However, it found brands differed on how labels portrayed the amount of potassium in the products. Potassium is chemically unstable and, therefore, is always bound to compounds which stabilize it. Potassium makes up far less than half of the weight of most of these potassium compounds, accounting for only 16.7% of the weight of potassium gluconate, 38.3% of potassium citrate and 52% of potassium chloride. Consequently, a product named "Potassium Gluconate 595 mg" will actually contain only about 99 mg of active “elemental” potassium. This important fact may be missed by many consumers when only disclosed in the “Supplement Facts” panel on the back of the bottle.
"We are glad that the findings for this group of potassium products were positive, but consumers should be aware that this is not always the case. In addition, they must carefully read the “Supplement Facts” panel on labels to be sure they are choosing a product with the right dose of potassium," said Tod Cooperman, M.D., ConsumerLab.com's president.
ConsumerLab.com’s Potassium Supplements Review is available at https://www.consumerlab.com/reviews/Potassium_Supplements/Potassium/. It includes quality ratings, price comparisons, and ingredient comparisons for seven products selected, tested, and rated by ConsumerLab.com as well as for eight that passed ConsumerLab.com's Quality Certification Program. Also listed are two products similar to one that passed testing. Potassium supplement products included in the report are 21st Century Potassium Gluconate 595 mg, CVS/pharmacy Potassium Gluconate 595 mg, Douglas Laboratories Potassium 99 mg Chelated, Finest Nutrition Potassium Gluconate, KAL Potassium 99 Chloride, Natural Factors Potassium Citrate 99 mg, Nature Made Potassium Gluconate, Natures Bounty Potassium Gluconate 595 mg, NOW Potassium Chloride Powder, Puritans Pride Potassium, Simply Right Potassium Gluconate 595 mg, Solgar Potassium, Sundown Naturals Potassium Gluconate 595 mg, Thorne Research Potassium-Magnesium Citrate, Twinlab Potassium Caps, The Vitamin Shoppe Potassium Citrate, and Vitamin World Potassium 99 mg.
The report also provides information about the forms of potassium, dosage for specific uses, concerns and cautions with potassium supplement use, and additional clinical information.
ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to ConsumerLab.com is available online, providing immediate access to independent reviews of more than 1,000 products. The company is privately held and based in Westchester, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products. ConsumerLab.com is affiliated with PharmacyChecker.com, which helps consumers evaluate online pharmacies and compare drug prices, and MedicareDrugPlans.com, which reviews and rates Medicare Part D plans.