IGF-1 DES: The Emptiest Evidence File of Any Compound We Track

Last Updated: October 2026

No human clinical trial of IGF-1 DES has ever been published, and 3 independent lab tests and 2 in-stock shops are the whole of its market record on this platform (verified October 2026) — the thinnest human-and-market file of any compound in our growth hormone peptides category. What it does have is a defined structure and a real preclinical pedigree going back to the late 1980s.

That combination is the point of this page: the molecule and its design rationale are genuine and documented in the primary literature, while the human evidence behind the muscle-growth claims made for it is zero. We separate the two below, and we do it beside the compound's better-covered sibling, IGF-1 LR3.

The short version

• IGF-1 DES is native human IGF-1 with its first three amino acids (Gly-Pro-Glu) deleted, leaving a 67-residue protein with the same three disulfide bridges.

• Its signature property — much weaker binding to IGF-binding proteins than native IGF-1 — is established in preclinical biochemistry (Ross 1989; Oh 1993; Tomas 1992), not vendor lore, but it has never been tested in a human.

• No human clinical trial, no published human pharmacokinetics, and no marketing authorisation exist for IGF-1 DES anywhere as of October 2026.

• The platform holds only 3 lab tests (98.88% average HPLC purity, all overweight) and 2 shops in stock at $28 and $45 per milligram (verified October 2026) — and a mass-spectrometry identity check matters more here than a purity number.

• It is prohibited in sport at all times under WADA, and it is named by sequence analogue in published anti-doping blood-detection methods.

How much human evidence exists for IGF-1 DES?

None specific to the molecule. No human clinical trial of IGF-1 DES has been published, no human pharmacokinetic profile exists, and no dose-ranging or safety study of this specific analogue has been registered or reported as of October 2026. The preclinical record is real — rat and cell-culture work from the late 1980s and 1990s — but every statement about what DES does in a person is an extrapolation from animals or from native IGF-1, not a measured human result.

What this means in practice: the compound is sold for a use nobody has tested in humans, on the strength of a mechanism that was characterised in rats. That is not the same as "no evidence" — it is a specific, and much narrower, kind of evidence. The sections below mark which tier each claim rests on.

What is IGF-1 DES, structurally?

IGF-1 DES is des(1-3)IGF-I — native human IGF-1 with the first three residues, Gly-Pro-Glu, removed. Native IGF-1 is a 70-amino-acid chain with three intramolecular disulfide bridges; deleting the N-terminal tripeptide leaves 67 residues beginning TLCGAELVDALQ, with all three disulfide bridges intact. The mature parent sequence, residues 49–118 of Insulin-like growth factor 1 (UniProt P05019), begins Gly-Pro-Glu:

GPETLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA

The deletion is the whole design. Removing Gly-Pro-Glu is what gives DES its defining behaviour — it is the N-terminal region implicated in binding-protein interaction — and the compound exists to exploit that. The native molecular weight, 7,649 Da, is the figure the mecasermin prescribing information (INCRELEX) publishes for the parent; the ~283-dalton loss of the tripeptide is simple arithmetic, but no regulator or pharmacopoeia has issued a reference mass for DES itself, which is why this article does not print one as a specification.

Does IGF-1 DES really bind IGF-binding proteins weakly?

Yes, and this is the one claim about DES with solid primary support — in animals and cells, not humans. In serum, most IGF-1 travels bound to IGF-binding proteins (IGFBPs), which hold it inactive; the deletion of Gly-Pro-Glu sharply reduces that binding, leaving more of the molecule free. This is not vendor marketing: it is reported in the peer-reviewed biochemistry, which is exactly why the claim deserves to be stated plainly rather than hedged.

