IGF-1 LR3 FAQ: common questions answered
An unapproved growth signal with no human trials found.
Also called: Long R3 IGF-I, Long Arg3 IGF-1, LR3-IGF-1, Long-[Arg3]IGF-I.
IGF-1 and analogues · Modified IGF-1 receptor agonist · Evidence: Animal studies only.
- Is IGF-1 LR3 FDA-approved? No FDA-approved LR3 product. A research label is not authorization for human use.
- How do people take it? Under the skin, once daily. The review describes 4–6 weeks on followed by the same time off.. Source: reported by users, not an established dose.
- What's the difference between IGF-1 LR3 and Somatropin? IGF-1 LR3: an unapproved growth signal with no human trials found. Somatropin: prescription human growth hormone, with no proven anti-aging benefit. Why people pair them: people seek more growth signalling and muscle gain.
- Can I take it with Growth hormone? People seek more growth signalling and muscle gain. No LR3 combination trial; fluid retention and blood-sugar effects may add. Source: reported by users. Ask a doctor before combining anything.
- Is it banned in sport? Yes. It is banned in and out of competition (WADA 2026). IGF-1, mecasermin and IGF-1 analogues are prohibited in and out of competition.
- How long does a mixed vial last? Posts advise refrigeration; a reliable post-mixing shelf life is unknown.
Related to IGF-1 LR3
- Mecasermin: Prescription IGF-1 approved for rare childhood growth failure; low blood sugar is a major risk.
- Retatrutide: An experimental weekly injection with phase 3 weight-loss results.
- Somatropin: Prescription human growth hormone, with no proven anti-aging benefit.
Sources
- 21 CFR 216.23 — Bulk drug substances that can be used to compound drug products in accordance with section 503A of the Federal Food, Drug, and Cosmetic Act., Office of the Federal Register · eCFR · 2026
- 503B Bulk Drug Substances List, FDA · FDA · 2026
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act, FDA · FDA · 2026
- Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act, FDA · FDA · 2026
- Cellulitis, NHS · NHS · 2026
- The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
- Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026, Australian Government · Australian Government · 2026
- INCRELEX (mecasermin) injection, for subcutaneous use, U.S. Food and Drug Administration · FDA · 2025
- Anaphylaxis, NHS · NHS · 2023
- Low blood sugar (hypoglycaemia), NHS · 2023
- Tailor Made Compounding LLC - 594743 - 04/01/2020, FDA · FDA · 2020
- Increlex, European Medicines Agency
- Increlex, INN-mecasermin, European Medicines Agency
- Know When to Go to the ER, American College of Emergency Physicians · American College of Emergency Physicians
- Mecasermin (Increlex▼): risk of benign and malignant neoplasia, MHRA
Sources checked: 2026-10-18.
Information only, not medical advice. Peptifacts does not sell anything and does not link to sellers.