Retatrutide is an investigational peptide drug developed by Eli Lilly that acts as a triple agonist, simultaneously targeting three hormone receptors: glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon receptors
study timeline, Fig
Full-length growth hormone produces fat loss but also elevates IGF-1 (with implications for cell proliferation and aging), worsens insulin sensitivity and elevates blood glucose (problematic for diabetics and pre-diabetics), promotes muscle growth and protein synthesis (which may be desired or unwanted depending on goals), causes fluid retention and edema in many users, and requires careful medical monitoring with regular blood work
Now, researchers are also examining whether B12 status may influence hormones as well
The compound was developed by the Australian biotech firm Metabolic Pharmaceuticals as a research tool to isolate the lipolytic signaling domain of growth hormone without the receptor-binding region responsible for its anabolic and glucose-handling effects
It also helps to correct severe deficiencies very quickly (if the deficiency is not based on genetic abnormalities which may require a specific form(s) of B12)