The foundational result is Insulin-like growth factor (IGF)-binding proteins inhibit the biological activities of IGF-1 and IGF-2 but not des-(1-3)-IGF-1 (Ross et al., Biochemical Journal, 1989): binding proteins suppressed native IGF-1's activity but not the truncated form's. Characterization of the affinities of insulin-like growth factor (IGF)-binding proteins 1-4 for IGF-I, IGF-II, IGF-I/insulin hybrid, and IGF-I analogs (Oh et al., Endocrinology, 1993) placed the responsible region in the first residues of the B-domain — the ones DES removes — and showed those residues matter for binding-protein attachment but not for binding the IGF-1 receptor. Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats (Tomas et al., Biochemical Journal, 1992) found the truncated and extended analogues both bound IGFBPs poorly and were more anabolic than native IGF-I in rats. What none of these did was measure any of it in a human.

The receptor side is the necessary counterpart: because DES keeps the receptor-binding surface and loses the binding-protein surface, preclinical work describes it as more potent than native IGF-1 in some cell and animal systems. "More potent in a dish" is a measured finding; "more locally active in a person," the usual grey-market framing, is not — no human study has measured where DES acts or for how long.

Is IGF-1 DES shorter-acting than IGF-1 LR3?

No human study has compared them, but animal data exist — so this is not pure marketing, as is sometimes claimed, nor is it a human finding. DES and LR3 are the two IGF-1 analogues sold in this market, reached by opposite structural routes: DES deletes the first three residues, while LR3 adds a 13-residue N-terminal extension and substitutes position 3. Both bind IGF-binding proteins poorly by design, and in rats the free, poorly-bound forms clear faster than native IGF-1.

Plasma clearance and tissue distribution of labelled insulin-like growth factor-I (IGF-I), IGF-II and des(1-3)IGF-I in rats (Ballard et al., Journal of Endocrinology, 1991) found that des(1-3)IGF-I stayed largely unbound in plasma and was cleared several-fold faster than native IGF-I, with the kidney taking up the most — and the authors noted that rapid clearance could limit, not extend, the analogue's effect in the body. A later rat study measured the clearance of IGF-I, des(1-3)IGF-I and LR3IGF-I side by side. The "DES is the short, local one; LR3 is the long, systemic one" division rests on these animal differences and on the molecules' design, never on a head-to-head human comparison, because none has been run.

What is known about IGF-1 in humans — through the one approved product?

Everything known about IGF-1 in a monitored human population comes from mecasermin, native IGF-1, which is a different molecule from DES. Mecasermin (INCRELEX, BLA 021839, approved 30 August 2005) is recombinant human IGF-1 indicated for growth failure in children with severe primary IGF-1 deficiency or with a GH gene deletion who have developed neutralising antibodies to GH. Its mean terminal half-life is 5.8 hours after a single 0.12 mg/kg subcutaneous dose, and it is given at 0.04–0.12 mg/kg twice daily with food, in a supervised paediatric setting.

That supervision exists because of the safety profile. The label reports hypoglycaemia in 42% of subjects — "Hypoglycemia was reported by 30 subjects (42%) at least once," with five severe episodes and four hypoglycaemic seizures or losses of consciousness — a figure that sits in the clinical-trials section (6.1), while section 5.1 carries the standing hypoglycaemia warning. The label also records tonsillar hypertrophy in 15% of subjects in the first one to two years, intracranial hypertension, slipped capital femoral epiphysis, scoliosis progression and anaphylaxis, and it lists malignant neoplasia as a contraindication. Contrary to a claim repeated across peptide sites, INCRELEX carries no boxed warning — the hypoglycaemia risk is handled in Warnings and Precautions, not a boxed warning.

Stop and seek care: swelling of the face or throat, difficulty breathing or hives after an injection are signs of a serious allergic reaction; spreading redness, warmth or pus at an injection site with fever is an infection; severe or persistent abdominal pain with vomiting on a GLP-1 drug can be pancreatitis; confusion, sweating or shaking on an IGF-1 or insulin-adjacent compound can be hypoglycaemia. Call your local emergency number (911 in the US, 112 in the EU, 999 in the UK, 000 in Australia) or go to an emergency department, and bring the vial and its label. Research-use vials are not approved products in any jurisdiction, even where a prescription product of the same molecule exists; no article on this site replaces a clinician who knows your history.

