ConsumerLab.com tests found more than 100 mg of potentially beneficial PACs in some supplements, while others had less than 1 mg in a daily serving. It's questionable whether those with smaller amounts would be effective. Some extracts actually had much lower concentrations of PACs than plain ground cinnamon bark. ConsumerLab found that consumers can pay as little as 5 cents or as much as $134 to get the same amount of PACs.
Regarding coumarin, some products had amounts of concern. A single teaspoonful of cinnamon from two of the spices contained amounts above the tolerable daily intake level for adults—and way over that for children if consumed on a regular basis.
ConsumerLab.com also checked products made from cinnamon powder for potential contamination with Salmonella and heavy metals. Spices were additionally tested for filth. All products passed those tests.
The test results and quality ratings appear online in ConsumerLab.com's new Cinnamon Supplements and Spices Review. The report covers seven supplements and three spices selected for testing by ConsumerLab.com, and two supplements which passed the same tests in ConsumerLab.com's voluntary Quality Certification Program.
In addition to tests and comparisons, the report reviews clinical evidence for cinnamon, including dosage, safety, side effects and potential drug-interactions.