5 Sleep Supplements Worth Taking
In my previous article, we covered five freely available sleep interventions: morning light, a cool bedroom, consistent sleep timing, a pre-bed shower, and an earlier coffee cut-off. Total cost: zero dollars. Start there if you haven't. No supplement replaces good habits.
That said, a small subset of supplements have genuine clinical evidence behind them. Not marketing claims, but randomised controlled trials and meta-analyses (studies that combine data from multiple trials to draw stronger overall conclusions). Here are five that have earned their place.
1. Melatonin
Melatonin is a hormone your brain already makes. The pineal gland releases it when darkness falls, signalling that the day is over. Supplementing with it doesn't knock you out. It nudges your internal clock and works best for difficulty falling asleep and circadian rhythm disruption such as jet lag and shift work.
The evidence base is the strongest of any sleep supplement. A 2024 meta-analysis of 26 randomised controlled trials found that melatonin significantly reduced sleep onset latency (the time it takes to fall asleep) and increased total sleep time, with effects peaking at around 4mg per day[¹]. A systematic review of 8 trials and 1,847 participants found consistent improvements in subjective sleep quality (how well participants felt they had slept, based on their own experience) [²], with an average reduction in time to fall asleep of around 7 minutes[³].
The clinical dose is 0.5 to 2mg, taken 30 to 60 minutes before bed. Many products contain 5 to 10mg, which exceeds what the body naturally produces and can cause grogginess or suppress your own melatonin production over time. More is not better here.
Important note: In Australia, melatonin is tightly regulated. If you are under 55, you will need a prescription from your GP. If purchasing online, look for NSF and ISO certification on the label to ensure quality and independent testing.
2. L-Theanine
L-theanine is an amino acid found in green tea. Rather than sedating you, it reduces the physiological arousal that keeps you from falling asleep, making it well-suited to people whose sleep is disrupted by an overactive mind.
A 2025 meta-analysis in Sleep Medicine Reviews covering 19 trials and 897 participants found significant improvements in sleep onset latency (time to fall asleep), daytime functioning, and overall sleep quality[⁴]. Objective measures did not show significant change in sleep architecture (the pattern of sleep stages, including light sleep, deep sleep and REM, that make up a night of rest), so the benefit is mainly in how people experience their sleep and function the next day.
The dose is 200 to 400mg taken 30 to 60 minutes before bed, with no dependency risk and no known medication interactions.
3. Magnesium (Glycinate or Bisglycinate)
Magnesium activates the brain's calming signals while suppressing those that drive wakefulness, and low levels are associated with elevated cortisol and disrupted sleep. It is one of the most common nutritional deficiencies in Western diets.
Form matters. Magnesium oxide, found in most cheap supplements, has poor absorption. Glycinate and bisglycinate forms are far better absorbed, and the amino acid they are bound to (glycine) independently helps lower core body temperature at night, supporting the body's natural sleep process.
Two clinical trials support their use: a 2025 randomised controlled trial in 155 participants found bisglycinate significantly reduced insomnia severity over four weeks[⁵], while an earlier trial in elderly patients showed improvements in sleep efficiency, total sleep time, and melatonin levels after eight weeks on 500mg[⁶]. The benefit appears strongest in people with low dietary magnesium intake, which includes more of the population than most people expect.
The dose is 200 to 400mg of elemental magnesium as glycinate or bisglycinate, taken with your evening meal.
Magnesium L-Threonate
Magnesium L-Threonate (sold as Magtein®) is the only form shown to reliably cross the blood-brain barrier (a protective filter that controls which substances can pass from the bloodstream into the brain), raising magnesium levels inside the brain directly. A 2024 trial in 80 adults found improvements in both subjective and objective sleep quality after 21 days on 1g per day[⁷]. A 2025 trial in 100 adults found improvements in sleep-related daytime impairment, memory, and cognitive performance after six weeks on 2g per day[⁸]. The evidence is still emerging, but this form has the most direct brain-targeting rationale for sleep. The dose is 1 to 2g per day, taken in the evening.
