Neuroscientist Dr. Andrew Huberman discussed retatrutide with Gwyneth Paltrow, highlighting this new triple-agonist GLP-1 therapy. Unlike earlier weight-loss drugs that caused rapid caloric deficits and significant muscle loss, retatrutide activates GIP, GLP-1, and glucagon receptors to regulate blood sugar, appetite, and metabolism with a lower side effect profile. Huberman noted it has a "muscle sparing effect," allowing users to lose up to one-third of their body weight over a year without aggressive resistance training.
Retatrutide is administered as a once-weekly subcutaneous injection in clinical trials.
A gray market of compounding pharmacies and online peptide suppliers has emerged amid demand. Huberman warned against unregulated sources, citing potential bacterial toxins like LPS that cause inflammation. Paltrow compared the situation to the 1990s supplement landscape lacking third-party testing.
Retatrutide is an investigational molecule legally available only in Lilly-sponsored trials. It has not been approved by any regulatory agency. Experts advise against using any product claiming to be retatrutide outside of clinical studies.