Encyclopedia · Growth Hormone & Performance

IGF-1 LR3

Evidence review

Evidence grade D

Evidence is primarily preclinical and often concerns a related molecule rather than the marketed name itself.

Reviewed Aug 10, 2026 3 linked authoritative sources

Long R3 IGF-I is a laboratory-engineered analogue of insulin-like growth factor 1 with reduced affinity for IGF-binding proteins. It is structurally and regulatorily distinct from mecasermin (Increlex), the approved recombinant human IGF-1 medicine.

IGF-1 LR3 is not approved mecasermin

Long R3 IGF-I is a laboratory-engineered analogue of insulin-like growth factor 1 with reduced affinity for IGF-binding proteins.[1] It is structurally and regulatorily distinct from mecasermin (Increlex), the approved recombinant human IGF-1 medicine.

Evidence is preclinical and indirect

Laboratory studies describe altered binding-protein interactions and biological potency for Long R3 IGF-I.[1] Teloryx found no controlled human clinical trial establishing IGF-1 LR3 for muscle gain, fat loss, recovery, healing, anti-aging, or any disease. Evidence about native IGF-1, IGF-1 gene expression, or mecasermin cannot be transferred to this analogue.

Related-drug risks do not create an LR3 safety profile

The current Increlex label includes hypoglycemia, hypersensitivity, intracranial hypertension, lymphoid-tissue hypertrophy, orthopedic complications, and malignant-neoplasia warnings.[2] Those are product-label findings for mecasermin, not measured incidence estimates for IGF-1 LR3. For LR3, human pharmacokinetics, dose-response, interactions, pregnancy effects, product quality, and long-term safety are unknown.

Regulatory and sport status

IGF-1 LR3 is not FDA-approved. Increlex is approved only for specified pediatric growth-failure conditions and does not validate LR3.[2] IGF-1 and its analogues are prohibited in tested sport.[3] Teloryx does not publish an LR3 dose, cycle, stack, or reconstitution recipe.

Evidence review

Sources and evidence

Citation numbers in the article link to the exact regulator records, trial registrations, and publications reviewed.

  1. Journal of Molecular EndocrinologyA potent analogue of human IGF-I with reduced affinity for binding proteins (1992)
  2. DailyMedIncrelex (mecasermin) official prescribing information (2025)
  3. World Anti-Doping Agency2026 Prohibited List (2026)