I can’t speak for their effectiveness, but there are a number of supplements available on Amazon that contain Berberine, Ceylon Cinnamon, Turmeric, Curcumin, and several other things that are all supposed to aid in regulating blood sugar.
Although Metformin is considered relatively safe, Berberine is supposed to offer the same benefits naturally, from what I’ve read.
The biggest factor in combating high blood sugar, in my opinion, is diet. Dr. Sten Ekberg on YT has a number of great videos discussing this very topic and other health concerns. What I’ve seen from him made very good sense to me, and I have had good success recently in lowering my blood sugar by following his recommendations regarding diet. I don’t yet have any long term results, but what I’ve seen in the short time I’ve followed those recommendations is quite encouraging to me.
As I recall, Dr. Ekberg recommends cutting out sugar, grains, and starchy vegetables completely, and eating a low carb diet consisting primarily of vegetables that grow above ground, moderate proteins, and healthy fats. These foods do not readily convert to sugar in the body, so they minimize the body’s need to process the sugar from the foods that are consumed. Surprisingly, at least to me, the healthy fats are the foods that are least likely to convert to sugar.