IGF-1 LR3

A lab-made, longer-acting version of IGF-1 used mostly to grow cells in labs. Human research on injecting it is essentially absent.

Evidence: Primarily preclinical research
Half-life: Not known
Sources: 2 cited

Is IGF-1 LR3 FDA-approved?

Not approved by the FDA. Products sold online as "research chemicals" aren't checked for purity, sterility or dose.

Is IGF-1 LR3 banned in sport?

Banned in sport by the World Anti-Doping Agency (WADA).

Overview

IGF-1 LR3 has 13 extra amino acids and one swap, so the proteins that normally hold IGF-1 in check can't bind it. That makes it much more potent in lab dishes, where it's used to grow cells. The approved IGF-1 medicine (mecasermin) is a different, natural-sequence product.

How it works

It switches on IGF-1 receptors but escapes the binding proteins that usually limit IGF-1, so more of it stays active.

How long does IGF-1 LR3 stay in the body?

Not established in people.

What it's studied for

Cell culture
Gut growth in young animals

Reported side effects

Low blood sugar is the main known risk of IGF-1 drugs

Sources

The studies and prescribing labels this page is written from.