSVRAQRHTDMPKTQKYQPPSTNKNTKSQRRKGWPKTHPGGEQKEGTEASLQIRGKKKEQRREIGSRNAECRGKKGK
Mechanism
Fast-acting IGF-1 for localized muscle hypertrophy effects
Safety Information
Research compound only. ANGIOGENESIS/CANCER CONCERN - Potential tumor promotion. WADA BANNED. NOT approved for human use.
Citations
31Guan J, Williams CE, Skinner SJ, Mallard EC, Gluckman PD (1996)
Kaplan-Lefko PJ, Sutherland BW, Evangelou AI, Hadsell DL, Barrios RJ, Foster BA, Demayo F, Greenberg NM (2008)
Hill DJ, Sedran RJ, Brenner SL, McDonald TJ (1997)
Bagley CJ, May BL, Szabo L, McNamara PJ, Ross M, Francis GL, Ballard FJ, Wallace JC (1989)
McGrath MF, Collier RJ, Clemmons DR, Busby WH, Sweeny CA, Krivi GG (1991)
+ 26 more citations