The supplement aisle sells sleep harder than almost anything — and most of it underdelivers. A handful genuinely help at the right dose; several are hype; the sleep 'peptides' are essentially unproven. Here's the honest grading.
The best-supported, in rough order: glycine 3 g before bed (lowers core temperature, speeds onset); magnesium (glycinate, ~200–400 mg elemental — best if you're deficient); ashwagandha (KSM-66, 300–600 mg for 8+ weeks — the best-evidenced adaptogen, working by lowering stress and cortisol, ideal for the 'wired and tired'); and L-theanine 200 mg or oral lavender (Silexan) 80 mg for anxiety-driven insomnia. All genuine, all modest, all safe. Evidence ●●●○○
GABA (a pill probably can't reach the brain — the mechanism marketing is misleading), isolated apigenin (chamomile's active compound, but no human trial of the isolate), valerian and L-tryptophan (the sleep guidelines recommend against both), and taurine/magnolia (animal data only). Tart cherry is mildly real but comes with a lot of sugar in juice form. Evidence ●●○○○
DSIP (delta sleep-inducing peptide) and epitalon are marketed for sleep, but the human evidence is thin-to-absent — DSIP's few positive studies were tiny, decades old, given intravenously, and never replicated — and they're unregulated gray-market injectables with no approved use. Interesting names; no real evidence, and real purity/dosing risk. Evidence ○○○○○ in humans
The biggest wins aren't in a bottle
Supplements are edge-optimisers on top of the fundamentals — useful, but small. Fix the room, the light, and the schedule first; a stack of magnesium and glycine can't rescue a chaotic bedtime or an untreated snore.
The Sleep Guide