Magnesium supplements are among the most popular supplements in the U.S. But which magnesium supplements are best? ConsumerLab.com announced that it recently tested and reviewed many popular brands of magnesium supplements and found one product to contain only 45.1 percent of its listed magnesium despite boasting a "GMP" (Good Manufacturing Practices) seal on its label. Another violated a FDA labeling rule by displaying a heart symbol although there is no approved heart health claim for magnesium. Several other supplements contained their listed amounts of magnesium, were free of lead contamination, and, if tablets, were able to properly break apart.
Magnesium supplements are commonly used to help prevent magnesium deficiency—which elevates blood pressure and increases the risk of osteoporosis. Deficiency can result from many causes including the extended use of proton-pump inhibitors, such as Nexium and Prilosec. Sales of magnesium supplements reached $430 million in 2011, up 14 percent from the prior year and up 79 percent from 2006, according to Nutrition Business Journal.
ConsumerLab.com found the cost to obtain an equal amount of magnesium from supplements ranged from as little as 2 cents to over $1.30. However, spending a little more than the lowest price may be worthwhile to get a form of magnesium that is better absorbed and less likely to cause diarrhea. Forms covered in the Review are magnesium aspartate and orotate, magnesium citrate, magnesium chloride, magnesium lactate and lactate dehydrate, and magnesium oxide. ConsumerLab.com evaluated magnesium supplements sold as tablets (including caplets and enteric and time-release pills), capsules (including softgels), powders, liquids, as well as calcium-magnesium supplements.
ConsumerLab.com’s review of magnesium supplements includes findings for the 20 products: 11 selected by ConsumerLab.com and nine others that passed ConsumerLab.com's Voluntary Certification Program. Also listed are two products similar to ones that passed testing but sold under different brand names.
The following products are covered in the report: ChildLife Essentials Liquid Calcium with Magnesium, CVS Pharmacy Magnesium, Finest Natural (Walgreen) Magnesium, Life Extension Magnesium, MagOx 400, Mag-Tab SR, Natural Vitality Natural Calm, Nature's Bounty Magnesium, Nature Made High Potency Magnesium, NOW Magnesium Citrate, NutriCology Magnesium Chloride Liquid, Puritan's Pride Premium Magnesium, Purity Products Magnificent Magnesium, Slow-Mag Magnesium Chloride with Calcium, Solaray Magnesium Asporotate, Solgar Magnesium Citrate, Standard Process Magnesium Lactate, Target Up & Up Magnesium, Tropical Oasis Liquid Calcium Magnesium, Twinlab Magnesium Caps, Vitamin Shoppe Minerals Magnesium Citrate, and Vitamin World Magnesium.