The 5 Best Supplements for Sleep in Australia (2026)

Unlike the US where melatonin is sold over the counter in every pharmacy and supermarket, melatonin is a Schedule 4 (prescription-only) substance in Australia under the TGA. The only exception is low-dose (2mg or less) prolonged-release melatonin (brand name Circadin) for adults over 55 — which was recently reclassified to Schedule 3 (pharmacist-only).

This means if you're under 55, you need a doctor's prescription for melatonin. This is actually a more cautious approach than most countries, and it's worth understanding why: melatonin is a hormone, and the TGA treats hormone supplementation more conservatively.

The good news is that several non-hormonal supplements have genuine evidence for sleep improvement.

Evidence level: Moderate (multiple RCTs)

Typical dose: 200–400 mg elemental magnesium, 30–60 min before bed

Magnesium glycinate combines two sleep-supporting compounds. The magnesium acts on GABA receptors and reduces cortisol, while glycine independently lowers core body temperature and promotes sleep onset.

A 2012 RCT showed 500 mg magnesium for 8 weeks significantly improved sleep time, sleep efficiency, and melatonin levels in elderly adults with insomnia. The glycinate form is preferred for sleep because of glycine's additional calming effects and superior absorption compared to oxide.

Australian availability: Widely available from Chemist Warehouse, iHerb AU, Amazon AU. Brands like Herbs of Gold and Bioceuticals stock glycinate-specific formulas.

Evidence level: Moderate (multiple RCTs)

Typical dose: 200–400 mg, 30–60 min before bed

L-Theanine, an amino acid found naturally in green tea, promotes alpha brain wave activity — the same pattern seen during meditation. A 2019 RCT in Acta Neuropsychiatrica studied 30 healthy adults and found 200 mg/day of L-theanine for 4 weeks significantly improved sleep quality scores (PSQI) compared to placebo.

A notable benefit: L-theanine doesn't cause next-day drowsiness. It reduces anxiety and "racing mind" at bedtime without sedation. A 2011 study in the Journal of Functional Foods confirmed it reduced resting heart rate, suggesting genuine physiological relaxation.

Australian availability: Available OTC at Chemist Warehouse, health food stores, and online. Often combined with magnesium in sleep formulas.

Evidence level: Mixed (many trials, inconsistent results)

Typical dose: 300–600 mg standardised extract, 30 min before bed

Valerian has been used for sleep since Ancient Greece, and it's one of the most-studied herbal sleep aids. However, the evidence is frustratingly inconsistent. A 2006 meta-analysis in Sleep Medicine Reviews of 16 RCTs concluded valerian might improve subjective sleep quality, but the studies were too heterogeneous for firm conclusions.

A more recent 2020 systematic review in Journal of Evidence-Based Integrative Medicine covering 60 studies found that valerian showed promise for sleep improvement, particularly when combined with hops extract.

The issue is standardisation — valerian products vary enormously in active compound concentration (valerenic acid), which likely explains the mixed results.

Australian availability: Widely available as a listed medicine. Blackmores, Swisse, and Nature's Own all carry valerian products. Look for products standardised to valerenic acid content.

Evidence level: Preliminary (small RCTs)

Typical dose: 480 ml tart cherry juice or equivalent extract, twice daily

Tart cherries (Montmorency variety) contain small amounts of naturally occurring melatonin plus proanthocyanidins that inhibit tryptophan degradation, potentially increasing serotonin availability.

A 2012 pilot study in the European Journal of Nutrition found that tart cherry juice increased melatonin levels and improved sleep duration and quality in 20 volunteers. A 2018 RCT in the American Journal of Therapeutics showed that 8 oz of tart cherry juice twice daily for 2 weeks increased sleep time by 84 minutes in adults with insomnia.

The caveat: these are small studies, and juice-based supplementation means significant sugar intake. Extract capsules are a lower-calorie alternative but less studied.

Australian availability: Tart cherry extract capsules available on iHerb AU and Amazon AU. Juice concentrates available at health food stores.

Evidence level: Preliminary (limited but promising RCTs)

Typical dose: 3 g, taken before bed

Glycine is a simple amino acid that acts as an inhibitory neurotransmitter and lowers core body temperature — a key trigger for sleep onset. A 2006 study in Sleep and Biological Rhythms found that 3 g of glycine before bed improved subjective sleep quality and reduced daytime sleepiness in participants with poor sleep.

A 2007 follow-up study published in Neuropsychopharmacology confirmed that glycine improved sleep quality in people with insomnia, with polysomnography showing faster time to slow-wave sleep (the most restorative phase).

This is why magnesium glycinate does double duty — you get both magnesium and glycine in one supplement.

Australian availability: Pure glycine powder available from bulk supplement retailers and Amazon AU. Very affordable.

Diphenhydramine/doxylamine (Restavit, Unisom): These are antihistamines marketed as sleep aids. While effective short-term, they impair sleep architecture (reducing REM sleep), cause next-day grogginess, and are associated with increased dementia risk in long-term users per a 2015 study in JAMA Internal Medicine.

High-dose CBD: Evidence for CBD and sleep is still very preliminary and inconsistent. Australian access requires a prescription via the Special Access Scheme, and quality control varies significantly between products.