I recently got some Nutra Science 500mg 98% purity berberine capsules from Amazon. You have to be very careful where you buy it as some of brands have little or no berberine in them and the best have nearly 100% purity. See this comparison on some US berberine brands ...
As a result of watching that video I ordered some
Natural Factors Berberine from iHerb.com. It seems to take a couple of weeks to arrive in the UK.
The benefits of berberine are described in this video ...
It is supposed to help lower blood sugars and help lower insulin resistance and reduce inflammation. It works similar to metformin by reducing gluconeogenesis in the liver. My morning fasting blood glucose was over 8.0 last May, but now it is averages about 5.7. On my Dexcom One+ CGM my average blood glucose is now 6.3 and my GMI (estimated HbA1C) has reduced from 6.5 in June to 6.0 now.
I started to notice significant lowering of fasting blood sugars after taking 2x300mg of benfotiamine every day, down from about 7.0 on June 23 to around 5.7 now. I also started taking 240mg of r-Alpha Lipoic Acid on 19 Jul and 500mg berberine on 2 Aug. I take the berberine 1/2hr before eating to help lower the glucose spike. My CGM average blood glucose level has dropped since taking berberine. I might try 2x500mg once I get the Natural Factors WellbetX beberine as that brand is is best seller in the USA and has a very high approval rating and known purity.
Some people also use berberine as an aid to help loose weight. It has helped me a little. I have also noticed some greater mental clarity.
I have seen some warnings that you should not take high doses of berberine for more than 3 months and you need to be careful if you take blood pressure medication as berberine also reduces high blood pressure.