I have been trying half dose of Berberine every day. I have read and maybe all propaganda sales hype. It other health sites claim that it is as effective as metformin without any side effects of metformin. Although metformin has pretty few sides.
I have not gotten retested since I started the 500mg per day dose. So I have no data to support whether it is effective or not yet. If it shows signs of improvement, I will probanly up the dose to the recommended serving size listed on the bottle of two 500 mg capsules a day.
I think there is another supplement called PPQ, which may be even more effective than Berberine for glucose control. But I have not really looked into that any further.
Advantage of Berberine is no need for for a prescription and can order OTC online.