4. Ashwagandha
Ashwagandha is an adaptogenic herb (one that helps the body adapt to and recover from stress) with a growing body of clinical research. Its active compounds, called withanolides, dampen the stress response and calm the nervous system, making it well suited to sleep disruption driven by ongoing stress or anxiety.
A 2021 meta-analysis in PLOS ONE covering 5 randomised controlled trials and 400 participants found a significant effect on overall sleep, most pronounced in people with a diagnosed insomnia disorder, at doses of at least 600mg per day for at least eight weeks[⁹]. Supporting trials using the KSM-66 extract found significant reductions in time to fall asleep, and morning alertness on rising also improved.
The dose is 300 to 600mg of a standardised root extract containing at least 5% withanolides, taken in the evening. Ashwagandha is contraindicated (not recommended) in pregnancy and should be used with care in autoimmune conditions, thyroid disorders, and by anyone on immunosuppressant medication.
5. Sour Cherry Juice
Sour cherries contain naturally occurring melatonin, tryptophan, and serotonin, all of which contribute to the body's melatonin production. They also contain a compound that blocks an enzyme which normally breaks tryptophan down before it can be converted to melatonin, helping the body reclaim what it would otherwise have lost, particularly in people with higher levels of inflammation.
A 2025 systematic review of seven studies found that 240ml of sour cherry juice twice daily led to significant improvements in sleep duration and efficiency in three studies, and elevated melatonin levels in three others. One included trial reported an average increase in total sleep time of 84 minutes compared to placebo[¹⁰]. An earlier pilot study also found significant reductions in insomnia severity with twice-daily consumption[¹¹].
The evidence is promising rather than conclusive. The natural sugar content is worth noting for anyone managing blood glucose, and a capsule concentrate is a practical alternative.
The Bottom Line
These five supplements share something most sleep products on the market do not: clinical trials testing them in human beings. None of them replace the lifestyle basics, but if good habits are already in place and sleep is still a problem, they are a sensible next step. Start with melatonin or magnesium, give each a genuine trial of four to eight weeks, and reassess from there.
This article is for general education only and does not constitute medical advice. Please speak with your health practitioner before beginning any supplementation, particularly if you are pregnant, have a chronic health condition, or are taking prescription medication.
If you would like to discuss your sleep or how integrative medicine approach can help you - please reach out via the contact page.
References
Cruz-Sanabria F et al. (2024). Dose-response meta-analysis of melatonin for sleep. Journal of Pineal Research. PMID: 38888087
Systematic Review (2025). Melatonin for sleep quality. Journal of Population Therapeutics & Clinical Pharmacology.
Ferracioli-Oda E et al. (2013). Meta-analysis of melatonin for sleep onset latency. PLOS ONE. PMID: 23691095
Baba Y et al. (2025). L-theanine and sleep: systematic review and meta-analysis. Sleep Medicine Reviews. PMID: 40056718
RCT (2025). Magnesium bisglycinate for sleep in adults with self-reported poor sleep. Nature and Science of Sleep. PMC: 12412596
Abbasi B et al. (2012). The effect of magnesium supplementation on primary insomnia in elderly. Journal of Research in Medical Sciences.
Hausenblas HA et al. (2024). Magnesium L-Threonate for sleep: RCT. Sleep Medicine X.
Lopresti AL & Smith SJ et al. (2025). Magtein® for sleep and cognition: RCT. Frontiers in Nutrition. PMID: 41601871
Cheah KL et al. (2021). Effect of ashwagandha on sleep quality: systematic review and meta-analysis. PLOS ONE. PMID: 34559859
Barforoush Z et al. (2025). Tart cherry and sleep: systematic review. Food Science and Nutrition. PMC: 12438961
Pigeon WR et al. (2010). Effects of tart cherry juice on insomnia. Journal of Medicinal Food. PMID: 22038497