Magnesium Chloride: Benefits, Oil Uses, Dosage & Side Effects

Dr. Josh Axe Vitamin Advisor · 4–5 questions

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Magnesium chloride is magnesium in one of its simplest forms: the mineral paired with chloride, the same partner sodium has in table salt. It forms in nature as the mineral bischofite, and it's a major part of bittern, the liquid left over when salt is extracted from seawater, which has been used for a long time to set tofu.89 The crystals are so drawn to water that they pull moisture out of the air, and that same pull lets the salt dissolve completely in a glass.81

You can take it by mouth as tablets, capsules or a liquid, or use it on your skin as bath flakes or as the sprays sold as magnesium oil. The sprays tested in the skin studies on this page were magnesium chloride dissolved in water.101112

Your body puts magnesium to work in the enzyme systems that control blood sugar and blood pressure, along with muscle and nerve function.1 In a 2026 episode of my show, I pointed out that 48% of Americans aren't getting enough magnesium; that's the share of the U.S. population that ate less than the requirement from food in national survey data from 2005 and 2006.613

My approach to magnesium starts with food, leafy greens first and then nuts, seeds and legumes. From there, I test rather than guess, and when a supplement makes sense, I match the form to the goal.146 I put magnesium alongside vitamin D and omega-3s as the most essential things to take regularly.14 Magnesium chloride is one of the forms your body absorbs best, and it's the form behind a long run of trials on blood pressure, blood sugar and mood.12

Did you know?

• Your water can be a magnesium source: tap, mineral and bottled waters carry anywhere from 1 mg to more than 120 mg of magnesium per liter, depending on the source.1

• The FDA recognizes magnesium chloride as safe as a direct food ingredient, used for flavor and as a nutrient, and it's permitted in infant formula.8

• An adult body holds about 25 grams of magnesium, with 50% to 60% of it in the bones and most of the rest in soft tissues.1

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What is magnesium chloride?

Magnesium chloride, magnesium chloride hexahydrate and MgCl2 name the same compound, with or without the water bound into its crystals. The dry (anhydrous) salt is about 25% magnesium by weight and the hexahydrate about 12%, figures that come straight from their molecular weights.1516 That's why a good-sized tablet can carry a modest dose: in a University of Vermont trial, each 500 mg magnesium chloride tablet supplied 62 mg of magnesium.5 The Supplement Facts panel lists that elemental magnesium, the amount of the mineral itself, rather than the weight of the whole compound, so it's the number to read.1

It comes in four main forms:

• Tablets and capsules: The form used in the Vermont mood trial, and as slow-release tablets in trials on blood pressure and fibromyalgia.51718
• Liquid: Magnesium chloride dissolved in water, the form used in the placebo-controlled trials on blood pressure and blood sugar.34
• Sprays: A concentrated solution, sold as magnesium oil, that you rub into the skin; it was tested for cramps, fibromyalgia and nerve symptoms.101112
• Flakes: Crystals you dissolve in a bath or a foot soak.

Magnesium chloride is one of several types of magnesium, and the form comparison below shows how it lines up with the others.

A short history of magnesium chloride

Long before it came in capsules, magnesium chloride came from the sea. Bittern, called nigari in Japan, is rich in magnesium chloride and has long served as the main ingredient in tofu coagulants, the ingredient that turns soymilk into curds.919 Bathing in magnesium-rich water is also one of the oldest therapies for skin conditions, from soaks in the Dead Sea, where magnesium salts are the most plentiful minerals, to Epsom salt baths.2021

What is magnesium chloride good for?

How does magnesium chloride work in your body?

Magnesium chloride hands your body magnesium in a form that's ready to absorb, and from there the mineral goes to work inside your cells.

Magnesium chloride benefits, ranked by evidence

Ordered by how much human research backs each one, magnesium chloride's benefits start with raising low magnesium and lowering blood pressure, followed by blood sugar and mood, with early evidence for inflammation, sore muscles and skin and heart rhythm in heart failure.

