Ask your doctor,.

There is None that work anywhere near as well

The one supplement that works "similarly" is Milk Thistle - I take it myself

But and this is a big BUT - if you actually "need" metformin then a whole bottle of milk thistle would not provide the same benefit as a single 500 mg tablet of metformin

The reason why "meds" were developed was because the "traditionals/naturals" just didn't work well enough - and they had 3000 years to try and find a natural solution - its just not there

Metformin IS a traditional (French lilac plant) that "kinda" worked in it's traditional form but it had to be pharmaceutically produced for it to be "effective"

If you need the meds, take them or you will mess yourself up badly

If you get control through diet, exercise and Weight Loss (biggest factor - you will never likely get control without meds if you are overweight) and you want a little help then take the milk thistle or the chromium or cinnamon or any of the dozens of other naturals/traditions that "do a little" - which was better than nothing

Back when (before 1921 when insulin was discovered) if you got diabetes you DIED 100% of the time. Some of these naturals would give you an extra year or two but they didn't "treat"

If you have diabetes and want to live and need the "meds" - take them