Growth hormone
IGF-1 DES
A shortened IGF-1 analogue with altered binding-protein interactions; greater activity in a cell assay did not translate into better neuroprotection in a rat study.
Cell potency experiment plus rat brain-injury comparison; no clinical efficacy validation
Also known as: Des(1–3) IGF-1 · des-IGF-1
Practical use
Evidence interpretation and clinical context
- Verify the molecular variant
- Native IGF-1 and des(1–3) IGF-1 require separate evidence.
- Keep potency in context
- A cell-assay comparison is not a clinical effect size.
- Read negative comparisons
- The rat neuroprotection result limits a simple stronger-is-better claim.
A key functional role for the insulin-like growth factor 1 N-terminal pentapeptide.
Overview
Des(1–3) IGF-1 lacks the first three amino acids of the native peptide. Its lower affinity for some IGF-binding proteins can change the amount available to act in particular experimental systems.
Risks and limitations
The cited cell and animal studies do not establish a safe human product, exposure pattern or therapeutic indication. Altering binding-protein interactions can change tissue targeting as well as apparent potency.
How to read this
Binding proteins are not simply obstacles to remove. They can limit activity in one assay and help direct an IGF signal to the right tissue in another setting.
Research explained
A key functional role for the insulin-like growth factor 1 N-terminal pentapeptide.
Who was studied
Rat muscle-cell assays comparing native IGF-1 with several N-terminally shortened analogues.
What was found
Des(1–3) IGF-1 stimulated protein synthesis at lower concentrations than native IGF-1 in the assay, largely associated with reduced binding-protein interaction.
What it cannot establish
Cell-culture potency is context dependent. It does not establish a corresponding multiplier for human muscle gain.
Read the original studyThe effects of insulin-like growth factor (IGF)-1, IGF-2, and des-IGF-1 on neuronal loss after hypoxic-ischemic brain injury in adult rats: evidence for a role for IGF binding proteins.
Who was studied
Adult rats with experimentally induced hypoxic-ischemic brain injury.
What was found
Native IGF-1 reduced neuronal loss. Des-IGF-1 did not reproduce that protection across the principal comparisons; a higher-exposure group showed only a trend.
What it cannot establish
The experiment used direct central administration in injured animals. It does not establish a human brain or muscle treatment.
Read the original studyCurrent clinical boundary
The sources reviewed here are experimental studies and do not establish an approved des-IGF-1 product or a human benefit-risk profile.
Supporting sourceWhy greater free activity may not mean greater benefit
The brain-injury comparison suggested that binding proteins can help target protective IGF effects. Less binding was not uniformly advantageous.
Supporting sourceClaims versus findings
Unsupported conversion
Higher cell-assay potency means proportionally more human muscle growth.
The reported potency concerns protein synthesis in cultured rat cells, not human hypertrophy.
Check the evidenceCommon questions
Is des-IGF-1 interchangeable with native IGF-1?
The different results in the rat brain-injury study argue against assuming equivalent biological effects.
SourceSources
A key functional role for the insulin-like growth factor 1 N-terminal pentapeptide.
Sources checked 2026-10-01.
General education; not a personal treatment plan.