IGF-1 LR3 (Long R3 IGF-1) — Dosing, Cycles, Half-Life & Side Effects

IGF-1 LR3 (Long R3 IGF-1) is a growth-factor peptide with a half-life of 20-30 hours. Modified IGF-1 with extended half-life due to arginine substitution at position 3 and 13 amino acid extension. Does not bind to IGF binding proteins, remaining active longer and having more potent anabolic effects. This page is educational harm-reduction reference compiled from peer-reviewed literature — not medical advice, not an endorsement, not a recommendation to use. Consult a licensed clinician before any decision.

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Quick Facts

Class	Growth Factors
Half-life	20-30 hours
Hepatotoxicity	None
Suppression	0/10

Typical Dosing Ranges

Common dose range: 20-50mcg/day subcutaneous or intramuscular

Cycle length: 4-6 weeks (then break)

Dose ranges are compiled from published pharmacokinetic studies and community-reported usage. Where a value is community-reported rather than clinically studied, this page and its structured data flag it. Lower end of any range is always the safer starting point.

Stacking Considerations

No structural stacking blockers. Standard harm-reduction rules apply: minimize total androgen load, minimize oral exposure, and monitor bloodwork.

PCT Requirements

Never stack two SERMs. Extend a single SERM (tamoxifen OR enclomiphene/clomiphene) rather than combining.
Use the cycle planner to generate a full protocol based on your complete stack, not this compound alone.

Side Effect Profile

Potential hypoglycemia risk
May promote cancer growth (theoretical)
Not for use with pre-existing tumors
Can cause organ growth with chronic use
Expensive

Known Interactions

No compound-specific interactions are catalogued in the current matrix. This does not mean no risk exists — it means there is no curated pairwise entry.

Monitoring (Bloodwork & Vitals)

Comprehensive metabolic panel (baseline, mid-cycle, post-cycle)
Lipid panel (total cholesterol, HDL, LDL, triglycerides)
CBC (hemoglobin, hematocrit — watch for erythrocytosis)
Sex-hormone panel (Total T, Free T, Estradiol sensitive, SHBG, LH, FSH)
Blood pressure (weekly self-check; flag systolic >140 or diastolic >90)

Baseline bloodwork is recommended before any cycle. Discontinue if liver enzymes exceed 3× upper limit of normal or if hematocrit exceeds 54%.

Frequently Asked Questions

What is the half-life of IGF-1 LR3 (Long R3 IGF-1)?

IGF-1 LR3 (Long R3 IGF-1) has a half-life of approximately 20-30 hours. This figure is used to determine injection frequency (for esters) and post-cycle clearance timing.

What is the typical dose range for IGF-1 LR3 (Long R3 IGF-1)?

Commonly reported ranges for IGF-1 LR3 (Long R3 IGF-1): 20-50mcg/day subcutaneous or intramuscular. Cycle length: 4-6 weeks (then break). These are compiled from published studies and community-reported usage — individual response varies and lower end is always preferred.

Does IGF-1 LR3 (Long R3 IGF-1) suppress natural testosterone?

IGF-1 LR3 (Long R3 IGF-1) causes minimal suppression of the HPTA axis (score 0/10). PCT may still be advisable depending on stack and duration.

What is IGF-1 LR3 (Long R3 IGF-1) typically used for?

IGF-1 LR3 (Long R3 IGF-1) is commonly used for: Muscle growth, Recovery enhancement, Body composition. Intended-use context does not imply safety — every use case carries the same underlying pharmacological risks.

Is IGF-1 LR3 (Long R3 IGF-1) legal?

IGF-1 LR3 (Long R3 IGF-1) is a controlled substance in many jurisdictions (typically Schedule III in the US when it is an anabolic androgenic steroid). StackItSmart does not provide sourcing information. Possession, import, and use without a prescription carry legal consequences that vary by country and state.

Citations

Zapf J et al.. 1993. J Clin Invest — Native IGF-1 PK; LR3 variant has no published human RCT

Disclaimer

StackItSmart is an independent harm-reduction reference. The content above is compiled from peer-reviewed literature and is not medical advice, not an endorsement, and not a recommendation to use IGF-1 LR3 (Long R3 IGF-1). Performance-enhancing compounds carry legal, endocrine, cardiovascular, and hepatic risks. Consult a licensed clinician before any decision. StackItSmart does not provide sourcing, procurement, or dosing prescriptions.