Lab / animal only Performance and Recovery
IGF-1 LR3
Also called Long R3 IGF-I; Long Arg3 IGF-I
A modified IGF-1 used in lab research. It is biologically active, but muscle-building, recovery and anti-aging claims are not established, and it is not the approved IGF-1 medicine.
Overview
What it is
IGF-1 with a 13-amino-acid extension and an arginine substitution at position 3, which weakens binding to IGF-binding proteins.
How it works
More of it stays free to activate the IGF-1 receptor. In rat muscle cells it stimulated protein and DNA synthesis more than native IGF-1, but it was less potent in cells that lack binding proteins, so "more potent" is conditional.
What the research shows
In guinea pigs, organ size changed relative to body weight without a significant change in overall weight gain or body composition. A pig study found weight-gain results opposite to promotional claims. No human treatment studies were identified.
Studied for
- Protein synthesis in muscle cellslab
- Tissue growthguinea pigs, pigs
Safety and regulatory status
Safety and side effects
No measured human side-effect rates. The related medicine mecasermin carries warnings for severe low blood sugar with seizures, allergic reactions, raised skull pressure, lymphoid tissue growth and cancer. Confusion, collapse or seizure after an injection needs urgent care.
Regulatory status
Not FDA approved (FDA warning letter, 2020). Prohibited at all times by WADA as an IGF-1 analogue.
Mixing and dosing reference
Reference information only. Read before using this section.
Reference information only. Not instructions. These mixing and dosing figures summarize published studies and third-party protocols so you can understand the research. They are not medical advice, not a recommendation that anyone use any substance, and not a treatment plan. They do not apply to Research Products, which are for laboratory research only and must never be used in humans or animals. Never self-administer any compound. Only a licensed healthcare professional who has evaluated you can decide whether a medication is appropriate and how it should be used.
IGF-1 LR3 (1 mg Vial) Dosage Protocol
- Vial
- 1 mg IGF-1 LR3
- Add diluent
- 3 mL
- Concentration
- 0.33 mg/mL
- 1 unit (U-100)
- 3.33 mcg in 0.01 mL
- Route
- Subcutaneous
- How often
- Once per day subcutaneously; timing often aligned with meals (morning or post-workout) to manage insulin-like effects.
- Typical range
- 20–50 mcg once daily subcutaneously (gradual titration recommended).
Standard / Gradual Approach
| 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) |
How to mix
- Draw 3.0 mL bacteriostatic water with a sterile syringe.
- Inject slowly down the vial wall to avoid foaming; do not shake.
- Gently swirl or roll until the lyophilized powder dissolves completely into a clear solution.
- Label the vial with reconstitution date and refrigerate at 2–8 °C (35.6–46.4 °F), protected from light. Follow a validated product-specific use-by period; aliquoting or freezing does not establish an extended use-by without stability data.
Dosing details
- Start (Weeks 1–2): 20 mcg daily to assess tolerance, particularly regarding blood glucose effects.
- Titrate (Weeks 3–4): Increase to 40 mcg daily if Week 1–2 well-tolerated with no significant hypoglycemic symptoms.
- Maintain (Weeks 5–8): Hold at 50 mcg daily; this is considered the conservative upper end for most research protocols.
- Frequency: Once per day subcutaneously; timing often aligned with meals (morning or post-workout) to manage insulin-like effects.
- Site Rotation: Rotate injection sites systematically (abdomen, thighs, upper arms) to prevent local irritation or lipohypertrophy.
Storage
- Lyophilized (unopened): Store at −20 °C (−4 °F) or colder (−80 °C optimal) in dry, dark conditions; follow the exact product’s labeled storage conditions and validated shelf life.
- Reconstituted solution: Refrigerate at 2–8 °C (35.6–46.4 °F) immediately after mixing; follow a validated use-by period for the exact formulation.
- Extended storage: Do not assume sterile aliquots or freezing extend stability or sterility without exact-formulation data. Never refreeze a thawed vial.
- Handling: Allow frozen vials to reach room temperature before opening to minimize condensation; always inspect solution for clarity (discard if cloudy or contains particles).
- Protection: Keep all vials protected from light and maintain cold chain during storage.
Administration technique
- Subcutaneous injection guidance based on clinical best practices.
- Wash hands thoroughly with soap and water.
- Clean the vial stopper with an alcohol swab; allow to air dry completely.
- Ensure the reconstituted solution is clear with no visible particles; discard if cloudy.
- Draw the calculated dose into a sterile insulin syringe (29–31 gauge, ½ inch or 5/16 inch needle).
- Remove air bubbles by gently tapping the syringe and pushing plunger until solution is at the correct measurement.
- Site selection: Choose areas with adequate subcutaneous fat - abdomen (2+ inches from navel), outer thighs, upper arms, or upper outer buttocks.
- Clean injection site: Swab with alcohol and allow to dry completely (do not fan or blow on site).
- Pinch technique: Gently pinch a fold of skin between thumb and forefinger to ensure subcutaneous placement.
- Needle insertion: Insert needle at 45–90° angle into the pinched skin fold (45° for thin individuals; up to 90° for those with more subcutaneous fat).
- Injection: Do not aspirate for subcutaneous injections; slowly depress plunger to inject peptide solution over 2–3 seconds.
- Withdrawal: Remove needle at the same angle it entered; apply gentle pressure with a clean cotton ball or swab (do not rub vigorously).
- Disposal: Immediately place used syringe/needle in a sharps container without recapping.
- Maintain a rotation pattern across multiple sites (e.g., left abdomen → right abdomen → left thigh → right thigh).
Important notes
- Sterile technique: Always use new, sterile insulin syringes for each injection; dispose immediately in a sharps container. Follow “one needle, one syringe, only one time” practice.
- Site rotation: Systematically rotate injection sites between abdomen (at least 2 inches from navel), outer thighs, and upper arms to reduce local irritation and prevent tissue hardening.
- Injection technique: Inject slowly and steadily; wait a few seconds before withdrawing the needle to prevent solution leakage.
- Hypoglycemia awareness: Be vigilant for signs of low blood sugar (shakiness, dizziness, sweating) especially during dose escalation; have fast-acting carbohydrates readily available.
- Timing with meals: Administer with or shortly after food intake to mitigate insulin-like effects on blood glucose.
- Documentation: Keep a daily log of dose, injection site, and any observed effects to maintain protocol consistency and identify tolerance patterns.
- Never exceed conservative dosing: Doses above 50–60 mcg/day lack robust clinical research support and may substantially increase adverse effect risk.
Protocol source: PeptideDosages.com
Common questions
Is IGF-1 LR3 growth hormone?
No. It is an IGF-1 analogue.
Does it raise testosterone?
That has not been shown.
Does a purity certificate prove safety?
No. It only shows what was in the tested sample.
Related in Performance and Recovery
Sources and further reading (5)
- Francis GL, et al. Recombinant fusion protein analogues of IGF-I, 1992.
- DailyMed. Increlex (mecasermin) prescribing information.
- FDA. Tailor Made Compounding warning letter, April 2020.
- WADA. 2026 Prohibited List, S2.
- Source summary: PeptideDosages.com research overview (rewritten for NVO).
Laboratory research material: IGF-1 LR3 Research Use Only
Educational information only. This content summarizes published research for general education. It is not medical advice, not a recommendation to use any substance, and not an instruction for human or animal use. It does not describe any Research Product sold on this site.