How approved GLPS compare to such RUOs as Retatrutide
1) You can hit a “satiety ceiling,” so the difference you feel shrinks Both tirzepatide and retatrutide activate GLP-1 pathways that reduce appetite via gut–brain signalling and central satiety circuits. Once someone has been on high-dose therapy, appetite and cravings may already be strongly suppressed (and eating patterns already adapted), so moving to another incretin drug may produce less noticeable incremental appetite change—even if weight loss continues. GLP-1 appetite effects are well-established and partly central (brain) and partly peripheral (GI). Translation: if hunger is already “turned down to 2/10,” it’s hard to feel a new drug turning it down further—even if metabolism is changing. 2) The “fullness” sensation from slowed gastric emptying often attenuates with time A big part of early appetite suppression on GLP-1–based therapy is slower gastric emptying (food stays in the stomach longer → earlier fullness). But multiple clinical and peri-operative reviews note that the gastric-emptying delay can attenuate with ongoing treatment (often framed as tachyphylaxis/attenuation), meaning the dramatic early “I can’t eat” feeling is less prominent later. So if someone is coming from prolonged/high-dose tirzepatide, they may: - already be adapted to the gastric-emptying effect, and - perceive retatrutide as “less appetite suppressing,” even if it’s still effective. (There is debate on how complete this attenuation is across drugs and measurement methods, but attenuation is commonly described clinically.) 3) Retatrutide’s extra weight effect isn’t only appetite — it likely adds energy expenditure via glucagon biology Retatrutide is a triple agonist (GLP-1 + GIP + glucagon receptors), unlike tirzepatide (GLP-1 + GIP). That glucagon-receptor component is important because glucagon signalling can: - increase energy expenditure/thermogenesis (context-dependent), - increase fat oxidation and shift fuel use, - counterbalance some of the metabolic “slow-down” that comes with weight loss.