For this study, researchers analyzed 30 melatonin supplements purchased from local grocery stores in Canada (one of the few countries, besides the United States, where melatonin is available without a prescription). They tested to see how the amount of melatonin in the supplement matched the amount listed on the bottle.
“Melatonin content was found to be highly variable between samples and batches, with no observed patterns between brand, supplement form, labeled value, or the presence of other herbal extracts,” the report said. the study results section says. The actual amount of melatonin ranged from -83% to +478% in the samples tested, meaning some had levels 478% higher than stated on the bottle (while others contained less melatonin than what was promised on the Supplement label).
“Additionally, the lot-to-lot variability within a particular product varied by up to 465%,” adds Ellen Wermter, FNP-BC, Family Nurse Practitioner and spokesperson for the Tips for better sleep.
“Even Scarier,” Christina Graham, Registered Nurse and Coach namesays of the revealing study, “Tests also found serotonin in 26% of the samples. Serotonin is more tightly controlled, and the presence of unlabeled serotonin in significant amounts could lead to serious side effects.”