Switching from semaglutide to tirzepatide often restarts the weight loss trajectory, presumably by engaging additional receptor pathways that monotherapy does not activate
In MCAS, mast cellswhich line the blood vessels, nerves, and mucosal tissuesbecome hyper-responsive, inappropriately releasing massive amounts of histamine, cytokines, and other inflammatory mediators in response to minor environmental or internal triggers
However, it has not achieved the same level of success as stand-alone GLP-1 receptor agonists like semaglutide and dulaglutide
The initial weight loss often includes water weight as tirzepatide reduces food intake and begins altering metabolic function
Eli Lilly, which manufactures tirzepatide, said it replicated the finding and published an open letter calling for a nationwide recall of tirzepatide products containing untested additives
However, we did observe higher increases in serum calcitonin levels, a tumor marker for medullary thyroid carcinoma, with increased doses of tirzepatide compared to placebo