Awesome post, thanks Ryan! This has been a hobby of mine for some time and I am particularly interested in the medical applications of different plants/roots/herbs. I'm currently in medical school and I spend a lot of time finding the latest research on the aforementioned. There are many I would like to mention here but fear doing so because of their potent effects, many contraindications, and limited scientific research. Furthermore, different people metabolize compounds at different rates making the dosing tricky. Here is one book on the subject I could recommend though; it lists many different herbs, their anecdotal use, what the current evidence says, the quality of the current evidence, and safety: https://www.amazon.com/Phytopharmacy-Evidence-Based-Herbal-Medicinal-Products/dp/1118543564/
One thing I think worth mention: Many studies have found that cinnamon may improve glucose regulation in a dose-dependent manner (don't go crazy please). Mechanism is thought to be due to increased glucagon-like peptide 1, which stimulates glucose-dependent insulin secretion. See https://www.ncbi.nlm.nih.gov/pubmed/21480806 , https://www.ncbi.nlm.nih.gov/pubmed/22579946

