IGF-1 DES(1,3) vs IGF-1 LR3
Two IGF-1 analogs engineered to slip past the same binding-protein brake, one by subtracting mass and one by adding it; the real difference is duration, not evidence.
Short answer
Neither IGF-1 DES(1,3) nor IGF-1 LR3 has much human evidence; both are graded preclinical / minimal, so trials cannot say which works better. IGF-1 DES(1,3) is the one sold for local muscle growth, while IGF-1 LR3 targets muscle growth. Both are sold gray-market as research chemicals.
IGF-1 DES(1,3)
A truncated IGF-1 that escapes its binding proteins, so it's more potent in cells and animals — but there are zero human muscle trials, and the IGF-axis cancer concern applies.
Full IGF-1 DES(1,3) evidence reviewIGF-1 LR3
An engineered long-acting IGF-1 with zero human muscle-building trials; the risks (hypoglycemia, the growth-factor/cancer concern, a WADA ban) follow straight from the biology.
Full IGF-1 LR3 evidence reviewIGF-1 DES(1,3) vs IGF-1 LR3: head to head
- FDA status / approved use
IGF-1 DES(1,3)
Not an approved drug; sold as a research chemical; prohibited in sport by WADAIGF-1 LR3
Unapproved research-grade product; prohibited at all times in sport under WADA- Marketed for
IGF-1 DES(1,3)
Local muscle growthIGF-1 LR3
Muscle growth- Outcome areas
IGF-1 DES(1,3)
Muscle / strength / lean massIGF-1 LR3
Muscle / strength / lean mass- Evidence grade
IGF-1 DES(1,3)
Preclinical / minimalIGF-1 LR3
Preclinical / minimal- How it works
IGF-1 DES(1,3)
Truncated IGF-1 that escapes binding proteins, so more stays free and activeIGF-1 LR3
Long-acting IGF-1 analog that evades binding proteins, extending anabolic growth signaling- Route and dosing
IGF-1 DES(1,3)
Injection, often into a specific muscleIGF-1 LR3
Injection; no established human dose- Headline human result
IGF-1 DES(1,3)
Not establishedIGF-1 LR3
Not established- Strongest evidence
IGF-1 DES(1,3)
Ballard, Int J Biochem Cell Biol 1996. Little or no controlled human outcome data for the marketed useIGF-1 DES(1,3) evidence reviewPubMed 8930132IGF-1 LR3
Watts, Int J Epidemiol 2023. Little or no controlled human outcome data for the marketed useIGF-1 LR3 evidence reviewPubMed 35726641- Key safety signal
IGF-1 DES(1,3)
Low blood sugar (hypoglycemia) and cancer concern from raising IGF signaling; no human safety dataIGF-1 LR3
Hypoglycemia; chronically raising IGF-1 is tied to higher cancer risk- How it is obtained
IGF-1 DES(1,3)
Sold gray-market as a research chemical; no approved or legitimately compounded human productIGF-1 LR3
Sold gray-market as a research chemical; no approved or legitimately compounded human product
| IGF-1 DES(1,3) | IGF-1 LR3 | |
|---|---|---|
| FDA status / approved use | Not an approved drug; sold as a research chemical; prohibited in sport by WADA | Unapproved research-grade product; prohibited at all times in sport under WADA |
| Marketed for | Local muscle growth | Muscle growth |
| Outcome areas | Muscle / strength / lean mass | Muscle / strength / lean mass |
| Evidence grade | Preclinical / minimal | Preclinical / minimal |
| How it works | Truncated IGF-1 that escapes binding proteins, so more stays free and active | Long-acting IGF-1 analog that evades binding proteins, extending anabolic growth signaling |
| Route and dosing | Injection, often into a specific muscle | Injection; no established human dose |
| Headline human result | Not established | Not established |
| Strongest evidence | Ballard, Int J Biochem Cell Biol 1996. Little or no controlled human outcome data for the marketed useIGF-1 DES(1,3) evidence reviewPubMed 8930132 | Watts, Int J Epidemiol 2023. Little or no controlled human outcome data for the marketed useIGF-1 LR3 evidence reviewPubMed 35726641 |
| Key safety signal | Low blood sugar (hypoglycemia) and cancer concern from raising IGF signaling; no human safety data | Hypoglycemia; chronically raising IGF-1 is tied to higher cancer risk |
| How it is obtained | Sold gray-market as a research chemical; no approved or legitimately compounded human product | Sold gray-market as a research chemical; no approved or legitimately compounded human product |
marks a row where the two differ. “Not established” marks a cell the available evidence does not answer. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
- Preclinical / minimal:
- Evidence is largely animal, in-vitro, or anecdotal. Little or no controlled human outcome data for the marketed use.
