By goal
Evidence-Backed Supplements for Sleep and Insomnia
Sleep is one of the most-supplemented goals, but the evidence behind popular options varies widely, from well-studied (melatonin) to promising-but-thin (glycine) to genuinely mixed (valerian). We grade each substance by what the research actually shows, including dosing context and safety notes. This is not a substitute for sleep hygiene or a clinician's input on persistent insomnia.
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Best-supported here: Ashwagandha (Moderate), Holy Basil (Tulsi) (Moderate), Inositol (Myo-Inositol) (Moderate), Kava (Moderate) — each graded below by the weight of human evidence.
| Supplement | Evidence for this goal | Typical dose | Key caution | Studies |
|---|---|---|---|---|
| Ashwagandha | Moderate for this goal | 300–600 mg/day of root extract (standardized to 5% withanolides), often… | Avoid in pregnancy (traditionally abortifacient) and while breastfeeding. | 18 |
| Holy Basil (Tulsi) | Moderate | ~300 mg/day of standardized extract (or brewed leaves). | Generally safe. | 14 |
| Inositol (Myo-Inositol) | Moderate | PCOS: typically 2 g myo-inositol twice daily (4 g/day), often with 400… | Generally well tolerated; the most common side effects are mild, dose-related gastrointesti… | 14 |
| Kava | Moderate | Standardized extracts ~120–280 mg kavalactones/day, short-term (≤8 week… | ⚠ Rare but serious liver injury. | 14 |
| Kiwifruit | Moderate | Two green kiwifruit daily (about 140-180 g) is the dose used in most co… | Kiwifruit is a recognised allergen and can cause oral allergy syndrome or, rarely, anaphyla… | 8 |
| L-Theanine | Moderate for this goal | 100–200 mg; often paired 1:2 with caffeine (e.g. 100mg theanine + 50mg… | Very safe, no known serious side effects. | 16 |
| Saffron | Moderate for this goal | 30 mg/day standardized extract. | Safe at supplement doses. | 20 |
| Sweet Cherry | Moderate | 1 cup pitted (about 138 g, ~21 cherries) fresh; many trials use 200-300… | Generally safe as a food. | 8 |
| Tart Cherry | Moderate | Common food serving is about 1 cup (155 g) of fresh pitted sour cherrie… | Generally safe as a food. | 10 |
| 5-HTP | Preliminary for this goal | 50–300 mg/day; start low. Do NOT combine with antidepressants. | GI upset common. | 15 |
| Glycine | Preliminary for this goal | 3 g before bed for sleep. | Very safe. | 16 |
| Magnesium | Preliminary for this goal | 200–400 mg elemental/day. Glycinate & citrate absorb best; oxide is poo… | Safe. | 20 |
| Reishi | Preliminary | 1.5–9 g/day of extract (standardized to polysaccharides/triterpenes). | Generally safe for a few months. | 17 |
| Melatonin | Mixed for this goal | 0.5–3 mg, 30–60 min before target bedtime. Lower doses often work as we… | Safe short-term. | 18 |
| Valerian Root | Mixed | 300–600 mg extract 30–60 min before bed. | Generally safe short-term. | 15 |