Hi Eric!
I suspect your question about quercetin and metformin is more in regards to healthspan improvement than diabetes management..is that correct?
The GLP-1 agonists are a much better option for both glucose control as well as likely for improving healthspan! BUT…they are cost-prohibitive for a lot of people so I will cycle metformin for people with high insulin or PCOS. continuous treatment is not good in my opinion. For instance in the brain, preclinical and preliminary clinical studies indicate that inhibition of mTORC1 can be beneficial for some pathological conditions such as epilepsy, cognitive impairment, and brain tumors, whereas stimulation of mTORC1 (direct or indirect) can be beneficial for other pathologies such as depression and axonal growth and regeneration. Similar issues for other tissues where we do not want continuous MTOR inhibition. For the autophagy effects, I prefer spermidine over quercetin or metformin and I cycle high dose for 6-8 weeks then lower maintenance dose.
Betsy