Magnesium Supplementation Quiz There are many oral forms of magnesium for horses available on the market. MagRestore contains a highly bio-available form of magnesium that has the least potential laxative effect. Do you know what type of magnesium we use? Do you know what type of magnesium is used in Performance Equine Nutrition's MagRestore? Magnesium Oxide Di-magnesium Malate Magnesium Citrate Magnesium Sulfate Not quite. Many other companies use magnesium citrate, but we use a form of magnesium that you may find even more effective. Would you like to try again?You're right! Di-magnesium malate is highly absorb-able, bio-available and has the least potential laxative effect.Read more about MagRestoreNot quite. Horse owners should avoid magnesium sulfate because of its laxative effect.Would you like to try again?No, magnesium oxide is great for cows, but not for horses. Would you like to try again?Email Δ