IGF-1 LR3 — Literature-Reported Ranges & Study Protocols

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Every figure on this page is a range reported in published literature or in a publicly documented study protocol. It is a record of what researchers used, not a recommendation, a therapeutic protocol, or advice. Peptide Intel Hub is an independent publication, sells nothing, and describes these compounds as in-vitro research reagents only.

Compound at a glance

Class: Modified insulin-like growth factor 1 analogue
Reported half-life: Approximately 20–30 hours (versus ~15 minutes for native IGF-1)
Routes used in the literature: Subcutaneous in animal work; it is primarily a cell-culture reagent
Also written as: Long R3 IGF-1

What the published studies reported

Each row below describes one body of work. The model and population are part of the figure — a rodent per-kilogram quantity and a human trial quantity are not comparable.

Cell-culture supplementation (its designed use)

Reported quantity: 1–100 ng/mL in media, commonly 10 ng/mL
Frequency: Per media change
Study duration: Continuous across the culture period

This is by far the largest and most reliable body of quantitative data for the molecule.

Rodent growth and muscle models

Reported quantity: Reported around 10–50 µg/kg/day in the animal literature
Frequency: Once daily, or continuous by osmotic minipump
Study duration: 1–4 weeks

Native IGF-1 studies dominate; LR3-specific in-vivo data is sparse.

Dosage chart

These figures match the published chart for this compound on peptidedosages.com, including the reconstitution volume, resulting concentration, insulin-syringe units and the staged schedule. Educational reference only — not instructions, and not medical advice.

IGF-1 LR3 · 1 mg Vial

IGF-1 LR3 is dosed at 20 mcg–50 mcg daily via subcutaneous injection in educational protocols. A 1 mg vial reconstituted with bacteriostatic water yields about 0.333 mg/mL. This information is for research and educational use only.

Reconstitute: Add 3.0 mL bacteriostatic water → ~0.333 mg/mL concentration (333 mcg/mL).
Typical daily range: 20–50 mcg once daily subcutaneously (gradual titration recommended).
Easy measuring: At 0.333 mg/mL, 1 unit = 0.01 mL ≈ 3.33 mcg on a U-100 insulin syringe.
Storage: Lyophilized: freeze at −20 °C (−4 °F) for up to 12 months; after reconstitution, refrigerate at 2–8 °C (35.6–46.4 °F) and use within 30 days; avoid repeated freeze–thaw cycles.

Standard / Gradual Approach (3 mL = ~0.333 mg/mL)

Week	Daily Dose (mcg)	Units (per injection) (mL)
Weeks 1–2	20 mcg (0.02 mg)	6 units (0.06 mL)
Weeks 3–4	40 mcg (0.04 mg)	12 units (0.12 mL)
Weeks 5–8	50 mcg (0.05 mg)	15 units (0.15 mL)

Source chart on peptidedosages.com

Mixed with 3 ml of bacteriostatic water

The same arithmetic for every vial size IGF-1 LR3 is supplied in, using a fixed 3 ml of bacteriostatic water. One unit on a U-100 insulin syringe is 0.01 ml, so the unit column below is simply the volume that carries the reported amount. Educational arithmetic only — not instructions, and not medical advice.

IGF-1 LR3 · 3 ml bacteriostatic water

Vial size	Concentration	Per 1 unit	20 mcg =	50 mcg =
0.1 mg	0.03 mg/ml	0 mcg	60 units	150 units
1 mg	0.33 mg/ml	3 mcg	6.0 units	15 units

Unit columns use the range reported for this compound (20 mcg–50 mcg). Only the vial sizes this compound is actually supplied in are shown, and every figure assumes exactly 3 ml of bacteriostatic water. For any other volume, use the reconstitution calculator.

Reconstitution maths

Commonly 1 mg vials. Reconstituted in 1 mL gives 1 mg/mL — a 100,000-fold higher concentration than typical culture use, so culture work requires serial dilution.

Open the reconstitution calculator

How to read these figures

Reduced binding-protein affinity is the whole point of the molecule and also why it behaves unlike native IGF-1 in an organism.
IGF-1 signalling is central to the cancer-biology literature; the risk discussion is not hypothetical.
It is acid-sensitive and usually reconstituted in dilute acetic acid rather than plain water.

Sources and citations

These are the published records the figures on this page are drawn from. Each one describes what researchers administered, in which model or population, and over what period. Quantities reported in a study are specific to that study's design and are not transferable guidance.

[1]
Insulin-like growth factor-I (IGF-I) analogue, LR3IGF-I, ameliorates the loss of body weight but not of skeletal muscle during food restriction
Tomas FM, Lemmey AB, Read LC, Ballard FJ. · Growth Hormone & IGF Research · 2001 · PMID 11472075
Rats under food restriction received continuous subcutaneous infusion of the IGF-1 analog LR3-IGF-I to evaluate effects on body weight and skeletal muscle mass.
View the record
[2]
IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep
Al-Juboori SI, Wesolowski SR, Limesand SW, Brown LD, Rozance PJ. · American Journal of Physiology-Endocrinology and Metabolism · 2024 · PMC11901354
Growth-restricted fetal sheep received continuous intravenous infusion of IGF-1 LR3 to test effects on fetal growth in late gestation.
View the record

Search the databases yourself

Read the IGF-1 LR3 research brief

Other growth hormone compounds

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All research protocols

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