That is native IGF-1, with normal binding-protein interaction, in a monitored population, at doses an approval defined. DES is engineered to raise the free fraction, has never been studied in a human, and is self-administered from research vials.

Which IGF-1 DES claims survive the evidence?

The structure and the binding-protein mechanism survive as preclinical facts; everything about human effect and safety does not. The honest reading is not "it does nothing" — the design is coherent and documented — but "none of it has been shown in a person." The table below separates the biochemistry, which is real, from the human claims, which are absent.

Can a certificate of analysis confirm you have IGF-1 DES?

Not on its own, and purity cannot stand in for identity here. A 67-residue protein with three disulfide bridges behaves like a protein, not a short peptide: its activity depends on the bridges forming in the correct pairing, and a misfolded molecule has exactly the same mass as a correctly folded one. A high HPLC purity number tells you a sample is homogeneous; it tells you nothing about whether the one molecule present is correctly folded DES, or even DES at all.

The identity risk is not hypothetical. At least one research-reagent listing sold under the name "IGF-1 DES" actually carries the LR3 construct — an 83-residue chain of roughly 9,100 daltons, not the 67-residue ~7,370-dalton DES — a mismatch of about 1,700 daltons that any mass-spectrometry check would expose immediately and that a purity figure never would. That is the practical case for insisting on mass-based identity: see Mass Spectrometry for Peptides for what the method confirms, and why a peptide can be 99 percent pure and still be entirely the wrong molecule for why a clean chromatogram is not reassurance.

Because mass alone cannot confirm folding, and no authoritative reference mass exists, a DES certificate is weaker evidence than one for a small, well-characterised peptide — the recycled-graph and cropped-report tricks catalogued in Red Flags in Peptide Certificates of Analysis (CoA) matter even more when the honest certificate can prove so little.

What do three lab tests and two shops actually tell you?

Very little, and that scarcity is itself the finding. IGF-1 DES records 3 independent lab tests from 2 laboratories, averaging 98.88% HPLC purity, with all three samples overweight (+3% to +7.4% of label) — and it is listed by 90 shops but in stock at only 2, at $28 and $45 per milligram (verified October 2026). Three tests is three data points, not a dataset: no claim about typical vendor quality for this compound can be drawn from it in either direction.

For scale, IGF-1 LR3 carries 141 tests and the better-covered compounds far more, against a platform total of 13,478 independent lab tests across 118 peptides and 782 shops (verified October 2026). The price layer is just as thin: a median computed from two in-stock listings is barely a median, and the platform flags it as such. These figures exclude shipping, taxes, customs and bulk tiers — compare what is on file through Peptide Lab Tests, the composite purity picture at The Peptigrity Purity Index, and current cost through the peptide price comparison layer, each of which holds more for almost any other compound than it does for this one.

Where does IGF-1 DES stand with regulators and anti-doping?

Unapproved everywhere, on no FDA compounding list, and prohibited in sport at all times. IGF-1 DES is not on the FDA list of bulk drug substances that may present significant safety risks — neither its 14-substance Category 2 table nor its 17-substance nominated-but-withdrawn table (page current 22 April 2026, unchanged after the July 2026 compounding-committee meeting), and no IGF-1 analogue appears anywhere on it. That absence is not clearance: DES is not a component of any approved drug, has no pharmacopoeial monograph, and is not on the 503A bulks list, which makes it an unapproved new drug.

