I've found that the form of magnesium is more important than the brand... I've used Source Natural Magnesium Malate for a long time, which helps w pain (due to the mag being bound to malic acid)...
Next, I want to try the Mag Glycinate and Mag Lysine, which have immune/anti-viral effects.
my notes below
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FORMS OF MAGNESIUM: All magnesium is mined as minerals from the earth. However, the mineral is bonded or chelated to various organic or inorganic substances to increase absorption and bioavailability. Different forms of magnesium have varying levels of magnesium concentration.
* Organic forms: glycinate, bisglycinate, lysinate, citrate, malate, aspartate, gluconate, threonate, and lactate.
* Inorganic forms: oxide, sulfate, chloride, hydroxide, and carbonate.
Generally, the organic forms are much better absorbed and better tolerated by the gut because they increase the body's ability to recognize and absorb the mineral. Inorganic forms are cheaper, not as well absorbed, and act as laxatives, but have higher magnesium concentration.
* Magnesium Oxide. This is the most common and cheapest form of magnesium. This form contains a very high level of elemental magnesium, so you can fit 100% of your daily value of magnesium (400 mgs) into one pill. However, there is evidence that very little of this form is absorbed and taking more than one or two pills can cause a laxative effect. Magnesium oxide is possibly the worst form of magnesium and is not recommended.
* Magnesium Citrate. This is the second most common form of magnesium. It is certainly better absorbed than magnesium oxide, but it can also cause a laxative effect if taken in higher doses. High levels can draw water into the bowels resulting in loose stools.
* Magnesium Glycinate and Bisglycinate. Glycinate has one glycine bound to magnesium while bisglycinate has two glycine molecules. These are probably the best forms, with bisglycinate providing more glycine for added absorption and additional relaxation and detoxification benefits. There is no laxative effect. The disadvantage here is that these forms have low magnesium concentration, requiring higher number of pills per day.
* Magnesium Lactate. Moderately well absorbed and has been shown to provide benefits for stress. Some people are allergic to it. This form needs more research.
* Magnesium Malate. Very well absorbed with no laxative effects. It has been shown to help people who suffer from fatigue. Helps balance stomach acid, as well.
* Magnesium Gluconate. Moderately well absorbed with little or no laxative effects.
* Magnesium Aspartate. Moderately well absorbed but aspartate is best avoided in high doses as excess aspartic acid can negatively affect nerves.
* Magnesium Threonate. Very well absorbed. This new form has been shown to cross the blood-brain barrier to provide magnesium benefits to the brain. Other forms of magnesium may also provide the same benefits to the brain, but threonate is the only one with some proof. Needs more human clinical studies, which are in progress. This form has a very low magnesium concentration, so you will have to take many pills to get 100% of your daily value.
* Magnesium Lysinate. A well absorbed source of magnesium without laxative effects. The amino acid lysine is an excellent anti-viral.