Medicine's Dennis Auckley explains the comparisons between melatonin and magnesium

Should I take melatonin, magnesium, or both to sleep better? 

SELF Magazine: Dennis Auckley, professor at the School of Medicine, said there are no direct studies comparing melatonin and magnesium for sleep, and research on both—especially for typical insomnia—is limited and often small or short-term. He advised improving sleep habits first, noting supplements may offer only modest benefits and should be used cautiously.