igf-1 lr3 kick in time LR3: muscle growth, or just hype?, A peptide often mentioned muscle growth circles — but what does the science actually say about IGF-1 LR3?, IGF-1 stands for Insulin Growth Factor 1, a 𝗜 𝗱𝗲𝗰𝗶𝗱𝗲𝗱 𝘁𝗼 𝘁𝗮𝗸𝗲 𝗮

First characterised in receptor pharmacology studies published in the late 1990s (DOI 10.1046/j.1365-2265.1998.00629.x), ipamorelin was specifically designed to improve on the selectivity limitations of earlier GHRPs such as GHRP-2 and hexarelin, both of which produced meaningful elevations of cortisol and prolactin alongside GH stimulation

Both Sermorelin and Tesamorelin are GHRH analogs that act on the same pituitary receptor

thyroid, kidney, or liver dysfunction, skin rash, and complications with intravenous catheters such as infection and inflammation of the vein

Mild side effects (water retention, tingling, slight hunger increase) don't require stopping

Elevated insulin-like growth factor 1 receptor signaling induces antiestrogen resistance through the MAPK/ERK and PI3K/Akt signaling routes