Does magnesium chloride lower blood pressure?

In my High Blood Pressure Protocol, low magnesium and potassium are one of the eight root drivers of high blood pressure, because these minerals relax vessel walls and balance sodium.7 The protocol's supplement page puts it this way: "Magnesium is the flagship: the mineral your vessels relax on."7 The form and amount are in the dosing section below.

A placebo-controlled trial in Durango, Mexico, tested magnesium chloride itself. Researchers gave 82 adults aged 40 to 75, all with diabetes, high blood pressure and low blood magnesium and all taking the blood-pressure drug captopril, either 2.5 grams of magnesium chloride a day in solution or a placebo for 4 months; neither the people nor the researchers knew who got what. Among the 79 who finished, systolic pressure fell 20.4 points, against 4.7 on placebo, diastolic pressure fell 8.7 points against 1.2, and HDL cholesterol rose slightly.3

A 2025 pooled analysis in the journal Hypertension gathered 38 randomized trials with 2,709 people taking magnesium in several forms for at least 4 weeks, at a median of 365 mg a day for a median of 12 weeks. Overall, systolic pressure fell 2.81 points and diastolic pressure 2.05 points more than on placebo. The drops were larger in people with low magnesium (5.97 systolic and 4.75 diastolic) and in people with high blood pressure who were already taking medication (7.68 systolic), while in people with normal blood pressure the change wasn't significant. The 7 magnesium chloride trials lowered systolic pressure by 6.28 points and diastolic pressure by 5.01; every one of them enrolled people with low magnesium, so the authors note that result may reflect correcting a shortfall.22

An independent trial pointed the same way. At East Carolina University, 28 adults with type 2 diabetes and high cholesterol each took slow-release magnesium chloride tablets (384 mg of magnesium a day) and a placebo for 6 weeks apiece, with neither they nor the researchers knowing which was which, and systolic pressure fell 7.4 points on magnesium, while diastolic pressure, blood sugar, cholesterol and blood magnesium didn't change significantly.17

Magnesium fits inside a high blood pressure diet built on mineral-rich foods, with potassium-rich foods right beside it.7 If you take blood-pressure medicine, read the medication note in the safety section below before you start.

Does magnesium chloride help blood sugar?

Magnesium and blood sugar affect each other. Your body uses magnesium in the enzymes that control blood sugar, and people with insulin resistance or type 2 diabetes lose more magnesium in their urine, because higher glucose in the kidneys increases urine output.1 Low magnesium in turn reduces insulin sensitivity, so a blood-sugar problem and a magnesium shortfall can feed each other.23

My position is that type 2 diabetes can be reversed in many cases with diet, exercise and lifestyle, supported by natural remedies like berberine, chromium, cinnamon and magnesium. Diet and lifestyle do the heavy lifting: in the DiRECT trial in Scotland and England, 46% of 149 adults with type 2 diabetes in a structured diet and weight-loss program were in remission at 12 months, against 4% of 149 on usual care, with everyone knowing which program they were in.32 Magnesium is the support: a dose-response analysis of 18 randomized trials in type 2 diabetes estimated that magnesium at 500 mg a day lowers HbA1c by 0.73 percentage points.33

The Durango group also tested magnesium chloride for blood sugar. In a placebo-controlled trial of 63 adults with type 2 diabetes and low magnesium, all taking the diabetes drug glibenclamide, 50 mL of magnesium chloride solution a day (2.5 grams) for 16 weeks left insulin resistance (HOMA-IR) at 3.8 against 5.0 on placebo, fasting blood sugar at 8.0 against 10.3 mmol/L (about 144 against 186 mg/dL) and HbA1c at 8.0% against 10.1%.28