Our verdict
There is no evidence winner here, because neither has any. Both are research-only IGF-1 analogs with zero controlled human trials for muscle, recovery, or performance; the entire case for each rests on cell and animal potency. DES(1,3) is IGF-1 with its first three amino acids clipped off, which weakens binding-protein affinity and leaves it short-acting, the basis of the site-specific pitch; LR3 reaches the same escape by adding an arginine substitution plus a 13-residue extension, making it long-acting and systemic. Both carry the same mechanistic risks, insulin-like hypoglycemia and the IGF-axis cancer concern, and both are prohibited at all times in sport under WADA; neither is an approved or prescribable product.
IGF-1 DES(1,3) fits if
Read the DES page if you want to understand how a three-residue truncation changes potency and clearance, and why a short half-life is a pharmacologic property rather than proof of a local muscle effect.
IGF-1 LR3 fits if
Read the LR3 page if the question is what a deliberately long-acting, systemic IGF-1 signal means, including that LR3 was built as a laboratory cell-culture reagent, not a therapeutic for injection into people.
IGF-1 DES(1,3) vs IGF-1 LR3: common questions
- Is either IGF-1 DES(1,3) or IGF-1 LR3 FDA-approved?
- No. IGF-1 DES(1,3) is not an approved drug; sold as a research chemical; prohibited in sport by WADA. IGF-1 LR3 is an unapproved research-grade product; prohibited at all times in sport under WADA.
- Which has stronger human evidence, IGF-1 DES(1,3) or IGF-1 LR3?
- Neither. Both are graded preclinical / minimal, with little or no controlled human outcome data for the marketed use. The key source for IGF-1 DES(1,3) is Ballard, Int J Biochem Cell Biol 1996; for IGF-1 LR3, it is Watts, Int J Epidemiol 2023.
- What are the main safety concerns with IGF-1 DES(1,3) and IGF-1 LR3?
- For IGF-1 DES(1,3), watch for low blood sugar (hypoglycemia) and cancer concern from raising IGF signaling; no human safety data. For IGF-1 LR3, watch for hypoglycemia; chronically raising IGF-1 is tied to higher cancer risk.
Key studies behind each
IGF-1 DES(1,3)
- Ballard FJ, Wallace JC, Francis GL, Read LC, Tomas FM. (1996). Des(1-3)IGF-I: a truncated form of insulin-like growth factor-I. Int J Biochem Cell Biol. PubMed 8930132
- Yamamoto H, Murphy LJ. (1995). Enzymatic conversion of IGF-I to des(1-3)IGF-I in rat serum and tissues: a further potential site of growth hormone regulation of IGF-I action. J Endocrinol. PubMed 7561610
- Tomas FM, Knowles SE, Owens PC, et al. (1991). Increased weight gain, nitrogen retention and muscle protein synthesis following treatment of diabetic rats with insulin-like growth factor (IGF)-I and des(1-3)IGF-I. Biochem J. PubMed 1710892
- Ballard FJ, Knowles SE, Walton PE, et al. (1991). Plasma clearance and tissue distribution of labelled insulin-like growth factor-I (IGF-I), IGF-II and des(1-3)IGF-I in rats. J Endocrinol. PubMed 2005410
IGF-1 LR3
- Gellhaus B, Böker KO, Schilling AF, et al. (2023). Therapeutic Consequences of Targeting the IGF-1/PI3K/AKT/FOXO3 Axis in Sarcopenia: A Narrative Review. Cells. PubMed 38132107
- Watts EL, Perez-Cornago A, Fensom GK, et al. (2023). Circulating insulin-like growth factors and risks of overall, aggressive and early-onset prostate cancer: a collaborative analysis of 20 prospective studies and Mendelian randomization analysis. Int J Epidemiol. PubMed 35726641
- Bang P, Polak M, Bossowski A, et al. (2023). Frequency and Predictive Factors of Hypoglycemia in Patients Treated With rhIGF-1: Data From the Eu-IGFD Registry. J Clin Endocrinol Metab. PubMed 37579214
- Laron Z, Werner H. (2021). Laron syndrome - A historical perspective. Rev Endocr Metab Disord. PubMed 32964395
The full evidence reviews
- IGF-1 DES(1,3): a more potent, truncated IGF-1 — untested in people
DES(1,3) IGF-1 is IGF-1 with its first three amino acids clipped off — a naturally occurring, more potent variant that escapes the binding proteins holding IGF-1 in reserve. It's real biology, but there are zero human muscle-building trials, and the risks (hypoglycemia, the growth-factor/cancer concern, a WADA ban) follow straight from the molecule.
Updated August 2026
- IGF-1 LR3: a real anabolic hormone, engineered to last — and untested in people
IGF-1 is a genuine anabolic hormone and “Long R3” is engineered to dodge its binding proteins so it lasts far longer. But there are zero human muscle-building trials — and the risks (hypoglycemia, the growth-factor/cancer concern, a WADA ban) follow straight from the biology.
Updated August 2026
Where to get it
Where to get peptide therapy
Clinician-led telehealth services that prescribe compounded peptides. The specific peptides offered vary by provider — confirm IGF-1 DES(1,3) availability before ordering.
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