Content Uniformity of Over-the-Counter Melatonin

Dietary supplements are loosely regulated in comparison to over-the-counter and prescription drugs. Numerous tests for safety and efficacy are required before drugs can be marketed. However, the Food and Drug Administration does not require thorough examination of supplements before they are sold. Dietary supplements generally adhere to the phrase, “safe, until proven unsafe,” with safety determined solely through post-market adverse event reports. Substandard regulation of supplement manufacturing leads to warranted doubt about the safety and efficacy of dietary supplements. Within the dietary supplement market there are regulatory bodies, such as the United States Pharmacopeia (USP), that provide optional verification services to manufacturers. If utilized, these regulatory bodies ensure that manufacturers meet specific standards in regard to Current Good Manufacturing Practices (cGMP), purity of ingredients, and overall integrity of their product. Numerous studies have revealed a history of inaccuracies in supplement product labeling. Researchers conducting these studies consistently conclude that there is a need for stricter regulation and finer application of cGMP within supplement manufacturing companies. One of the most popular dietary supplements on the market, melatonin, has been the focus in a number of studies evaluating supplement product content integrity. Melatonin is commonly used to treat insomnia and to cure symptoms of jet lag. According to past research, these melatonin products often contain an amount of active ingredient that significantly differs from respective product labeling. Most research regarding melatonin product integrity has occurred outside of the past ten years, leaving the need for newer research. Melatonin 3 mg will be purchased from six different manufacturers with three manufacturers possessing USP verification. Within each manufacturer, melatonin 3 mg from five separate lot numbers will be purchased. Ten tablets from each bottle (totaling 300 tablets) will be analyzed using a high-pressure liquid chromatography machine in order to determine actual melatonin content in each tablet. Data will be recorded and compared to determine accuracy of product labeling and batch-to-batch content uniformity. Data from USP-verified melatonin will be compared with non-verified products in order to determine if regulatory body verification is effective at improving content uniformity