Garvey WT, Frias JP, Jastreboff AM, et Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2): a double-blind, randomised, multicentre, placebo- controlled, phase 3 trial
There is evidence that metformin can increase the abundance of microbiota which can all produce SCFAs such as Butyrivibrio , Bifidobacterium , Megasphaera , Prevotella , and so on (de la Cuesta-Zuluaga et al., 2017)
Not to mention the fact that your digestive system cannot absorb 100% of anything ingested
The best known figure in that cohort is the multimillionaire entrepreneur Bryan Johnson, whose eccentric longevity regime includes measuring his nightly erections and taking infusions of his teenage sons blood plasma