Not all Melatonin is alike ...

[JackBruce2024]

Study finds that melatonin content of supplements varies widely:

"... in more than 71 percent of supplements ... the actual content rang[ed] from 83 percent less to 478 percent more than the concentration declared on the label ... Further analysis with mass spectrometry also found serotonin, a much more strictly controlled substance, in 26 percent of the tested supplements. According to the authors, the presence of unlabeled but significant quantities of serotonin could lead to serious side effects."

aasm.org/study-finds-that-m...

Poor Quality Control of Over-the-Counter Melatonin: What They Say Is Often Not What You Get:

jcsm.aasm.org/doi/10.5664/j...