In a placebo-controlled trial of adults without diabetes who had insulin resistance and low magnesium, 2.5 grams a day for 3 months cut HOMA-IR from 4.6 to 2.6, while the placebo group went from 5.2 to 5.3.23 In a placebo-controlled trial of 106 adults without diabetes and with low magnesium, 3 months of magnesium chloride also improved how well the insulin-making cells of the pancreas kept up with the body's needs.34

The prediabetes trial gave 116 adults aged 30 to 65 either 30 mL of a 5% magnesium chloride solution a day or an inert placebo for 4 months; neither the people nor the researchers knew who got what. By the end, 50.8% of the magnesium group improved their blood-sugar status, against 7.0% on placebo. Fasting blood sugar was 86.9 against 98.3 mg/dL, blood sugar 2 hours after a glucose drink was 124.7 against 136.7 mg/dL, HOMA-IR was 2.85 against 4.1, and triglycerides were 166.4 against 227.0 mg/dL.4

The same group tested metabolic syndrome, the cluster of high blood pressure, high blood sugar, high triglycerides, low HDL and extra belly fat. In a placebo-controlled trial of 198 adults with metabolic syndrome and low magnesium, 30 mL of a 5% magnesium chloride solution a day for 16 weeks brought down blood pressure, fasting blood sugar and triglycerides more than placebo, and at the end 48% of the magnesium group still had metabolic syndrome, against 77.5% on placebo.35

An independent randomized trial in Saudi Arabia tested magnesium chloride in drinking water. Of 230 adults with type 2 diabetes who weren't low in magnesium, 102 finished 3 months of bottled water with 0, 20 or 50 mg of magnesium per liter, without knowing which they had. At 50 mg per liter, HbA1c, fasting blood sugar and cholesterol didn't improve more than with plain water, but insulin resistance (HOMA-IR) fell from 2.9 to 2.5 and blood insulin from 9.9 to 7.5 µIU/mL, both significantly more than with plain water.26

For the full food and lifestyle plan, see the insulin resistance diet and my free Insulin Resistance & Prediabetes and Type 2 Diabetes protocols. If you take medicine for blood sugar, read the medication note in the safety section below before you start.

Does magnesium oil work?

For sore muscles, I like a warm soak with Epsom salt or a magnesium spray rubbed into the area; both are magnesium salts, and both are good for helping muscles relax.6 As I put it in a 2016 video, "Magnesium is known as the relaxation mineral. So if you have an area of muscle spasm or tension, magnesium helps calm and relax the area."36 Epsom salt is magnesium sulfate, while the sprays in the studies below are magnesium chloride.101112

Here's what the studies in people found:

• Cramps: In 7 adults with an ileostomy and chronically low magnesium (6 finished), 10 sprays of magnesium chloride twice a day, about 150 mg of magnesium, for 6 weeks raised blood magnesium in 2 people (by 0.27 and 0.13 mmol/L), spared 1 a planned magnesium infusion, and no one's level fell by more than 0.07 mmol/L. All 6 had muscle cramps at the start, and 5 reported improvement or complete relief by week 3. There was no comparison group, and the spray's maker paid for the study and supplied the spray.10
• Fibromyalgia: At the Mayo Clinic, 40 women with fibromyalgia used 4 sprays of magnesium chloride on each arm and leg twice a day for 4 weeks, and among the 24 who finished, scores on a standard fibromyalgia questionnaire improved at weeks 2 and 4, with no comparison group.11
• Nerve symptoms: In 20 older adults with advanced kidney disease and neuropathy (14 finished), 5 sprays on each affected limb daily for 12 weeks lowered a neuropathy symptom score from 6.92 to 4.26, while blood magnesium didn't change significantly; there was no comparison group.12
• Skin: In 30 adults with dry, atopic skin, soaking one forearm for 15 minutes a day in a 5% solution of Dead Sea salt rich in magnesium chloride, with the other forearm in tap water, improved skin hydration and reduced roughness and redness over 6 weeks, and improved the skin barrier in the people whose barrier was weakest at the start. Co-authors came from a dermatology consultancy and the salt's maker.21

