What you eat, drink and take, and how it affects sleep.

• Caffeine: in a controlled study, 400 mg of caffeine taken even 6 hours before bed reduced total sleep by more than an hour. Try a caffeine cut-off at least 6 hours before bedtime (many people do better with a noon cut-off). Remember tea, cola, energy drinks, pre-workout and dark chocolate.
• Alcohol: it can make you fall asleep faster, but a review of the research found it disrupts sleep in the second half of the night and reduces REM sleep, with bigger effects at higher doses. Avoid using a “nightcap” as a sleep aid and leave a few hours between your last drink and bed.
• Meals: avoid large, heavy or spicy meals right before bed, especially if you get reflux; a light snack is fine if hunger keeps you up.
• Fluids: taper drinks in the last hour or two if you wake to use the bathroom.
• Consistency beats supplements: a regular wake time, morning daylight and a cool, dark bedroom do more for most people than any pill.

Sources: Drake et al., J Clin Sleep Med 2013 (caffeine 0, 3 or 6 h before bed); Ebrahim et al., Alcohol Clin Exp Res 2013 (alcohol and sleep review)

Magnesium is an essential mineral, and many adults get less than recommended from food. For sleep specifically, NIH’s NCCIH says the evidence is limited and of low quality. Glycinate (bisglycinate) forms are popular because they are generally gentler on the stomach than oxide or citrate.

• Food first: leafy greens, legumes, nuts, seeds and whole grains.
• The upper limit for supplemental magnesium in adults is 350 mg/day unless a clinician advises otherwise. Too much can cause diarrhoea and cramping.
• Ask a doctor first if you have kidney disease, or take antibiotics, bisphosphonates, diuretics or acid-reducing drugs, because magnesium can interact with them.

Sources: NIH Office of Dietary Supplements: Magnesium fact sheet; NCCIH: Sleep disorders and complementary health approaches

Melatonin is a hormone that signals “night” to your body clock. It is most useful for shifting sleep timing (jet lag, delayed sleep phase), not as a nightly sedative. The American Academy of Sleep Medicine’s insomnia guideline suggests against melatonin for chronic insomnia in adults.

• More is not better: many sleep clinicians start with 0.5–1 mg, taken a few hours or 30–60 minutes before your target bedtime depending on the goal. Ask your doctor what dose and timing fit you.
• In the U.S. melatonin is sold as a supplement, and tested products have contained very different amounts than their labels state. Choose a manufacturer that tests its products and documents it, and ask your provider which one to use.
• Children and teens: the AASM advises talking to a pediatric clinician before giving melatonin; melatonin overdoses in children have risen sharply.
• Ask a doctor first if you are pregnant or breastfeeding, have epilepsy or an autoimmune condition, or take blood thinners, blood-pressure, diabetes or immune-suppressing medicines.

Low-dose options: the practitioner products below come in 0.5 mg and 1.5 mg servings. Your provider can tell you which dose and timing suit your goal.

Sources: NCCIH: Melatonin, what you need to know; AASM health advisory: melatonin use in children and adolescents; Rishi et al., J Clin Sleep Med 2023; Sateia et al., AASM insomnia pharmacologic guideline, J Clin Sleep Med 2017

Tart (Montmorency) cherries contain small amounts of melatonin and polyphenols. A small pilot study in 15 older adults with insomnia found modest improvements with tart cherry juice twice daily versus placebo. Promising, but the studies are small. Watch the sugar and calories in juice, and ask a doctor if you have diabetes or take blood thinners.

No practitioner pick yet: we did not find a tart-cherry product for sleep from the practitioner brands we cover (Biotics Research, Standard Process, Metagenics, Designs for Health, Xymogen, Pure Encapsulations, Integrative Therapeutics, Ortho Molecular). Practitioner cherry products we found are either sweet cherry or formulated for other purposes. Whole tart cherries or 100% tart cherry juice are a food option; ask your provider, especially if you have diabetes.

Sources: Pigeon et al., J Med Food 2010

Glycine is an amino acid. Small Japanese studies found 3 g before bed improved how rested people felt and slightly shortened the time to fall asleep. The evidence comes from few, small trials. Ask a doctor first if you take clozapine or other antipsychotics.

Sources: Yamadera et al., Sleep and Biological Rhythms 2007

L-theanine is an amino acid found in tea. A 2025 systematic review and meta-analysis found small improvements in some sleep measures, with mixed results across studies. It may suit people whose sleep is disturbed by a busy mind. Ask a doctor first if you take blood-pressure medicines or stimulants.

Sources: Bulman et al., Sleep Med Rev 2025 (PubMed 40056718)

Practitioners often use combination formulas. Their individual ingredients have mixed evidence (melatonin and L-theanine above; valerian and passionflower have small, inconsistent studies), and the combined products themselves have generally not been tested in large trials. Herbal sedatives can add to the effects of alcohol, sleep medicines and some antidepressants, so check with your provider and pharmacist.