Peptide Graded

All peptides / Muscle and bone

IGF-1 DES

IGF-1 analog

Also IGF-1 DES(1-3), DES(1-3) IGF-1, des(1-3)IGF-1, IGF1 DES, IGF-1 DES 1-3, Des IGF-1

Evidence
CAnimal and cell studies
FDA status
Not approvedas of 2026-10-26
Route
Injection
Studies cited
0 human2 animal or cell

It is sold as an injection for local muscle growth. It acts strongly on cells in a dish, but it has never been tested in people.

Sold for

IGF-1 DES is sold as a fast-acting, locally injected form of IGF-1 for muscle growth at the injection site.

Studies say

Cell studies explain why des(1-3)IGF-1 is more potent than IGF-1 in a dish, but there are no human studies at all, so the grade is C.

Why grade C. For the muscle-growth use it is sold for, the cited evidence is biochemical: cell assays showing des(1-3)IGF-1 escapes the binding proteins that restrain normal IGF-1, and one rat study in kidney insufficiency. No human has been given des(1-3)IGF-1 in a published study. 12

FDA. IGF-1 DES, the des(1-3) fragment of insulin-like growth factor 1, is not approved by the FDA for any use and is sold online as a research chemical. 1

Written from 3 cited sources. Fact-checked 2026-10-27: 10 claims checked, 4 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for
Building muscle
Can a US doctor prescribe it?
No. It is not approved and is sold as a research chemical.
Properly tested in people?
Not properly: animal or lab studies, or small uncontrolled human reports. No human has been studied.

Evidence checklist

  • Randomised controlled trial No human studyno
  • Human study over 100 people No human studyno
  • More than one research group Cell and animal work onlyno
  • Clinical outcomes, not surrogate markers No clinical outcome measuredno
  • Human safety data beyond case reports No human safety datano

Drawn from the cited studies below. A dash means the sources give no information.

What it is

IGF-1 DES is insulin-like growth factor 1 with its first three amino acids removed. This form occurs naturally in small amounts in the brain and in bovine colostrum. Ballard and Francis's group in Adelaide characterised it in the late 1980s. They were looking at why colostrum stimulated cell growth more than expected. 1

Full-length IGF-1 circulates bound to binding proteins. These keep most of it inactive and extend its life in the blood. Losing the three N-terminal residues removes a key contact point for those proteins. So des(1-3)IGF-1 binds them weakly. It acts on cells more strongly and more briefly. This is the basis of the online claim that it works "locally". 1

How it works

Ross and colleagues showed that IGF binding proteins inhibit the activity of IGF-1 and IGF-2 in cell assays. They do not inhibit des(1-3)IGF-1. Its affinity for the IGF-1 receptor is roughly the same as native IGF-1. The extra potency comes entirely from not being sequestered by binding proteins. Once on the receptor, it triggers the same tyrosine kinase cascade as IGF-1. That promotes cell growth and survival. 1

What human research shows

There are none. A 1991 rat study gave des(1-3)IGF-1 to young rats with part of their kidneys removed. It found better weight gain and nitrogen balance, with less muscle protein breakdown. A 2026 review in Frontiers in Endocrinology covers the IGF-1 lab-made versions circulating as research chemicals. But no human study of des(1-3)IGF-1 has been published. 23

StudyModelFinding
Ross 1989, binding proteinsCell culture assays with purified IGF binding proteinsIGF binding proteins inhibited IGF-1 and IGF-2 activity but not des(1-3)IGF-1, explaining its higher potency. 1
Martin 1991, rats with reduced kidney massAnimal study, young male rats after partial nephrectomy, 7 daysIGF-1 and des(1-3)IGF-1 increased weight gain and nitrogen balance; des(1-3)IGF-1 reduced the rate of muscle protein breakdown. 2

Safety

Nothing is known from human use. The expected risks are those of IGF-1 itself. One is low blood sugar, since IGF-1 at high concentrations acts on insulin receptors. The other is a theoretical boost to tumour growth. A version that evades binding proteins would be expected to cause sharper low blood sugar. Nobody tests online products for identity or purity. 13

Questions for your clinician

  • Has IGF-1 DES ever been given to people in a trial?
  • What would the risk of low blood sugar be with this form?
  • Are there approved options for the goal I have in mind?

Questions people ask

Is IGF-1 DES FDA-approved?

No. It has no approved use anywhere and is sold as a research chemical. Full-length recombinant IGF-1 (mecasermin) is approved for children with severe IGF-1 deficiency. That is a different product. 1

Why is IGF-1 DES said to be more potent than IGF-1?

It does not bind the IGF binding proteins that hold most circulating IGF-1 in reserve. In cell assays the free peptide acts more strongly for that reason. It does not bind the receptor any better. 1

Does it work locally at the injection site?

That claim is an inference. It rests on the peptide's short life in the blood and its lack of binding-protein buffering. No study has tested whether injecting it into a muscle produces local growth in animals or people. 13

Citations

  1. Ross 1989, Biochemical Journal: IGF binding proteins inhibit IGF-1 and IGF-2 but not des(1-3)IGF-1 doi.org
  2. Martin 1991, Am J Physiol: IGF-I and its variant des-(1-3)IGF-I enhance growth in rats with reduced renal mass doi.org
  3. Dominikowski 2026, Front Endocrinol: performance-enhancing peptides that act on the GH-IGF-1 axis, review doi.org

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