For purposes of cellular detoxification and tissue purification, the most effective form of magnesium is magnesium chloride, which has a strong excretory effect on toxins and stagnant energies stuck in the tissues of the body, drawing them out through the pores of the skin. Chloride is required to produce a large quantity of gastric acid each day and is also needed to stimulate starch-digesting enzymes.
According to Daniel Reid, author of The Tao of Detox, magnesium sulfate, commonly known as Epsom salts, is rapidly excreted through the kidneys and therefore difficult to assimilate. This would explain in part why the effects from Epsom salt baths do not last long and why you need more magnesium sulfate in a bath than magnesium chloride to get similar results. Magnesium chloride is easily assimilated and metabolized in the human body.
In addition to its functions as an electrolyte, chloride combines with hydrogen in the stomach to make hydrochloric acid, a powerful digestive enzyme that is responsible for the breakdown of proteins, absorption of other metallic minerals, and activation of intrinsic factor, which in turn absorbs vitamin B12.
Using other magnesium salts is less advantageous because these have to be converted into chlorides in the body anyway. We may use magnesium as oxide or carbonate but then we need to produce additional hydrochloric acid to absorb them. Many aging individuals, especially with chronic diseases who desperately need more magnesium, cannot produce sufficient hydrochloric acid and thus cannot absorb the oxide or carbonate.
Chloride is a highly important and vital mineral required for both human and animal life. Without chloride, the human body would be unable to maintain fluids in blood vessels, conduct nerve transmissions, move muscles, or maintain proper kidney function. As a major electrolyte mineral of the body, chloride performs many roles, and is rapidly excreted from the body.
Magnesium chloride solution was not only harmless for tissues, but it had also a great effect over leucocytic activity and phagocytosis; so it was perfect for treatment of external wounds. – Dr. Jean Durlach
Dr. Jean Durlach et al., at the Université P. M. Curie, Paris, wrote a paper about the relative toxicities between magnesium sulfate and magnesium chloride. They write, “The reason for the toxicity of pharmacological doses of magnesium using the sulfate anion rather than the chloride anion may perhaps arise from the respective chemical structures of both the two magnesium salts. Chemically, both MgSO4 and MgCl2 are hexa-aqueous complexes. However MgCl2 crystals consist of dianions with magnesium coordinated to the six water molecules as a complex, [Mg(H2O)6]2+ and two independent chloride anions, Cl-. In MgSO4, a seventh water molecule is associated with the sulphate anion, [Mg(H2O)6]2 +[SO4. H2O]. Consequently, the more hydrated MgSO4 molecule may have chemical interactions with paracellular components rather than with cellular components, presumably potentiating toxic manifestations while reducing therapeutic effect.”
MgSO4 is not always the appropriate salt in clinical therapeutics. MgCl2 seems the better anion-cation association to be used in many clinical and pharmacological indications. -Dr. Jean Durlach et al.
Researchers studying the ionic fluxes in the two directions between the mother and the fetus found that there was a greater positive effect when MgCl2 was used and that MgSO4 could not guarantee the fetal needs in sodium and potassium exchange like MgCl2 could. They also found that MgCl2 interacts with all the exchangers in the cell membrane, while the effect of MgSO4 is limited to paracellular components without interaction with cellular components. Dr. Durlach summarized saying, “MgCl2 interacts with all exchangers while the interaction of MgSO4 is limited to paracellular exchangers, and MgCl2 increases the flux ratio between mother and fetus while MgSO4 decreases it.”
High-dosage, tocolytic magnesium sulfate (MgSO4) administered to pregnant women during preterm labor can be toxic and sometimes lethal for their newborns.
Chloride vs. Chlorine
The mineral supplement chloride is very different from the gas chlorine. Elemental chlorine is a dangerous gas that does not exist in the free elemental state in nature because of its reactivity, although it is widely distributed in combination with other elements. Chloride is related to chlorine however, as one of the most common chlorine compounds is common salt, NaCl. Chloride is a by-product of the reaction between chlorine and an electrolyte, such as potassium, magnesium, or sodium, which are essential for human metabolism. Chloride salts are essential for sustaining human metabolism and have none of the effects of isolated chlorine gas.
Magnesium Chloride, Bromide & Iodine
Dr. David Brownstein promotes the use of magnesium chloride as a supplement “synergistic” to treatment with iodine. Chloride competes with bromide at the renal level and increases the renal clearance of bromide, thus magnesium chloride is ideal for magnesium supplementation. Some patients require up to two years of iodine therapy to bring post loading urine bromide levels below 10 mg/24 hr, if chloride load is not included in the bromine detoxification program. Dr. Brownstein says, “As with using any nutritional supplement, a comprehensive holistic treatment plan provides the best results. Magnesium is an important part of the iodine treatment plan. Magnesium deficiency is very common. Magnesium is nature’s relaxing agent. Magnesium levels (via red blood cell magnesium levels) should be assessed and supplementation instituted. Magnesium supplementation will likely ensure optimal results with iodine.”
 Magnesium Research. Volume 18, Number 3, 187-92, September 2005, original article
 Mittendorf R, Dammann O, Lee KS. Brain lesions in newborns exposed to high-dose magnesium sulfate during preterm labor. Department of Obstetrics and Gynecology, Loyola University Medical Center, Maywood, IL, USA.J Perinatol.2005 Dec 1; doi:10.1038/sj.jp.7211419.
 Rauws, A.G., Pharmacokinetics of Bromide Ion-An Overview. Fd. Chem. Toxic., 21:379-382, 1983
 Iodine, the Rest of the Story; David Brownstein M.D.;