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.
| 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. | 20 |
| Holy Basil (Tulsi) | Moderate | ~300 mg/day of standardized extract (or brewed leaves). | Generally safe. | 15 |
| 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… | 16 |
| Kava | Moderate | Standardized extracts ~120–280 mg kavalactones/day, short-term (≤8 week… | ⚠ Rare but serious liver injury. | 16 |
| 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… | 9 |
| 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. | 18 |
| Saffron | Moderate for this goal | 30 mg/day standardized extract. | Safe at supplement doses. | 22 |
| Sweet Cherry | Moderate | 1 cup pitted (about 138 g, ~21 cherries) fresh; many trials use 200-300… | Generally safe as a food. | 9 |
| Tart Cherry | Moderate | Common food serving is about 1 cup (155 g) of fresh pitted sour cherrie… | Generally safe as a food. | 11 |
| 5-HTP | Preliminary for this goal | 50–300 mg/day; start low. Do NOT combine with antidepressants. | GI upset common. | 17 |
| Glycine | Preliminary for this goal | 3 g before bed for sleep. | Very safe. | 17 |
| Magnesium | Preliminary for this goal | 200–400 mg elemental/day. Glycinate & citrate absorb best; oxide is poo… | Safe. | 22 |
| Reishi | Preliminary | 1.5–9 g/day of extract (standardized to polysaccharides/triterpenes). | Generally safe for a few months. | 19 |
| Melatonin | Mixed for this goal | 0.5–3 mg, 30–60 min before target bedtime. Lower doses often work as we… | Safe short-term. | 20 |
| Valerian Root | Mixed | 300–600 mg extract 30–60 min before bed. | Generally safe short-term. | 16 |
Supplements for Sleep and Insomnia — common questions
What is the best supplement for sleep and insomnia?
Melatonin has the strongest evidence here, and it is the only sleep supplement we grade as strong. It is the body's own sleep-timing hormone, so it works best for shifting when you feel sleepy rather than for knocking you out. Magnesium, L-theanine, and tart cherry sit a tier below at moderate evidence. Expect a modest nudge, not a sedative.
How much melatonin should I take, and how long before it works?
Most people do well on 0.5 to 3 mg taken 30 to 60 minutes before your target bedtime; lower doses often work as well as higher ones, so there is little reason to start big. Timing matters more than dose. If you are trying magnesium instead, 200 to 400 mg of elemental magnesium daily is typical, with glycinate or citrate absorbing best. Timelines vary a lot between people.
Is it safe to take sleep supplements with my medications?
Melatonin can interact with anticoagulants and sedatives, and may leave you groggy or give you vivid dreams. Kava carries a rare but serious risk of liver injury and should not be combined with alcohol, liver disease, hepatotoxic drugs, or sedatives. Magnesium needs caution in kidney disease, and ashwagandha should be avoided in pregnancy and breastfeeding. Run your full list past a doctor or pharmacist before starting anything.
Do magnesium and tart cherry actually help you sleep?
Both are graded moderate, which means promising but not settled. Tart cherry is often marketed for sleep, yet the human data remains preliminary and concentrates carry a real sugar load. Magnesium mostly helps if you are low to begin with. L-theanine is very safe but non-sedating at typical doses, so it calms rather than causes sleep. Honestly, none of these rival good sleep habits.