Use case
Best supplements for sleep
Sleep-quality supplements that work without leaving you groggy. Magnesium, ashwagandha, and reishi lead the list.
Why this matters
Sleep is the single most-leveraged variable in this entire category. Fixing chronic sleep deprivation does more for cognition, mood, and energy than any supplement we cover. The honest first question is whether you are sleeping 7 to 8 hours and the issue is sleep quality, or whether you are sleeping 5 to 6 hours and the issue is sleep quantity. For quantity, no supplement substitutes for an hour of bedtime. For quality, the evidence narrows to a small set of well-trialed ingredients. Magnesium glycinate or magnesium L-threonate at 200 to 400 mg before bed has clean trial data on subjective sleep quality and is well-tolerated. Ashwagandha (KSM-66 or Sensoril at 300 to 600 mg/day) reduces cortisol markers and improves subjective sleep onset across multiple RCTs. L-Theanine at 200 mg reduces sleep-onset anxiety in some readers without sedating. Glycine 3 g pre-bed has a smaller but consistent effect on subjective restfulness. Melatonin is the loud option (effective for shifted schedules and jet lag, less reliable for primary insomnia, often dosed 5 to 10x higher than trials suggest). Reishi is traditional but the trial data for sleep specifically is thin. The protocol below is what we recommend trying first when behavioral interventions (consistent bedtime, dark room, no screens 60 min pre-bed, no alcohol close to bed) have already been addressed.
Featured supplements
Strongest sleep-Mg evidence
Magnesium L-Threonate
The only magnesium form with mechanistic evidence for raising brain magnesium levels. Sleep-quality and cognitive trials are recent, small, and largely industry-funded.
Strongest stress evidence
Ashwagandha
An adaptogen with the strongest meta-analysis evidence in the category for stress, anxiety, and cortisol modulation. KSM-66 and Sensoril are the two extracts with the most trial data.
Reishi
A traditional medicinal mushroom for immune support. Sleep-quality evidence is preliminary, mostly murine; no large RCT in healthy adults with primary insomnia.
What works
- Magnesium glycinate or L-threonate 200-400 mg, 30-60 minutes before bed.
- Ashwagandha (KSM-66 or Sensoril) 300-600 mg daily, taken any time but at least 4 weeks consistent for the cortisol effect to build.
- L-Theanine 200 mg pre-bed for readers whose primary issue is sleep-onset anxiety rather than circadian timing.
- A consistent bedtime within a 30-minute window, 6 nights a week. Shifts of more than 90 minutes break the rhythm faster than any supplement can fix.
- Treating bright-light exposure in the morning as part of the protocol - the supplement only works on top of a working circadian system.
- Glycine 3 g pre-bed if subjective restfulness is the issue and you have already tried magnesium.
What doesn't
- High-dose melatonin (5-10 mg) for primary insomnia. Trials use 0.3-1 mg; over-the-counter doses are routinely 10x trial dose with no upside and a residual grogginess risk.
- Stacking 4 sedating compounds (ashwagandha + magnesium + L-Theanine + melatonin) on the same night - compound grogginess in the morning is the typical outcome.
- Reishi as a standalone sleep supplement - the trial data for sleep is thin compared to magnesium or ashwagandha.
- CBD products without dose disclosure or third-party testing - the supplement-grade CBD market is full of products that do not contain what the label claims.
- Alcohol as a sleep aid. It hastens sleep onset and demolishes sleep architecture; the second half of the night is fragmented even when total sleep time looks similar.
- Reaching for any supplement before fixing screen exposure within 60 minutes of bed.
Suggested protocol
First sleep protocol (4-6 weeks)
Single-ingredient baseline. Start with magnesium because it is the cleanest evidence for the broadest issue (subjective sleep quality). Add ashwagandha after week 4 only if cortisol-driven racing thoughts are the dominant issue. Skip everything else for the first 90 days. The behavioral side (consistent bedtime, morning light, no screens pre-bed, no alcohol within 3 hours of bed) is non-negotiable - the supplement only works on top of those.
- Magnesium glycinate or L-threonate 200-400 mg elemental magnesium
Timing: 30-60 min before bed
Glycinate is gentler on the gut. L-threonate has limited brain-penetration evidence and is more expensive; either is acceptable. Avoid magnesium oxide (poorly absorbed, gut effects).
- Ashwagandha (KSM-66 or Sensoril) 600 mg KSM-66 OR 250 mg Sensoril
Timing: Any time of day, with food
Add at week 4 if magnesium alone is not enough and your primary issue is racing thoughts at sleep onset. Cycle 8 weeks on, 2 weeks off if used long-term.
- Behavioral foundation (non-supplement) Same bedtime within 30 min, 6 nights/week
Timing: Daily
Bright light exposure in the first hour after wake. No screens 60 min pre-bed. No alcohol within 3 hours of bed. The supplements are leverage on a working system.