A handful of supplements have genuine evidence behind them for improving sleep, with melatonin, magnesium, glycine, and chamomile extract leading the pack. None of them work like a sleeping pill, but each targets a different piece of the sleep puzzle, from helping you fall asleep faster to keeping your body temperature in the right zone through the night.
Melatonin: The Most Studied Option
Melatonin is the supplement most people reach for first, and it has the most research behind it. Your brain naturally produces melatonin as darkness falls, signaling that it’s time to wind down. A supplement simply adds to that signal, which is why it works best for people whose natural melatonin timing is off, such as shift workers, jet-lagged travelers, or anyone whose sleep schedule has drifted later than they’d like.
For short-term insomnia, a 2mg slow-release tablet taken one to two hours before bed is a standard starting point. For ongoing sleep problems, the same dose taken 30 minutes to an hour before bed is typical. More isn’t necessarily better. Many over-the-counter products sell 5mg or 10mg tablets, but starting low gives you room to adjust without overshooting.
One important caveat: in the U.S., melatonin is classified as a dietary supplement, not a medication, so it doesn’t go through the same quality checks. One study found that the actual melatonin content in supplements ranged from less than half to more than four times the amount stated on the label. Chewable tablets, the form children are most likely to take, had the widest variability. Some products even contained compounds that normally require a prescription. If accuracy matters to you (and it should), look for products carrying the USP Verified Mark, which confirms the bottle contains what it claims.
Magnesium: Calming the Nervous System
Magnesium supports sleep through two pathways. First, it helps maintain the balance between excitatory and calming neurotransmitters in your brain. When magnesium levels are adequate, your nervous system can shift into a more relaxed state at night. Second, magnesium plays a role in your body’s own melatonin production, so being low on it can quietly undermine your sleep-wake cycle even if everything else is in order.
The form you choose matters. Magnesium citrate has the most evidence supporting it as a sleep aid, but it also has a strong laxative effect. Unless constipation is part of your picture, magnesium glycinate is gentler on the gut and absorbs well. Magnesium oxide is another option that costs less, though it’s not absorbed quite as efficiently. Skip the topical sprays and gels. Absorption through the skin is low enough that sleep researchers don’t recommend them.
The NIH sets the upper tolerable limit for supplemental magnesium at 350mg per day for adults. Go above that and you’re likely to get diarrhea, nausea, or cramping. That limit applies only to supplements, not to magnesium from food, so eating magnesium-rich foods like nuts, seeds, and dark leafy greens on top of a supplement is fine. Most people taking magnesium for sleep use somewhere between 200mg and 350mg in the evening.
Glycine: Lowering Your Core Temperature
Glycine is an amino acid that works through a mechanism most people don’t expect: it helps drop your core body temperature. Your body naturally cools down as you fall asleep, and glycine accelerates that process by increasing blood flow to your hands and feet, which radiates heat away from your core. Thermal imaging studies show this effect kicks in within about 30 minutes of taking it.
The effective dose in research is 3 grams, taken about an hour before bed. Smaller amounts are less effective. In one study of people with ongoing sleep difficulties, 3 grams of glycine reduced the time it took to fall asleep and improved how rested participants felt the next morning. Across multiple studies, people report falling asleep more easily, sleeping more soundly, and waking up more refreshed. Glycine is naturally present in bone broth, meat, and fish, and it’s generally well tolerated as a supplement since your body already uses it for dozens of other processes.
Chamomile and Apigenin
Chamomile tea before bed is one of the oldest sleep remedies, and the active compound behind it is apigenin, a flavonoid found in high concentrations in chamomile flowers. Apigenin binds to the same brain receptors that anti-anxiety medications target, but with much weaker potency. The result is a mild calming effect that can reduce the mental alertness keeping you awake, without heavy sedation or grogginess.
Early research also suggests apigenin may help normalize elevated cortisol levels, your body’s main stress hormone, which can interfere with both falling and staying asleep. You can get apigenin from chamomile tea, though concentrated chamomile extract supplements deliver a higher and more consistent dose. If you enjoy the ritual of tea before bed, that’s a perfectly reasonable way to get it. The warmth and routine add their own sleep-promoting effects.
Tart Cherry Juice
Tart cherry juice contains small amounts of both melatonin and tryptophan, the amino acid your body converts into melatonin and serotonin. Every 100 grams of tart cherries provides about 9 milligrams of tryptophan and roughly 0.135 micrograms of melatonin. Those numbers are modest, and tart cherry juice is unlikely to rival a melatonin supplement for potency. But some people notice a benefit, possibly because the combination of tryptophan, melatonin, and anti-inflammatory compounds in the juice works together in ways a single-ingredient supplement doesn’t. If you try it, use tart (Montmorency) cherries specifically, not sweet cherry varieties, and watch the sugar content in commercial juices.
What to Watch Out For
Sleep supplements are generally low-risk for healthy adults, but they aren’t risk-free. Melatonin can interact with blood thinners, and the Cleveland Clinic lists it among the supplements people on anticoagulants should avoid without medical guidance. The same applies to several herbal supplements sometimes marketed for relaxation, including St. John’s Wort and ginkgo biloba.
For children, the American Academy of Sleep Medicine urges caution with melatonin specifically. Calls to poison control centers and emergency room visits related to melatonin overdose in children have increased sharply in recent years. The labeling inconsistencies mentioned earlier make this especially concerning for pediatric use, since a chewable tablet labeled 3mg could easily contain much more. Many childhood sleep problems respond better to changes in bedtime routines, screen habits, and schedules than to supplements.
Combining Supplements Strategically
Because these supplements work through different mechanisms, some people stack two or three of them. Magnesium plus glycine is a common pairing: magnesium calms neural activity while glycine drops core temperature. Adding low-dose melatonin on top can reinforce your body’s sleep timing signal. There’s no strong clinical data on specific combinations, but since each operates on a distinct pathway, the logic is reasonable and the risk of interaction between them is low.
Start with one supplement at a time so you can tell what’s actually helping. Give each one at least a week or two before judging its effect, since some benefits, particularly with magnesium, build as your levels normalize. If a single supplement gets you 80% of the way there, adding a second may not be worth the cost or complexity.