How much magnesium passes through intact skin is still being worked out. In lab studies of human skin, magnesium crossed the outer layer, more with higher concentrations and longer contact, and hair follicles carried a good share of it.20 In pig skin, intact skin let through very little magnesium from a magnesium sulfate solution, not significantly more than skin left untreated, while skin with its outer layer stripped away let through far more.37

In people, a magnesium cream supplying 56 mg a day for 2 weeks raised blood magnesium from 0.82 to 0.89 mmol/L, against 0.77 to 0.79 on a placebo cream in a pilot of 25 adults, a difference that reached significance only among the non-athletes.38 After a hard downhill run, 35 active adults who rubbed a magnesium gel on their thighs had the same soreness, strength and muscle-damage markers as those using a placebo gel; neither the people nor the researchers knew who got what, and the authors note the gel's dose may have been too low.39 To correct a measured low level, the blood-pressure and blood-sugar trials on this page used magnesium by mouth.34

To use it the way these studies did, spray it onto your arms, legs or torso once or twice a day, or soak in a solution of magnesium-rich salt. I'm a big fan of a warm Epsom salt bath, soaking for about 20 minutes, to take the edge off stress.6 Flakes and sprays are for your skin only, and the safety section below explains why. For more ways to recover after a hard workout, see our guide to muscle recovery.

Which foods are high in magnesium?

Pumpkin seeds, chia seeds, almonds, spinach, cashews and black beans are among the richest everyday sources: an ounce of roasted pumpkin seeds has 156 mg of magnesium, 37% of the daily value.1 My High Blood Pressure Protocol's Remineralize step adds a magnesium-rich food to every meal.7 In that protocol, spinach, arugula and Swiss chard lead the list because they deliver dietary nitrate plus magnesium and potassium, the trio that relaxes and widens arteries.7

Values from the NIH Office of Dietary Supplements, based on USDA FoodData Central; the daily value for magnesium is 420 mg.1

An ounce of pumpkin seeds, a half cup of cooked spinach and a half cup of black beans add up to 294 mg of magnesium. Food processing works against you here: refining grains removes the germ and bran, and with them much of the magnesium.1 For more ideas, see our full list of foods high in magnesium.

How do you know if your magnesium is low?

A standard blood test can miss it. Less than 1% of your body's magnesium is in blood serum, and serum levels don't accurately reflect what's in your tissues.1 A normal serum magnesium doesn't mean you're fine, so I prefer the red blood cell (RBC) magnesium test, which looks at the magnesium inside your cells.6 Test, don't guess.

Early signs of low magnesium include loss of appetite, nausea, fatigue and weakness, and as a shortfall deepens, numbness, tingling, muscle cramps and abnormal heart rhythms can follow.1 Some people are more likely to run low:1

• Type 2 diabetes or insulin resistance: Higher blood sugar raises urine output, and more magnesium leaves with it.1

• Older adults: Absorption from the gut falls and losses through the kidneys rise with age.1

• Long-term diuretics or acid blockers: Loop and thiazide diuretics increase the magnesium lost in urine, and proton pump inhibitors taken for more than a year can lower magnesium.1

• Digestive conditions: Chronic diarrhea and poor fat absorption in Crohn's disease and celiac disease can drain magnesium over time, and a high-output ileostomy often brings low magnesium with it.110

• Heavy alcohol use: Magnesium deficiency is common with chronic alcohol dependence.1

Magnesium chloride vs. glycinate, citrate and Epsom salt

Absorption is where magnesium chloride stands out. Forms of magnesium that dissolve well in liquid are absorbed more completely, and the NIH lists chloride with aspartate, citrate and lactate as forms with higher bioavailability than oxide and sulfate.1 In healthy volunteers, magnesium chloride was absorbed as well as magnesium lactate and aspartate and significantly better than magnesium oxide, whose fractional absorption was 4%.2 A 2025 review of absorption trials in healthy adults also rated chloride and citrate as having good bioavailability.40

Here's how the common forms line up:

For a soak, magnesium chloride flakes and Epsom salt both deliver a magnesium salt in warm water, so choose the one you enjoy. Our guide to magnesium supplements covers what to look for on the label, and our guide to magnesium for sleep goes deeper on rest.

