AspartateNot recommended
ChlorideGooddetoxing, metabolism, kidney function
CitrateNot recommended. Contains ascorbic acid and magnesium carbonate. Known to destroy the enzyme function of ceruloplasmin. Ascorbic acid – damages ceruloplasmin.
GlycinateGoodRelaxing, Sleep, anxiety, nerve pain, serotonin production
MalateGoodContains malic acid. Aids in the formation of cellular energy (adenosine triphosphate or ATP) Energizing, muscle fatigue, muscle pain, fibromyalgia. Peaceful night sleep, optimal bone and dental health, strong and lean muscle development, stress reduction, boosted mood
OxidePoorLaxative, strong bones, healthy muscles, anxiety and migraines. Good in small doses throughout the day. When combined with water, it forms magnesium hydroxide. Milk of Magnesia has about 500 mg magnesium hydroxide per tablespoon! (**)
OrotateHighCardiovascular health and unconfirmed but recommended for athletic performance and endurance
SulfateGoodEpsoms salts! Best in the bath/body rub then shower! Relax tensed muscles and detoxify the body.
Taurate GoodCardiovascular health. Composed of both taurine and magnesium. Helps balance calcium and magnesium ions inside cells which helps to control heart function and blood pressure.
L.ThreonateGoodThis supplement can cross the brain barrier. Neuro conditions, anxiety, depression, PTSD, cognitive function & memory. Boosts brain function delays brain aging and is a sleep booster!
Dosage: The general rule is 10mg per 1kg of body weight.
** For Osteoporosis. 300-1800 mg of magnesium hydroxide taken daily for 6 months, followed by 600 mg of magnesium hydroxide taken daily for 18 months, has been used.

Large part of this table comes from the Magnesium Advocacy Group. With lots of interesting information, it is a place to search for sure!