How to Choose a Magnesium Supplement

By Thomas E. Levy, MD

There are many different forms and routes of magnesium supplementation. How to choose a magnesium supplement depends on the needs of the patient, along with considerations of expense and convenience. 

Magnesium has many different chemical forms, and it has been administered intravenously, intramuscularly, orally, transdermally, via enema, and via inhalation by nebulization. 

Keep reading to learn the difference between magnesium supplements and delivery methods. 

Forms of Magnesium

Magnesium Citrate

This common and inexpensive form of magnesium is often used in large doses to deliberately induce a cleansing, watery diarrhea to prepare for a major surgery or colonoscopy. 

Magnesium Sulfate 

You may know this form of magnesium as Epsom salt. Although not the optimal form for oral supplementation (as it readily results in a diarrhea or loosening of the stools as seen with magnesium citrate), magnesium sulfate is the most common form of magnesium given intravenously.  Taking Epsom salt baths appears to offer much of the known benefits of magnesium administration, as significant amounts of magnesium can be assimilated transdermally from this practice. 

Magnesium Taurate 

This bioavailable form of magnesium is complexed with taurine, an important sulfur-containing amino acid.  Taurine is known to have antioxidant and anti-inflammatory properties. It is the most plentiful amino acid in the body, and it plays an important role in supporting normal physiology, especially beneficial in supporting good cardiac, brain, and eye health. Relative to other forms of magnesium, it does not readily result in diarrhea at lower doses.

Magnesium Gluconate 

The gluconate form of magnesium is an organic salt that has a high degree of absorption. In a study on magnesium-depleted rats, this form of magnesium was absorbed and retained better than nine other forms of magnesium that were studied (oxide, chloride, sulfate, carbonate, acetate, pidolate, citrate, lactate, and aspartate). 

Magnesium Chloride 

This form of magnesium is inexpensive and absorbed very well relative to the other oral forms of magnesium.  

Magnesium Glycinate 

This form of magnesium is bound to an amino acid, glycine. This magnesium supplement is more bioavailable and absorbable than many of the other forms of oral magnesium, and less likely to cause the diarrhea effect. While not one of the essential amino acids that must be supplied by diet or supplementation, glycine is one of the three amino acids needed for the body to synthesize glutathione, an antioxidant especially critical for maintaining a normal intracellular level of oxidative stress. Glycine is also essential for the synthesis of creatine and collagen in the body. Additional sources of glycine in supplementation and the diet are always good practices. 

Magnesium Oxide 

This form of magnesium is especially inexpensive, and it is probably the most common form of magnesium supplementation sold in pharmacies and supplement stores. While it has one of the poorest absorption rates, the literature has nevertheless documented many clear-cut benefits from its administration, often in doses of 500 mg daily.

Magnesium Aspartate and Magnesium Glutamate 

While aspartate and glutamate are not toxic per se, they are probably both best avoided for relatively high dosing on a regular basis, especially in light of the many other forms of magnesium with clearly beneficial anions that can be supplemented. 

Magnesium Carbonate 

This form of magnesium effectively becomes magnesium chloride after mixing with the acid in the stomach (and also forming carbon dioxide and water). Additionally, it has significant antacid properties. 

Magnesium L-Threonate 

This is the only form of magnesium scientifically shown to raise magnesium levels in the brain where it supports relaxation and cognitive health.

Types of Magnesium Supplements

Pills, powders, and gummies

A large number of different magnesium supplements can be taken from traditional forms, including capsules, pills, powders, and gummies. While they all can deliver beneficial amounts of magnesium depending on the doses taken, the efficiency of absorption, the unique contributions of the associated anion that is hooked to the magnesium (cation), and the degree of side effects, like loosened stools or diarrhea, can vary widely. Because of all these factors, the costs of different magnesium supplements can also vary widely. The most common forms are inexpensive, as supplements go in general. However, most of these forms of magnesium supplements offer poor absorption.

Liposomal Magnesium Supplements

Vitamins, minerals, and other nutrient agents are becoming increasingly available in oral liposome-encapsulated forms. Liposomes are fat-based spheres that surround magnesium to protect it through the digestive system into the bloodstream. Because liposomes are made of the same material that makes up your cells, they can sidle up to the cell and deliver the magnesium into the cell where it performs 99% of its vital work.

When the liposome formulation is a quality product, the encapsulated agents can enter the bloodstream and absorb in the cells typically without the consumption of energy, amazingly enough. It must be pointed out, however, that there is a great deal of fraud among supplements that are now labeled as being encapsulated in liposomes. 

Many agents not liposome-encapsulated yet given intravenously still need to consume energy via active transport to end up inside the cells. While the mechanisms for magnesium cellular uptake remain to be fully elucidated, the normally extremely high intracellular magnesium concentrations relative to extracellular concentrations logically demands that an energy-consuming active transport process must be involved to further concentrate magnesium inside cells. 