How much magnesium chloride should you take?

The Recommended Dietary Allowance is 400 mg a day for men 19 to 30 and 420 mg from 31 on, and 310 mg and 320 mg for women in the same age groups.1 Healthy kidneys clear extra magnesium from food, which is why the 350 mg upper limit applies only to supplements and medicines.1

The blood-pressure and blood-sugar trials in Durango gave 1.5 to 2.5 grams of magnesium chloride a day in water, which the researchers reported as 382 to 450 mg of magnesium.34

In my High Blood Pressure Protocol, the flagship supplement is magnesium glycinate at 300 to 400 mg in the evening.7 In Heal Your Cells, Dr. Will Cole and I list magnesium glycinate or chelate at 300 to 400 mg a day of elemental magnesium, best taken in divided doses or at night for sleep support.42 Whichever form you choose, a few habits help:

1. Read the elemental line: The Supplement Facts panel lists elemental magnesium; that's the number to add up, along with any magnesium in a multivitamin.1

2. Give it time: Mood scores improved within 2 weeks in the Vermont trial, where each person tried both, while the placebo-controlled blood-pressure and blood-sugar trials ran 3 to 4 months.534

Magnesium chloride side effects and who should be careful

• Kidney disease. Healthy kidneys clear extra magnesium, but when kidney function is impaired, the risk of magnesium building up to toxic levels rises.1 Toxicity can bring low blood pressure, nausea, flushing, muscle weakness, trouble breathing and an irregular heartbeat.1 My High Blood Pressure Protocol says it plainly: with kidney disease, clear supplements with your prescriber first.7

• Medicines for blood pressure or blood sugar. Magnesium chloride lowered both in trials, so if you take medicine for either, your prescriber adjusts the dose as your numbers improve. Don't stop a prescribed medicine on your own.34

• Loose stools. Chloride is one of the forms of magnesium most often reported to cause diarrhea, along with carbonate, gluconate and oxide.1 Stay within the 350 mg supplement limit unless a practitioner is guiding a higher amount, and cut back if your stools loosen.

• Don't drink concentrated brine. Bath flakes, magnesium oil and liquid bittern are concentrates for the skin or the tofu pot. In one documented case, a 73-year-old woman who drank an unknown amount of bittern developed dangerously high blood magnesium and heart-rhythm changes on her ECG, and she recovered with fluids and calcium in the hospital.9

• Pregnancy and nursing. Adults need 350 to 360 mg of magnesium a day in pregnancy and 310 to 320 mg while nursing, and food is the place to start; if you take a magnesium supplement while pregnant or nursing, confirm the dose with your OB.1

• Children. Supplement limits are lower for children: 65 mg a day at ages 1 to 3, 110 mg at ages 4 to 8 and 350 mg from age 9, so a child's dose comes from their practitioner.1

