Growth Hormone

Limited Research

IGF-1 LR3

IGF-1

Long-acting insulin-like growth factor analog.

Also known as: Long R3 IGF-1

Research dose range20–50 mcg daily (research models)

Route studiedSubcutaneous

Study durationDaily, shorter study blocks

Storage2–8 °C reconstituted

Overview

IGF-1 LR3 is a lengthened analog of insulin-like growth factor 1 studied for its extended half-life and role in cellular-growth research.

Key research findings

A long-acting analog of insulin-like growth factor 1 — the primary downstream mediator of growth hormone. The Arg3 substitution and 13-residue N-terminal extension reduce binding to IGF-binding proteins, dramatically extending its half-life and activity versus native IGF-1.

Mechanism of action

An 83-amino-acid analog with reduced binding-protein affinity, studied for prolonged IGF-1 receptor activation and growth signaling.

Molecular information

Weight9,111 Da

Length83 amino acids

TypeLong-acting IGF-1 analog

Native IGF-1 with an Arg³ substitution plus a 13-aa N-terminal extension (Long R3).

Pharmacokinetics

Peak: ~4–6 hoursHalf-life: ~20–30 hoursCleared: ~5 days

Peak · 0.2dHalf-life · 1d

Illustrative relative-concentration model derived from published pharmacokinetic research. Curve is normalized and provided for educational comparison only — not a dosing schedule.

Research applications

Cellular-growth research
Muscle-development studies
IGF-1 signaling investigations

Research protocols

Protocols summarized from published research models. Provided for scientific reference only — not dosing guidance for human use.

Research goalReference amountFrequencyRoute

Conservative referenceAmount: 20–30 mcgFrequency: Once dailyRoute: Subcutaneous

Standard referenceAmount: 40–50 mcgFrequency: Once dailyRoute: Subcutaneous

Observed effects timeline

Aggregated observations reported across research literature. Timing and magnitude vary by model and are not a guarantee of outcome.

Week 1–2
Onset of IGF-1-mediated anabolic signaling reported in study models.
Week 3–4
Tissue and recovery changes reported; cycles are typically kept short.

Research compatibility

Describes how compounds are studied alongside one another in the literature. Not a recommendation to co-administer.

HGH

Both elevate IGF-1 signaling; combined effects monitored in research.

Avoid combination

PEG-MGF

Related IGF-1 variants; overlapping pathways.

Use caution

Follistatin 344

Distinct (myostatin) pathway; co-studied in growth research.

Compatible

BPC-157

Popular healing stack. BPC-157 (250-500mcg 2x daily) with IGF-1 LR3 (40-60mcg daily) may accelerate tissue repair.

Synergistic

TB-500

Complementary healing mechanisms. TB-500 (2-5mg weekly) with IGF-1 LR3 enhances recovery through different pathways.

Synergistic

CJC-1295 / Ipamorelin

Both stimulate GH/IGF-1 axis. Combined use may cause receptor desensitization and compounded metabolic effects.

Use caution

How to reconstitute

Important

Reconstitute with bacteriostatic water (or, in some research, a dilute acetic-acid solution per protocol), swirl gently, and refrigerate. Do not shake.

1Allow the vial to reach room temperature (15–20 minutes).
2Swab the stopper with alcohol and let it air dry.
3Add the diluent slowly down the vial wall.
4Swirl gently until dissolved into a clear solution.
5Refrigerate at 2–8 °C and protect from light.

Open reconstitution calculator

Quality indicators

Uniform white powder

Lyophilized cake should be white to off-white without discoloration.

Clear solution

Reconstitutes to a clear, colorless, particle-free solution.

Cold-chain integrity

Reconstituted solution requires 2–8 °C storage.

Slight clumping

Small clumps that dissolve completely with gentle swirling are acceptable — shipping can cause minor compaction.

Collapsed or melted appearance

Powder that looks collapsed, melted, or stuck to the vial walls may have been exposed to heat in transit.

Cloudy after reconstitution

Persistent cloudiness, particles, or precipitate after gentle mixing can indicate a degraded or contaminated peptide.

Reported observations & safety

Safety signals reported in the research literature. Compiled for scientific awareness — not medical advice.

Hypoglycemia is a key reported risk due to IGF-1's insulin-like activity — glucose monitoring is emphasized in research.
Because IGF-1 is a general growth factor, theoretical proliferation risks are noted in the literature.

References & further reading

IGF-1 and Long R3 IGF-1 biology (review)

PreclinicalIGF-1growth signaling

Review of IGF-1 signaling and how the Long R3 modification extends activity by evading binding proteins.

View study

Topics

igf-1growth factorlong-acting

This entry is provided for educational and informational purposes only. It is not medical advice, a dosing protocol, or a claim of therapeutic benefit. Research compounds are supplied strictly for laboratory and research use — not for human or veterinary consumption.

Research level

Limited Research

Sparse published data; largely preliminary or anecdotal.

Quick reference

Dose range20–50 mcg daily (research models)

RouteSubcutaneous

DurationDaily, shorter study blocks

Storage2–8 °C reconstituted

Half-life~20–30 hours

Available at Reviva

IGF-1 LR3 is stocked as a research-grade compound, ≥98% by HPLC, third-party verified.

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