Nutricost's Magnesium Bisglycinate contains 210mg of magnesium per serving. Each bottle contains 250 grams of magnesium bisglycinate. Nutricost, located and headquartered in the USA, only uses the best ingredients to ensure maximum quality and to help you feel your best! By keeping our supplement recipes simple and clean, you get the best experience possible with Nutricost. Our supplements are manufactured in a GMP-compliant and FDA-registered facility; and each batch of every product is tested by independent, ISO-accredited laboratories.