The bottom line

Magnesium chloride: frequently asked questions

References

1. Office of Dietary Supplements, National Institutes of Health. Magnesium: Fact Sheet for Health Professionals. Updated January 6, 2026.
2. Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001;14(4):257-62. PMID:11794633
3. Guerrero-Romero F, Rodríguez-Morán M. The effect of lowering blood pressure by magnesium supplementation in diabetic hypertensive adults with low serum magnesium levels: a randomized, double-blind, placebo-controlled clinical trial. J Hum Hypertens. 2009;23(4):245-51. doi:10.1038/jhh.2008.129. PMID:19020533
4. Guerrero-Romero F, Simental-Mendía LE, Hernández-Ronquillo G, et al. Oral magnesium supplementation improves glycaemic status in subjects with prediabetes and hypomagnesaemia: A double-blind placebo-controlled randomized trial. Diabetes Metab. 2015;41(3):202-7. doi:10.1016/j.diabet.2015.03.010. PMID:25937055
5. Tarleton EK, Littenberg B, MacLean CD, et al. Role of magnesium supplementation in the treatment of depression: A randomized clinical trial. PLoS One. 2017;12(6):e0180067. doi:10.1371/journal.pone.0180067. PMID:28654669
6. Axe J. The #1 Mineral for Sleep That 48% of People Lack. The Dr. Josh Axe Show; February 16, 2026. Video J1vB4UTuW6I at 0:57–1:13 (mineral scarcity), 11:11–11:23 (magnesium and ATP), 12:20–12:28 (RBC magnesium), about 16:36 (glycinate for sleep and anxiety), 18:59–19:29 (Epsom salt and magnesium sprays for muscle relaxation) and 34:03–34:23 (Epsom salt bath).
7. Axe J. The High Blood Pressure Protocol. DrAxe.com; 2026. p. 7, "Root Causes: The Eight Drivers" (driver 2, magnesium and potassium); p. 11, "Step 2 · Remineralize"; p. 17, "Supplements" (magnesium glycinate, flagship; kidney-disease caution); leafy greens (spinach, arugula and Swiss chard).
8. U.S. Food and Drug Administration. 21 CFR 184.1426 Magnesium chloride (direct food substance affirmed as generally recognized as safe). Electronic Code of Federal Regulations.
9. Jung HM, Paik JH, Kim JH, et al. A case report of bittern intoxication. J Emerg Trauma Shock. 2015;8(2):108-9. doi:10.4103/0974-2700.145426. PMID:25949041
10. Nightingale J, Bakir IA, Adaba F. Pilot study of a topical magnesium preparation to treat hypomagnesaemia in patients with an ileostomy. Intest Fail. 2024;2:100018. doi:10.1016/j.intf.2024.100018. PMID:41648083
11. Engen DJ, McAllister SJ, Whipple MO, et al. Effects of transdermal magnesium chloride on quality of life for patients with fibromyalgia: a feasibility study. J Integr Med. 2015;13(5):306-13. doi:10.1016/S2095-4964(15)60195-9. PMID:26343101
12. Athavale A, Miles N, Pais R, et al. Transdermal Magnesium for the Treatment of Peripheral Neuropathy in Chronic Kidney Disease: A Single-Arm, Open-Label Pilot Study. J Palliat Med. 2023;26(12):1654-1661. doi:10.1089/jpm.2023.0229. PMID:37486715
13. Rosanoff A, Weaver CM, Rude RK. Suboptimal magnesium status in the United States: are the health consequences underestimated?. Nutr Rev. 2012;70(3):153-64. doi:10.1111/j.1753-4887.2011.00465.x. PMID:22364157
14. Axe J. 11 Supplements Every 40+ Adult Should Consider. The Dr. Josh Axe Show; 2026. Video FNhI28uezc8 at 18:51–19:04 (magnesium-rich foods) and 19:34–19:41 (magnesium with vitamin D and omega-3s).
15. National Center for Biotechnology Information. PubChem Compound Summary for CID 5360315, Magnesium chloride (MgCl2, 95.21 g/mol).
16. National Center for Biotechnology Information. PubChem Compound Summary for CID 24644, Magnesium chloride hexahydrate (MgCl2·6H2O, 203.30 g/mol).
