Nine ingredients are sold for sleep. Three have trials behind them, and all three work better in people who were short of something to begin with.
High-dose melatonin gummies, "PM" blends and kava — high-dose melatonin causes next-day grogginess without better sleep, proprietary PM blends hide their doses, and kava carries a genuine hepatotoxicity signal. If a product lists "sleep blend 640 mg" without a breakdown, there is nothing there to evaluate.
Consistent wake time moves sleep onset more than any ingredient on this page.
The studied dose is a fraction of the retail dose. More causes grogginess, not more sleep.
Untreated apnoea, alcohol and late caffeine outweigh every supplement here.