Why it's in the formula. Magnesium is involved in the regulation of neurotransmitters that govern the sleep–wake cycle and in normal muscle function. It's one of the more commonly studied minerals in sleep research, and dietary intake falls short of recommended levels for a large share of adults.

What the research shows. The largest placebo-controlled trial of magnesium and sleep was published in Nature and Science of Sleep in 2025. 155 adults aged 18–65 with self-reported poor sleep took 250 mg of elemental magnesium as bisglycinate, or placebo, for four weeks. Insomnia Severity Index scores improved more in the magnesium group than in placebo (3.9 points versus 2.3, p = 0.049). Most of the improvement showed up within the first two weeks and held. The supplement was well tolerated — side effects were less frequent than in the placebo group.

Why bisglycinate. Magnesium oxide is cheap and poorly absorbed. Citrate is better absorbed but has an osmotic laxative effect. Bisglycinate is a chelated form generally chosen for GI tolerability — which matters in something you drink before bed.

Why it's in the formula. Glycine is an amino acid that acts as an inhibitory neurotransmitter. It also causes peripheral vasodilation, which lowers core body temperature — the same drop your body produces naturally as it moves toward sleep.

What the research shows. A 2007 trial in Sleep and Biological Rhythms gave 3 g of glycine before bed to people with poor subjective sleep quality and found improvements in sleep quality ratings compared with placebo. A later trial reported reduced daytime sleepiness and fatigue in sleep-restricted subjects at the same dose.

Why it's in the formula. L-theanine is an amino acid found in tea leaves. EEG studies have associated it with increased alpha-wave activity — the brain state linked to relaxed wakefulness rather than sedation. It's the ingredient in the formula meant to quiet mental activity without making you groggy.

What the research shows. A 2019 randomized, placebo-controlled trial in Nutrients gave 200 mg of L-theanine daily to healthy adults for four weeks. Pittsburgh Sleep Quality Index scores improved compared with placebo, with significant differences in the sleep latency, sleep disturbance, and sleep-medication subscales.

Why this one matters to us. It's the only ingredient in QuietHour where our dose exactly matches the dose in the trial.

Why it's in the formula, and why the dose is low. This is the ingredient we're most confident about, and the reason is counterintuitive: most sleep products use far too much. Typical melatonin supplements deliver 3–10 mg. Your body produces roughly 0.1–0.3 mg per night. Research from MIT in 2001 established that physiological doses — around 0.3 mg — were effective for sleep onset, and that higher doses didn't perform better while being more likely to produce next-day grogginess.

What the research shows. The 2001 trial in the Journal of Clinical Endocrinology & Metabolism compared physiological-range melatonin against placebo and against higher doses, and found the low dose effective for sleep onset. Meta-analyses since have found melatonin reduces the time it takes to fall asleep and modestly increases total sleep time.

Why it's in the formula. Reishi (Ganoderma lucidum) has centuries of traditional use in East Asian medicine as a calming, restorative mushroom. Dual extraction — water and alcohol — is used because different compounds in the mushroom are soluble in different solvents.

What the research shows. A 2024 systematic review and meta-analysis in the Journal of Ethnopharmacology pooled randomized controlled trials of Ganoderma lucidum and reported improvements in sleep outcomes.

Why it's in the formula. Montmorency tart cherries naturally contain melatonin along with procyanidins that may affect tryptophan availability. It's a whole-food source of the same compound we dose directly, plus polyphenols the isolated compound doesn't provide.

What the research shows. A 2012 trial in the European Journal of Nutrition gave participants tart cherry juice concentrate twice daily for seven days and measured increases in urinary melatonin along with improvements in total sleep time and sleep efficiency.

We're going to be straight with you about this one.

Apigenin is a flavonoid found in chamomile. In laboratory and animal research it binds to benzodiazepine sites on GABA-A receptors, which is the mechanism behind chamomile's long reputation as a calming tea. That mechanism is well described.

What the research does not show. There is no randomized controlled trial of isolated apigenin for sleep in humans, at 50 mg or at any other dose. The chamomile literature is mixed: the most-cited trial in adults with chronic insomnia found no significant difference from placebo on any sleep diary measure.

Why it's still in the formula. Chamomile has a long history of traditional use for relaxation before bed, the receptor mechanism is real, and 50 mg is a well-tolerated amount. But we're not going to link you to a study that doesn't exist, and we're not going to describe apigenin as clinically proven for sleep. It isn't.