17. Purvis JR, Cummings DM, Landsman P, et al. Effect of oral magnesium supplementation on selected cardiovascular risk factors in non-insulin-dependent diabetics. Arch Fam Med. 1994;3(6):503-8. doi:10.1001/archfami.3.6.503. PMID:8081529
18. Macian N, Dualé C, Voute M, et al. Short-Term Magnesium Therapy Alleviates Moderate Stress in Patients with Fibromyalgia: A Randomized Double-Blind Clinical Trial. Nutrients. 2022;14(10). doi:10.3390/nu14102088. PMID:35631229
19. Arii Y, Sano Y, Nishizawa K. Direct comparison of the tofu-like precipitate formation by adding different coagulants: magnesium chloride and glucono-δ-lactone. Heliyon. 2021;7(6):e07239. doi:10.1016/j.heliyon.2021.e07239. PMID:34189298
20. Chandrasekaran NC, Sanchez WY, Mohammed YH, et al. Permeation of topically applied Magnesium ions through human skin is facilitated by hair follicles. Magnes Res. 2016;29(2):35-42. doi:10.1684/mrh.2016.0402. PMID:27624531
21. Proksch E, Nissen HP, Bremgartner M, et al. Bathing in a magnesium-rich Dead Sea salt solution improves skin barrier function, enhances skin hydration, and reduces inflammation in atopic dry skin. Int J Dermatol. 2005;44(2):151-7. doi:10.1111/j.1365-4632.2005.02079.x. PMID:15689218
22. Argeros Z, Xu X, Bhandari B, et al. Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Hypertension. 2025;82(11):1844-1856. doi:10.1161/HYPERTENSIONAHA.125.25129. PMID:41000008
23. Guerrero-Romero F, Tamez-Perez HE, González-González G, et al. Oral magnesium supplementation improves insulin sensitivity in non-diabetic subjects with insulin resistance. A double-blind placebo-controlled randomized trial. Diabetes Metab. 2004;30(3):253-8. doi:10.1016/s1262-3636(07)70116-7. PMID:15223977
24. Simental-Mendía LE, Rodríguez-Morán M, Guerrero-Romero F. Oral magnesium supplementation decreases C-reactive protein levels in subjects with prediabetes and hypomagnesemia: a clinical randomized double-blind placebo-controlled trial. Arch Med Res. 2014;45(4):325-30. doi:10.1016/j.arcmed.2014.04.006. PMID:24814039
25. Bashir Y, Sneddon JF, Staunton HA, et al. Effects of long-term oral magnesium chloride replacement in congestive heart failure secondary to coronary artery disease. Am J Cardiol. 1993;72(15):1156-62. doi:10.1016/0002-9149(93)90986-m. PMID:8237806
26. Albaker WI, Al-Hariri MT, Al Elq AH, et al. Beneficial effects of adding magnesium to desalinated drinking water on metabolic and insulin resistance parameters among patients with type 2 diabetes mellitus: a randomized controlled clinical trial. NPJ Clean Water. 2022;5(1):63. doi:10.1038/s41545-022-00207-9. PMID:36408199
27. Bomar MC, Ewell TR, Brown RL, et al. Short-Term Magnesium Supplementation Has Modest Detrimental Effects on Cycle Ergometer Exercise Performance and Skeletal Muscle Mitochondria and Negligible Effects on the Gut Microbiota: A Randomized Crossover Clinical Trial. Nutrients. 2025;17(5). doi:10.3390/nu17050915. PMID:40077784
28. Rodríguez-Morán M, Guerrero-Romero F. Oral magnesium supplementation improves insulin sensitivity and metabolic control in type 2 diabetic subjects: a randomized double-blind controlled trial. Diabetes Care. 2003;26(4):1147-52. doi:10.2337/diacare.26.4.1147. PMID:12663588
29. de Baaij JH, Hoenderop JG, Bindels RJ. Magnesium in man: implications for health and disease. Physiol Rev. 2015;95(1):1-46. doi:10.1152/physrev.00012.2014. PMID:25540137
