BEST SELLER! The main role of magnesium in the body is to work with calcium in muscle and nerve function. Calcium causes muscles to contract, magnesium causes them to relax again. Calcium causes nerves to fire, magnesium calms them back down. Our Amino Acid Chelate form of magnesium is the most highly absorbable form of magnesium available. Your body needs many amino acids for regeneration and repair of every tissue in your body, so there are lots of absorbtion sites for amino acids in the intestinal lining. When your magnesium is bound to amino acids, that means many more chances for it's absorbtion. This product is also a low dose, about 133mg per tablet, which means you can take it several times a day without getting the laxative effect that comes at larger doses. Great for muscle cramps, relaxing the nerves and a better night's sleep.