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IGF-1 LR31 mg

Modified growth factor analog. Lyophilized powder for reconstitution.

What it is

IGF-1 LR3, or Long R3 IGF-I, is a modified analog of human insulin-like growth factor 1. Arginine replaces glutamate at position 3 and a 13-residue extension is added at the N-terminus, changes that sharply lower its affinity for IGF binding proteins. It is used chiefly as a research reagent in cell culture, livestock physiology and animal models.

Class
Growth Hormone Secretagogues
Formula
IGF-1 LR3 · 1 mg
Format
Lyophilized powder

How it works

IGF-1 LR3 is a modified analog of insulin-like growth factor 1, engineered for extended activity in research.

IGF-1

The growth mediator

IGF-1 is the main downstream mediator of growth hormone, signaling cell growth and protein synthesis.

LR3

Built to last longer

The LR3 modification reduces binding to IGF binding proteins, extending the analog's active life in study models.

Anabolic

Studied in muscle models

Research examines IGF-1 LR3 for satellite cell activation and muscle protein synthesis pathways.

Key benefits

  • Growth-and-performance research focused on lean mass and muscle growth.
  • Recovery and body-composition protocols using growth-factor signaling.
  • Studied as a downstream growth-factor option, not a GH-releasing one.

Laboratory research only. Not for human or veterinary use.

What published research is studying

Preclinical research
  • Organ and tissue growth responses to IGF analogs in animal models
  • Interaction with IGF binding proteins and the availability of free IGF in vitro
  • Feedback effects on the somatotropic axis, including growth hormone and endogenous IGF-I, in livestock
  • Amyloid pathology and cognition in transgenic mouse models of Alzheimer's disease
  • Detection of the analog in seized products, for doping-control laboratories

There are no published human clinical trials of Long R3 IGF-I, and the animal results are not uniformly anabolic, with growth suppressed rather than increased in pigs.

Key research findings and references

Key research findings

In female guinea pigs infused for 7 days, LR3 IGF-I increased the fractional weights of adrenals, gut, kidneys and spleen. Body weight gain and feed intake did not change significantly.

Conlon MA et al., J Endocrinol 1995

In finisher pigs, a 4-day infusion of LR3 IGF-I decreased average daily gain, feed intake, plasma insulin, IGFBP-3 and endogenous IGF-I. Mean growth hormone fell 23% and the area under growth hormone peaks fell 60%.

Dunaiski V et al., J Endocrinol 1997

In male 5XFAD mice treated intranasally from 3 to 10 months of age, LR3 IGF-1 reduced filamentous amyloid plaques in cortex. It did not preserve performance on behaviour and memory assays.

Engel MG et al., J Alzheimers Dis 2025

Analysis of an injection vial from the black market identified His-tagged Long-R3-IGF-I, a form normally made for biochemical studies. Its effects in humans have not been described.

Kohler M et al., Growth Horm IGF Res 2010

Published study duration

  • Guinea pig infusion study: 7 days of continuous infusion (Conlon 1995).
  • Finisher pig infusion study: 4 days (Dunaiski 1997).
  • Mouse Alzheimer model: 7 months of intranasal treatment, from 3 to 10 months of age (Engel 2025).

Research endpoints

  • Fractional organ weights and carcass composition
  • Plasma IGF-I, IGF-II and IGFBP-3 concentrations
  • Average daily gain and feed conversion efficiency
  • Mean growth hormone concentration and area under growth hormone peaks
  • Amyloid-beta plaque profile and behavioural memory testing

References

  1. Conlon MA et al., J Endocrinol 1995. Long R3 IGF-I infusion stimulates organ growth in the guinea pig
  2. Dunaiski V et al., J Endocrinol 1997. Long [R3] IGF-I reduces growth and plasma GH in pigs
  3. Engel MG et al., J Alzheimers Dis 2025. Intranasal long R3 IGF-1 and amyloid plaque remodeling in 5XFAD mice
  4. Kohler M et al., Growth Horm IGF Res 2010. Detection of His-tagged Long-R3-IGF-I in a black market product
  5. Hammon H et al., Am J Physiol 1997. The somatotropic axis in neonatal calves modulated by nutrition, GH and Long-R3-IGF-I

Summaries of published research, for context only. Research use only. Not for human or veterinary use.

premium-grade research peptides

IGF-1 LR31 mg

Modified growth factor analog. Lyophilized powder for reconstitution.

Choose your vial

Choose strength
Quantity
1 vial

Add 2 more, save 5%

1 × IGF-1 LR3 · 1 mg€120 / vial
€120

Free1 × 3 ml bacteriostatic water · 10 × 0.5 ml syringes · 10 × alcohol swabs · uu.life research handling card

  • €130 to free shipping
  • Ships in 1-2 business days
  • Discreet EU

What you get

  • 1 × IGF-1 LR3 · 1 mg
  • Medical supply kitFreeOne kit with every vial1 × 3 ml bacteriostatic water10 × 0.5 ml syringes10 × alcohol swabs
  • uu.life research handling card

One supply kit ships with every vial: the counts above follow the quantity.

Optional spare suppliesHow To Use The Vials

The standard supplies above ship free with every vial. Add extras only if the research plan needs more.

Independently lab tested
99%+ purity standard
Identity verified by LC-MS
Batch COA available
Tracked delivery to European Union

Research handling

Full handling guide
  1. 01

    Lyophilized, sealed, batch-numbered

    Each vial ships as a freeze-dried powder under an inert seal, tied to the batch on its Certificate of Analysis.

  2. 02

    Store cold and dark

    Unopened vials are kept refrigerated at 2-8°C away from light. Reconstituted material is stored refrigerated and used within the window the research plan defines.

  3. 03

    Reconstitute with bacteriostatic water

    The included bacteriostatic water is added slowly down the vial wall and the vial is swirled, never shaken.

  4. 04

    Research use only

    Supplied for laboratory research. Not for human or veterinary use. Handle with the personal protective equipment the laboratory requires.

Before you order

What ships in the box?

The vials selected, plus a free supply kit with every vial: one 3 ml bacteriostatic water, ten 0.5 ml syringes and ten alcohol swabs per vial, and the uu.life research handling card.

How does volume pricing work?

The price per vial depends on how many vials of the same strength are on the line. 3-4 vials take 5% off, 5 or more take 10% off. The discount is applied automatically and shows on the product page, in the cart and at checkout.

Is every batch tested?

Yes. Every batch is tested by an independent laboratory for identity and purity, and the Certificate of Analysis is linked from this page and the lab-testing library.

How fast is delivery?

Orders are typically dispatched within 1-2 business days and arrive across most of Europe in 3-5 business days, tracked, in discreet packaging. Orders over €250 ship free, and Shipping Protection can be added at checkout.

Is this for human use?

No. Every product is sold for laboratory research only and is not for human or veterinary use.

Ready to order IGF-1 LR3?

Choose a strength and quantity above. Volume pricing applies automatically.

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Quality you can trace.

Batch-tested purity

Every vial ships with a Certificate of Analysis from an independent third-party lab. No exceptions.

Fast shipping

Orders are typically dispatched within 1-2 business days. Most European deliveries arrive in 3-5 business days.

Replacement guarantee

Arrived damaged? Send photos and the order number and a replacement is arranged.

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