30. Barragán-Rodríguez L, Rodríguez-Morán M, Guerrero-Romero F. Efficacy and safety of oral magnesium supplementation in the treatment of depression in the elderly with type 2 diabetes: a randomized, equivalent trial. Magnes Res. 2008;21(4):218-23. PMID:19271419
31. Moabedi M, Aliakbari M, Erfanian S, et al. Magnesium supplementation beneficially affects depression in adults with depressive disorder: a systematic review and meta-analysis of randomized clinical trials. Front Psychiatry. 2023;14:1333261. doi:10.3389/fpsyt.2023.1333261. PMID:38213402
32. Lean ME, Leslie WS, Barnes AC, et al. Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial. Lancet. 2018;391(10120):541-551. doi:10.1016/S0140-6736(17)33102-1. PMID:29221645
33. Asbaghi O, Moradi S, Kashkooli S, et al. The effects of oral magnesium supplementation on glycaemic control in patients with type 2 diabetes: a systematic review and dose-response meta-analysis of controlled clinical trials. Br J Nutr. 2022;128(12):2363-2372. doi:10.1017/S0007114521005201. PMID:35045911
34. Guerrero-Romero F, Rodríguez-Morán M. Magnesium improves the beta-cell function to compensate variation of insulin sensitivity: double-blind, randomized clinical trial. Eur J Clin Invest. 2011;41(4):405-10. doi:10.1111/j.1365-2362.2010.02422.x. PMID:21241290
35. Rodríguez-Morán M, Simental-Mendía LE, Gamboa-Gómez CI, et al. Oral Magnesium Supplementation and Metabolic Syndrome: A Randomized Double-Blind Placebo-Controlled Clinical Trial. Adv Chronic Kidney Dis. 2018;25(3):261-266. doi:10.1053/j.ackd.2018.02.011. PMID:29793665
36. Axe J. Top 10 Natural Pain Killers. Dr. Josh Axe (YouTube); 2016. At 3:33–3:53 (magnesium oil for muscle spasm or tension).
37. Camili V, Stürup S, Heinz A. Does magnesium permeate the skin? An ex vivo investigation of magnesium ion delivery through intact and barrier-disrupted skin. Eur J Pharm Biopharm. 2026;226:115173. doi:10.1016/j.ejpb.2026.115173. PMID:42372834
38. Kass L, Rosanoff A, Tanner A, et al. Effect of transdermal magnesium cream on serum and urinary magnesium levels in humans: A pilot study. PLoS One. 2017;12(4):e0174817. doi:10.1371/journal.pone.0174817. PMID:28403154
39. Coates AM, Patel DV, Binet ER, et al. No Effect of Topical Application of a Commercial Magnesium Gel on Exercise Recovery in Active Individuals. Int J Sport Nutr Exerc Metab. 2025;35(5):416-423. doi:10.1123/ijsnem.2025-0034. PMID:40537122
40. Merschmann R, Burgmer C, Eckert GP, et al. Bioavailability of Magnesium and Potassium Salts Used as Potential Substitutes for Sodium Chloride in Human Nutrition - A Review. Mol Nutr Food Res. 2025;69(22):e70227. doi:10.1002/mnfr.70227. PMID:40931546
41. Axe J. 10 Signs You Have a Magnesium Deficiency (How to Boost Magnesium Naturally). The Dr. Josh Axe Show; 2024. Video vgNbX00pJec (magnesium oxide).
42. Axe J, Cole W. Heal Your Cells. Avery; 2026. Chapter "Reversing Heart Age," magnesium (glycinate or chelate) entry at the p. 367 running head.
43. Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis. BMC Complement Med Ther. 2021;21(1):125. doi:10.1186/s12906-021-03297-z. PMID:33865376
44. Lopresti AL, Smith SJ, Drummond PD. Magnesium Supplementation for Sleep in Adults: A Systematic Review of Randomized Controlled Trials. J Diet Suppl. 2026;23(5):553-581. doi:10.1080/19390211.2026.2719670. PMID:42661485
45. Uwitonze AM, Razzaque MS. Role of Magnesium in Vitamin D Activation and Function. J Am Osteopath Assoc. 2018;118(3):181-189. doi:10.7556/jaoa.2018.037. PMID:29480918

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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