I have to take magnesium at night due to having restless leg syndrome. If I don't my legs get crampy and achy. Normally I take 3-4 magnesium glyconate tablets or I use magnesium citrate powder. Both are expensive and you must take quite a lot. I don't know what they magic forumla in these capsules are, but I only need 2 for a quiet night's sleep. I found them effective for nighttime leg issues with no stomach side effects that magnesium supplements can sometimes have.