Over the counter magnesium supplements are available in a variety of salt forms including:

  • Magnesium oxide
  • Magnesium citrate
  • Magnesium L-aspartate
  • Magnesium chloride
  • Magnesium gluconate

Magnesium supplements should generally be taken with food to allow for maximum absorption. While they can be taken on an empty stomach, food generally increases the extent of absorption of magnesium products.

It is important to note that all of the different forms of magnesium contain different percentages of elemental magnesium. For example, magnesium oxide contains 60% elemental magnesium by weight while magnesium chloride contains only 12% elemental magnesium by weight.