Okay but
how are people using it? It can so easily be misused: it's a signalling hormone that resets the phase alignment of the
circadian rhythm. Yet so many people just eat it randomly like a sleeping pill. That's bound to be damaging in the long term. It shouldn't be necessary to take it every single night. If you're having trouble sleeping every single night, you've got other issues. Maybe you're stressed out by the world you live in. Maybe it means you're taxing your central nervous system, throttling it constantly. You need to go around the glutamate–glutamine cycle more often than you can sustain. There are metabolic costs to doing this. Maybe you've been eating food from soil devoid of minerals like magnesium, a critical cofactor in the glutamate-glutamine cycle. In fact people struggling with chronic stress have been shown to be statistically more likely to be insufficient or deficient in magnesium.
But you take melatonin because nobody wants to tell you all this. And you take it at random times thereby fucking up your circadian rhythm even worse.
Don't get me started on vitamin D and how that's _also_ a circadian phase signaller, but how I never see those big flashy press releases about whether or not vitamin D is good or bad ever go into this.
Why do I have so little faith that they controlled for timing in the study?