Posted by iHerb Customer on Jul 25, 2008 | Verified Purchase
I switched to this after being on Mg oxide 500 mg. I can tell there is a huge difference in amount absorbed with this product having 400 mg (100 less). My neck and back pains have significantly decreased and am hoping it will prevent any more kidney stones from forming. The only thing I don't like about this product is the size of the tablet is huge and hard to choke down. I am now just crushing it up instead.