In sport, the World Anti-Doping Agency prohibits "Insulin-like growth factor 1 (IGF-1, mecasermin) and its analogues" at all times under the growth-factor section of its Prohibited List, alongside mechano growth factors, thymosin-β4 and others — wording unchanged between the 2026 and 2027 lists. This is more than category coverage: the 2022 method paper Probing for peptidic drugs (2–10 kDa) in doping control blood samples (Thomas & Thevis, Analytical Science Advances) names "Des1-3-IGF-I" specifically, alongside long-R3-IGF-I and R3-IGF-I. Testing laboratories have published methods for finding it, as Do Peptides Show Up on Drug Tests? sets out.

The trial that would settle this

A real evidence file for IGF-1 DES would have to start with a published mass and folding specification, because there is no authoritative reference standard against which to test a batch. After that, the human studies the compound has never had: a Phase 1 with pharmacokinetics and glucose monitoring, IGF-binding-protein interaction measured in people rather than inferred from rats, a head-to-head against IGF-1 LR3 to test the shorter-acting framing, and growth-plate and malignancy-relevant safety monitoring drawn from what the approved parent's label already warns about.

None of that exists today. For the compound that at least has a registered human safety trial behind its parent and a measured molecular-weight problem of its own, the companion piece is IGF-1 LR3: The Molecular Weight Nobody Can Source — and the Identity Test It Blocks.

Frequently Asked Questions

What is IGF-1 DES?

IGF-1 DES is des(1-3)IGF-I — native human IGF-1 with the first three residues, Gly-Pro-Glu, removed, leaving a 67-residue protein with the same three disulfide bridges. It is one of two IGF-1 analogues sold in this market, the other being IGF-1 LR3. It has a defined structure and a preclinical research record, but no approved medical use anywhere.

Does IGF-1 DES actually bind IGF-binding proteins less than normal IGF-1?

Yes — this is the best-supported claim about it, in animals and cells. Peer-reviewed work from 1989 onward shows the deletion of the first three residues sharply reduces binding-protein attachment while leaving receptor binding intact (Ross 1989; Oh 1993). What has never been measured is whether, or how, that translates into any effect in a human.

Has IGF-1 DES been tested in humans?

No. No human clinical trial of IGF-1 DES has been published, and there is no human pharmacokinetic, dose-ranging or safety study of this specific molecule as of October 2026. Everything known in a monitored human population comes from mecasermin, native IGF-1, which is a different, approved molecule.

Is IGF-1 DES shorter-acting than LR3?

No human study has compared them. In rats, both analogues bind binding proteins poorly and clear faster than native IGF-1, and one study measured DES and LR3 clearance side by side; the "DES is the shorter, more local one" framing rests on those animal findings and on the molecules' design, not on any human comparison.

What do the purity numbers tell me?

Very little. Three tests from two laboratories is not enough to characterise vendor quality in either direction, and for a 67-residue protein, purity cannot confirm identity or correct disulfide folding — a misfolded or wrong molecule can return a clean, high-purity chromatogram at an identical mass. Mass spectrometry, not a purity percentage, is the check that matters here.

Is IGF-1 DES banned in sport?

Yes. The World Anti-Doping Agency prohibits IGF-1 "and its analogues" at all times under the growth-factor section of its Prohibited List, and des(1-3)IGF-I is named specifically in published doping-control blood-detection methods.

When should I talk to a clinician?

Before using any IGF-1 analogue if you have any history of cancer, diabetes or insulin resistance, or an unexplained reaction to a previous injection — IGF-1 lowers blood glucose, and the approved parent drug lists malignant neoplasia as a contraindication. Confusion, sweating or shaking after a dose can be hypoglycaemia and is a reason to seek care, not to wait it out.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use; research peptides are sold for laboratory use and are not manufactured, tested or labelled to pharmaceutical standards. Peptigrity does not recommend doses: every dose figure above is an approved-label value, a published-trial value or a community report, and is labelled as such — a community report is not a recommendation. Self-injection carries risks of infection, allergic reaction and dosing error; signs of a serious allergic reaction, an injection-site infection with fever, severe abdominal pain, or confusion and sweating on an IGF-1 or insulin-adjacent compound are medical emergencies — call your local emergency number. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.