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ConsumerLab Tests Magnesium Supplements, Spots Problems and Selects a Top Pick
White Plains, NY, May 7, 2024 — Nearly half the U.S. population does not get adequate amounts of magnesium and may benefit from increasing magnesium intake from foods or supplementation. Getting adequate intake of magnesium can improve vitamin D levels, improve glucose status in people with prediabetes, and have cardiovascular benefits. Magnesium supplements are the second-most popular supplement, taken by over half of regular supplement users. However, with so many different forms of magnesium available, it can be difficult to know which products contain what they claim and provide the best form and dosage to suit an individual’s needs.

To identify the best magnesium supplements, ConsumerLab recently purchased 15 popular magnesium supplements, and carefully tested them to see if they contained what they claimed, and whether they were contaminated with toxic metals such as lead, arsenic, cadmium, and mercury.

Key Findings:

  • Magnesium Quality: Two magnesium supplements were Not Approved because they appeared to contain a different form of magnesium than listed on the label, based on the percentage of listed ingredient found to be magnesium. The quality of other products was generally high, although this does not necessarily reflect the quality of most products on the market, as ConsumerLab selects products that have demonstrated high quality in its previous tests as well as those popular among ConsumerLab members, who are generally well-informed consumers and health professionals.
  • Magnesium Dose: There was a wide range in the dose of magnesium provided by products, ranging from 76 to 500 mg per suggested serving. Dosage is important to be aware of, as many people will only need no more than 200 mg of supplemental magnesium to meet the suggested daily intake, and doses over 350 mg increase the risk of diarrhea and other side effects.
  • Cost:The cost to obtain 200 mg of magnesium from products varied significantly, from 2 cents to more than $1.00. Products with certain chemical forms of magnesium, special formulations or extra ingredients were more expensive.
CL selected a Top Pick magnesium supplement that not only passed its tests and is relatively inexpensive, but provides magnesium in a form that is relatively well-absorbed and unlikely to cause diarrhea at moderate dosage. For a higher dose, CL suggested a product containing a different form of magnesium that is unlikely to cause diarrhea at high dosage.

Access the Full Report:

If you are one of more than 95,000 ConsumerLab members who support ConsumerLab’s research, you can now access the full Magnesium Supplements Review.

The report includes test results and comparisons for fifteen magnesium products, including moderate and high-dose pills, powders, liquids, and gummies. Ten products were selected for testing by ConsumerLab: BIOptimizers Magnesium Breakthrough, Bluebonnet Magnesium Aspartate, Magnesium Glycinate, Doctor’s Best High Absorption Magnesium, Natural Vitality Calm – Raspberry-Lemon Flavored, Nature Made Extra Strength Magnesium 400 mg, NOW Magnesium Citrate, NutriCology Magnesium Chloride Liquid, Pure Encapsulations Magnesium (Glycinate), and Swanson Triple Magnesium Complex. Five additional products passed the same testing and were Approved through CL's voluntary Quality Certification Program: Garden of Life Dr. Formulated Magnesium with Pre & Probiotics Gummies – Raspberry Flavor, GNC Magnesium 500 mg, InnovixLabs Advanced Magnesium, Jigsaw Health MagSRT, and Life Extension Neuro-Mag.

The Review also explains the pros and cons of different forms of magnesium, which are best absorbed, and which are more or less likely to have a laxative effect, as well as potential side effects and drug interactions. It also reviews the evidence for or against use of magnesium for conditions including migraine, anxiety, sleep, memory, and leg cramps.

A video with expert tips for selecting the best magnesium supplements is also available.

Founded in 1999, is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to is available online and provides immediate access to continually updated reviews of nearly every popular type of dietary supplement and health food, answers to reader questions, and product recalls and warnings. ConsumerLab also provides independent product testing through its voluntary Quality Certification Program. The company is privately held and based in New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.

Tips on Choosing the Right Magnesium Supplement - Tod Cooperman, MD

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