PeptideSearch

IGF-1 LR3

Animal studies only

Almost all the research is in animals. We do not know if the same thing happens in people.

Also called Long R3 IGF-1 / Insulin-like Growth Factor 1 Long R3

A modified growth factor that lasts longer in the body. Sold mainly as a cell-culture reagent.

Can a doctor prescribe this?

No. Pharmacies are not on record as being allowed to make this into a medicine.

The FDA has not approved this as a medicine.

Not approved and not on the compounding list. Widely sold as a laboratory reagent.

Official status: Not on the 503A bulks list. Checked 2026-08-04.

Lab suppliers we list: 12

Doses used in research

Taken word for word from the studies and trials listed on this page. This is not a recommendation and not a dose for anyone to take.

In animal studies

These are doses given to animals, usually per kilogram of body weight. They do not convert directly to a human dose.

  • See source wording

    sheep · into a vein

    IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep.American journal of physiology. Endocrinology and metabolism · 2025

    “We previously demonstrated that a 1-wk infusion of IGF-1 LR3, an IGF-1 analog with low affinity for IGF-binding proteins and high affinity for the IGF-1 receptor, at 6.6 µg·kg -1 ·h -1 into normal fetal sheep increased body weight but lowered insulin concentrations and GSIS.”