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IGF-1 LR3

Muscle growth, recovery, hyperplasia. Categorized as a Growth Factor peptide.

Also known as: Insulin-like Growth Factor 1 Long R3

Updated: 2026-04-03
3 cited studies

What Is IGF-1 LR3?

IGF-1 LR3 (Insulin-like Growth Factor 1 Long R3) is classified as a growth factor peptide. IGF-1 analog with extended half-life for muscle cell hyperplasia (new cell creation, not just hypertrophy). Promotes nitrogen retention and protein synthesis.

It is extensively evaluated in laboratory and clinical settings for its potential to drive muscle growth, recovery, hyperplasia. Researchers target IGF-1 LR3 for its ability to interact with specific cellular and molecular pathways, making it a compound of significant interest across multiple therapeutic domains.

Potent; use caution. Risk of hypoglycemia. Theoretical cancer promotion concern well-documented in literature. Research-only.

How Does IGF-1 LR3 Work?

IGF-1 analog with extended half-life for muscle cell hyperplasia (new cell creation, not just hypertrophy). Promotes nitrogen retention and protein synthesis.

At the molecular level, IGF-1 LR3 operates through pathways characteristic of the Growth Factor class. By interacting with target receptors and downstream signaling cascades, the compound initiates biological responses associated with muscle growth, recovery, hyperplasia.

Expected Research Timeline

Weeks 2–4

Lean mass and recovery improvements; possible hypoglycemia if undereating

Months 2–3

Significant body composition changes; hyperplasia (new cell creation) possible

Long-Term

Theoretical cancer promotion risk with chronic use; short cycles essential

What Does the Research Say?

The following are key findings from peer-reviewed studies on IGF-1 LR3, indexed on PubMed and equivalent databases:

Safety & Side Effects

Potent; use caution. Risk of hypoglycemia. Theoretical cancer promotion concern well-documented in literature. Research-only.

Side EffectIncidenceSeverity
Hypoglycemia~10% of usersmoderate
Joint pain~8% of usersmild
Headache~5% of usersmild
Fluid retention~10% of usersmild

FDA Status: Not Approved for Human Therapeutic Use

IGF-1 LR3 is not currently FDA-approved for human use. It is available for research purposes only. Always consult a licensed healthcare provider.

How Is IGF-1 LR3 Used?

Route

SubQ

Dose Range

5050 mcg

Frequency

5x/wk

Cycle

4–4 wk

Timing: Post-workout

Notes: Very low doses. Inject post-workout for localized muscle effects. Monitor blood sugar closely. Short cycles only.

All dosing information reflects parameters reported in published research literature and is not intended as clinical guidance. Usage of any peptide should be supervised by a qualified healthcare professional.

IGF-1 LR3 vs. Related Compounds

CompoundPrimary Use
IGF-1 LR3(this page)Muscle growth, recovery, hyperplasia
CJC-1295Muscle growth, fat loss, recovery
Follistatin-344Muscle hypertrophy, strength

Where to Source IGF-1 LR3 for Research

Purchasing ultra-high purity, laboratory-grade peptides is critical for verifiable research. We only recommend vendors providing independent, third-party HPLC Certificates of Analysis (COA).

View COA-Verified IGF-1 LR3
✓ Third-party tested✓ US shipping

Disclosure: PeptiDex may earn a commission from purchases. This does not affect our recommendations. We exclusively feature vendors that pass our strict quality verification protocols.

Frequently Asked Questions

What is IGF-1 LR3?

IGF-1 LR3 is a growth factor peptide. IGF-1 analog with extended half-life for muscle cell hyperplasia (new cell creation, not just hypertrophy). Promotes nitrogen retention and protein synthesis.

What are the primary research benefits of IGF-1 LR3?

Published research identifies primary mechanisms targeting: Muscle growth, recovery, hyperplasia. These findings come from 3+ peer-reviewed studies indexed in our database.

What is the half-life of IGF-1 LR3?

In published pharmacokinetic data, IGF-1 LR3 demonstrates a half-life of approximately 20 hours.

Is IGF-1 LR3 FDA approved?

IGF-1 LR3 is not currently FDA-approved for human therapeutic use. It is classified as a research compound and is studied under investigational protocols. Always consult a healthcare provider.

What are common side effects of IGF-1 LR3?

Reported side effects in published literature include Hypoglycemia (~10% of users), Joint pain (~8% of users), Headache (~5% of users), Fluid retention (~10% of users). Most are classified as moderate in severity.

How is IGF-1 LR3 administered?

In research settings, IGF-1 LR3 is typically administered via SubQ. Very low doses. Inject post-workout for localized muscle effects. Monitor blood sugar closely. Short cycles only.

Sources

  1. IGF-1 LR3 promotes muscle growth in animal models. View on PubMed
  2. IGF-1 signaling: muscle repair and regeneration review. View on PubMed
  3. IGF-1 and cancer risk comprehensive epidemiological review. View on PubMed
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Medical Disclaimer

The information provided in this profile is for educational and research purposes only. IGF-1 LR3 is not FDA-approved for human therapeutic use. Nothing on this page should be interpreted as medical advice. Always consult a licensed healthcare professional before interacting with any peptide compound. Read our full disclaimer.

Last updated: 2026-04-03 · About PeptideX · Editorial Standards