Indeed, it is not practically feasible to measure intraluminal production fluxes of various metabolites in vivo in humans
These include alcohol, opioids, and nicotine (and, anecdotally, online gambling, skin-picking, excessive shopping, and other non-substance related compulsive behaviors)
There has also been reporting and industry advocacy that some of the Category 2 peptides could be reclassified to Category 1, which would restore their eligibility for legal compoundingbut no formal FDA rule has been published, those peptides remain Category 2 and restricted for now, and the regulatory status of peptides can change, so verify current FDA status before acting
Shieh A, Greendale GA, Cauley JA, Karvonen-Gutierrez CA, Karlamangla AS
The study included 6 clinical strategies: UC, UC plus diet and exercise, UC plus semaglutide, UC plus tirzepatide, UC versus laparoscopic sleeve gastrectomy, and UC plus Roux-en-Y gastric bypass
Fixed-dose and fixed-ratio combination therapies in type 2 diabetes