Magnesium Supplements - Why Are There So Many Choices?
Magnesium plays a role in more than 300 biochemical reactions in the body, including muscle contraction, nerve function, blood sugar regulation, and sleep quality. Because many adults fall short of the recommended intake, magnesium supplements have become increasingly popular in recent years (NIH Office of Dietary Supplements, 2022). But not all forms are created equal, and choosing the wrong one can mean wasted money, unwanted side effects, or no real benefit.
Here’s a breakdown of the most common forms of magnesium and what the research shows they’re best used for.
Magnesium Citrate
Magnesium citrate is well absorbed and has a mild laxative effect.
Best for: constipation, general supplementation.
Evidence: Shown effective for bowel regulation in clinical trials (Ford & Suares, Am J Gastroenterol, 2011).
Magnesium Glycinate (or Bisglycinate)
Chelated to glycine, which supports calming neurotransmitter activity; well absorbed with fewer gastrointestinal effects.
Best for: anxiety, sleep, migraine prevention, muscle tension.
Evidence: Glycine has demonstrated calming and sleep-enhancing effects (Bannai & Kawai, Neuropsychopharmacol Reports, 2022); magnesium supplementation reduces migraine frequency in many individuals (American Headache Society, 2021).
Magnesium Oxide
Contains high elemental magnesium but is poorly absorbed; effective as a laxative.
Best for: constipation, heartburn.
Evidence: Low bioavailability confirmed in absorption studies (Firoz & Graber, Magnes Res, 2001).
Magnesium L-Threonate
Notable for its ability to cross the blood–brain barrier more effectively than other forms.
Best for: cognitive support, memory, focus.
Evidence: Animal and early human trials show improved cognitive performance (Slutsky et al., Neuron, 2010); research is promising but still developing.
Magnesium Malate
Bound to malic acid, which plays a role in energy production.
Best for: fatigue, muscle pain, exercise recovery.
Evidence: Malic acid has been studied for fibromyalgia-related pain reduction (Russell et al., J Rheumatol, 1995).
Magnesium Taurate
Combined with taurine, which has heart calming and blood pressure supporting effects.
Best for: cardiovascular health, arrhythmia support.
Evidence: Taurine demonstrated benefits for blood pressure and cardiac function in small human trials (Zhang et al., Hypertension Research, 2004).
Choosing the Right Form Isn’t One-Size-Fits-All
Your ideal magnesium supplement depends on your health goals, digestion, medications, kidney function, and even how you sleep. The dose also matters as too much can cause diarrhea, interact with medications, or, in rare cases even affect heart rhythm (NIH ODS, 2022).
Working with a Registered Dietitian ensures you’re choosing the safest, most effective form for your individual needs. If you're curious about magnesium for sleep, stress, gut health, or chronic symptoms, this is the perfect time to schedule a personalized nutrition consultation with a Registered Dietitian at Northern Nutrition Group.
References
National Institutes of Health, Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. 2022.
Ford AC, Suares NC. Effect of laxatives and pharmacological therapies in chronic constipation: systematic review and meta-analysis. Am J Gastroenterol. 2011.
Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Neuropsychopharmacol Reports. 2022.
American Headache Society. Evidence-based guideline update: pharmacologic treatment for episodic migraine. 2021.
Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001.
Slutsky I et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010.
Russell IJ et al. Treatment of fibromyalgia syndrome with Super Malic: a randomized, double-blind, placebo-controlled trial. J Rheumatol. 1995.
Zhang M et al. Beneficial effects of taurine on blood pressure and vascular function. Hypertension Research. 2004.
Written by Kylie Conner
Kylie specializes in: Oncology - supporting individuals through cancer treatment, remission, malnutrition, food aversions, enteral nutrition, and preventive strategies. PCOS & Fertility - weight-inclusive care for hormonal balance, menstrual health, and fertility support. Cardiovascular Disease - heart disease, high cholesterol, high blood pressure, and related conditions. Chronic Disease Prevention and Management - focusing on sustainable, non-restrictive approaches to improve long-term health and reduce risk.