Intravenous Magnesium

The intravenous administration of magnesium is the most common form given in the hospital and clinic setting. Intravenous magnesium is a safe way to administer magnesium, and it has a wide margin of safety. However, unlike many other nutrient supplements, magnesium can be overdone and cannot be given with the abandon of something like the virtually nontoxic vitamin C. 

It would also appear that a substantial amount of intravenous magnesium is ultimately retained inside the cells of the body. Studies on patients who received high doses of magnesium sulfate intravenously demonstrated a profoundly positive longevity effect after the one-time hospital dosing. The patients in one study received 22 grams of magnesium over 48 hours. All-cause mortality was significantly decreased over as long as 5 years post-infusion. 

Intramuscular Magnesium

It appears that the intramuscular administration of magnesium disseminates throughout the body well, as patients given IM injections showed good uptake of magnesium into the brain. 

Transdermal Magnesium

Transdermal delivery of an agent simply means a form of administration that goes into and ultimately through the skin. Depending on the nature of the components being used in the transdermal application or delivery system (e.g., patch), substantial amounts of the agent being dosed can enter the systemic circulation, so they reach areas away from the application site. 

Magnesium can be reliably introduced into the body via transdermal delivery. However, the degree and consistency of delivery from one application to the next remains in doubt.  One study showed that the application of magnesium cream resulted in a rise in both serum and urinary magnesium markers. 

Transdermal magnesium avoids the gastrointestinal side effects seen with regular oral forms of magnesium supplementation. This form of magnesium is a good adjunct in helping to support the magnesium levels resulting from its other more common forms of administration. Its regular use is also one good way to support skin health. The typical forms of magnesium for transdermal use are as an oil, a gel, a lotion, or as bath salts. Magnesium oil is a concentrated solution of magnesium chloride and water. A gel or lotion is less concentrated and mixed with any of a number of different agents commonly used for skin or cosmetic applications. The bath salts are generally magnesium chloride flakes or granular magnesium sulfate (Epsom salt). 

An additional “form” of transdermal magnesium application comes in the form of a magnesium-containing enema. The mucosal lining throughout the gastrointestinal tract is very effective in absorbing just about any agent with which it comes in contact for a long enough period of time. Applications of magnesium via enema are especially useful when oral intake is impaired or limited, and when intravenous infusions are not readily available or economically feasible. However, the amount of rectal absorption of magnesium can be difficult to predict and toxicity can occur even in the face of normal renal function. 

Magnesium Nebulization

Nebulization is the process that effectively converts a medicament from a liquid form into a fine mist that can be readily inhaled into the upper respiratory tract and the lungs.  The administration of a drug or nutrient agent via such a route of inhalation has an extensive history, actually dating back more than 3,500 years ago to ancient Egypt.  

Nebulization offers multiple benefits, including the following:

• Moistens the inhaled air, helping to thin secretions and mucus and allowing them to be mobilized and expelled
• Lessens the need to cough as more secretions and mucus end up getting eliminated
• Allows the direct inhalation of bronchodilating therapeutic agents
• Allows the direct inhalation of agents that can combat pathogens colonizing and/or grossly infecting the upper respiratory tract and lungs
• Permits the use of lower amounts of therapeutic agents that would be more prone to toxicity when given systemically in much higher doses, either orally or intravenously
• Permits some systemic assimilation of the nebulized agent throughout the body

Nebulization dosing and administration protocols should be worked out with a physician or other chosen health care provider. Generally, any nebulization should be comfortable and any odor should not be overly pungent or off-putting. However, it should be discontinued if any coughing or even minimal compromise of breathing results. Often, when not well-tolerated, it can be continued subsequent to greater dilution of the nebulized agents.

Which magnesium supplement is best?

The best magnesium supplement varies depending on your reasons for taking it. The most effective magnesium supplement for ongoing health is the one your body can absorb. If it doesn’t absorb, a magnesium supplement isn’t doing much (unless, of course, you are using it to induce loose stools, in which case you want a low-absorption supplement). 

It is extremely important to get magnesium inside your cells because that’s where it does 99% of its life-sustaining work. Of all the forms of magnesium supplements mentioned in this article, the liposomes alone offer a means of absorbing magnesium inside the cell without using energy.

Thomas E. Levy, MD, JD is a board-certified cardiologist and the author of Primal Panacea and Curing the Incurable: Vitamin C, Infectious Diseases, and Toxins; plus three other groundbreaking medical books. He is one of the world's leading vitamin C experts and frequently lectures to medical professionals all over the globe about the proper role of vitamin C and antioxidants in the treatment of a host of medical conditions and diseases.