Magnesium Glycinate is a supplement that works wonders for falling asleep - and likewise for melatonin
And that's just top of my head. I'm quite certain some doctors would like to ban supplements, but I think it may be due more to their desires to remove competition from the market
Just a non-essential amino acid that is a precursor for dopamine (and epinephrine/norepinephrine by extension), 2 thyroid hormones, and interestingly enough, melanin.
Not medical advice. My point is that it turned out what I needed was a "supplement".
Having more options is better than having less, so I don't see supplements ever going away - if anything, I believe they will grow in places where they are not as big yet (say, EU) and where there is no competition (so not in Asia due to TCM)
Magnesium is required for serotonin production. And modern farming practices virtually eliminate it from our diet.