The 5 Best Supplements for Better Sleep (Backed by Science)
Forget melatonin. These five evidence-led supplements address the actual root causes of poor sleep — stress, low magnesium, and circadian disruption.
If you've been reaching for melatonin to sleep, you're probably using it wrong. Melatonin is a signal molecule — useful for jet lag, not chronic insomnia. The real lever for better sleep is supporting the systems your body uses to wind down: cortisol, GABA, body temperature, and magnesium balance.
Here are the five supplements with the strongest evidence for sleep quality.
1. Magnesium glycinate
Dose: 300–400 mg elemental, 30–60 minutes before bed.
Magnesium activates GABA receptors and helps muscles relax. Glycinate is the gentlest, most calming form. Most studies show meaningful improvements in sleep latency and quality within 2–4 weeks.
2. Ashwagandha (KSM-66)
Dose: 300–600 mg standardised extract, evening.
An adaptogen that lowers cortisol — the stress hormone that keeps you wired at night. Clinical trials show measurable improvements in sleep onset and quality, especially in people with anxiety or stress-driven insomnia.
3. Glycine
Dose: 3 g, 30–60 minutes before bed.
Glycine lowers core body temperature, which is a key trigger for falling asleep. Studies in Japan show improved sleep depth and morning alertness with consistent use.
4. L-theanine
Dose: 200 mg in the evening.
Promotes alpha brain waves — the same waves that dominate during meditation. It quiets racing thoughts without sedation, which makes it a great pair with magnesium.
5. Low-dose melatonin
Dose: 0.3–1 mg, 90 minutes before target bedtime.
Most melatonin gummies contain 5–10 mg — far too much. Lower doses (0.3 mg) are actually more effective as a phase shifter, especially for shift workers and travel.
Lifestyle wins more than pills
Before stacking supplements, get the basics right:
- Same bedtime ±30 minutes
- No bright light 60 minutes before bed
- Cool room (16–19°C)
- No caffeine after 2pm
Supplements are a multiplier on good habits — not a replacement.
Want a stack matched to you? Take our 3-minute quiz →