The most effective options for helping you fall asleep range from melatonin and magnesium supplements to over-the-counter antihistamines and herbal extracts like valerian root. What works best depends on whether you need occasional help drifting off or a longer-term solution for poor sleep quality. Here’s what the evidence says about each option and how to use them safely.
Melatonin: The Most Popular Choice
Melatonin is your brain’s own sleep-timing signal, and supplemental melatonin works best for resetting your internal clock rather than knocking you out. It’s most useful when your sleep schedule is off, whether from jet lag, shift work, or a habit of staying up too late. Johns Hopkins Medicine recommends taking 1 to 3 milligrams about two hours before bedtime. Starting low matters because more isn’t better with melatonin. Higher doses can actually make sleep worse by disrupting your natural rhythm.
One significant concern: what’s on the label often isn’t what’s in the bottle. A 2023 study tested 25 over-the-counter melatonin gummies and found 22 of them were inaccurately labeled. The actual melatonin content ranged from 74% to 347% of what was listed, meaning some products contained nearly 3.5 times the stated dose. Most had more melatonin than advertised, typically 1.2 to 1.7 times the labeled amount. One product contained no detectable melatonin at all. About 26% of supplements tested in a separate study also contained serotonin, a hormone that can cause harmful effects even in small amounts. Choosing products with third-party testing (look for USP or NSF certification) reduces this risk.
Caffeine also changes how melatonin works in your body. In one study, a single large cup of coffee increased melatonin’s blood levels by 137%. If you drink coffee in the afternoon and take melatonin at night, you may be getting a much stronger effect than intended.
Magnesium for Relaxation
Magnesium helps activate your body’s calming nervous system and plays a role in regulating the brain chemicals involved in winding down. Many people are mildly deficient without knowing it, and that deficiency can contribute to restlessness and difficulty falling asleep. Magnesium glycinate is the form most commonly recommended for sleep because it’s well absorbed and less likely to cause digestive issues than other forms like magnesium citrate or oxide.
Typical doses range from 200 to 400 milligrams taken about 30 to 60 minutes before bed. The effects tend to be subtle, working more as a general relaxation aid than a direct sleep inducer. It’s one of the safer long-term options, though taking too much can cause loose stools.
Valerian Root and L-Theanine
Valerian root has stronger clinical evidence behind it than most herbal sleep aids. A meta-analysis of 18 randomized controlled trials found that valerian significantly reduced the time it took people to fall asleep and improved overall sleep quality compared to placebo. It works gradually, so taking it for a week or two before judging results is reasonable. Most studies use doses between 300 and 600 milligrams taken 30 minutes to two hours before bed. The smell and taste are notably strong and unpleasant, which is why capsules are the preferred form.
L-theanine, an amino acid found naturally in tea, takes a different approach. Rather than making you drowsy, it promotes a relaxed mental state that makes falling asleep easier. Evidence from randomized trials suggests it can improve sleep quality, sleep duration, and how well people function the next day, particularly when combined with GABA (another calming brain chemical available as a supplement). Typical doses are 200 to 400 milligrams. L-theanine is a good option if racing thoughts keep you up, since it specifically targets mental restlessness.
Chamomile: More Than a Warm Drink
Chamomile contains a compound called apigenin that binds to the same brain receptors targeted by prescription anti-anxiety medications, just far more gently. A cup of chamomile tea provides a mild calming effect, but the concentrations used in clinical research are higher. In one trial, elderly participants who took 200 milligrams of chamomile extract twice daily for 28 days experienced meaningful improvements in sleep quality. If you enjoy the ritual of tea before bed, chamomile is a reasonable addition. For a stronger effect, standardized chamomile extract capsules deliver a more consistent dose.
Over-the-Counter Antihistamines
The active ingredients in most drugstore sleep aids (products like ZzzQuil, Unisom, or store-brand equivalents) are antihistamines: either diphenhydramine or doxylamine. Both work by lowering histamine levels in your brain, which is part of how your brain naturally prepares for sleep. They’re effective for occasional use, such as after a stressful day or during travel.
These are not meant for regular use, and the side effects matter. Both cause next-day grogginess, dry mouth, constipation, difficulty urinating, and blurred vision. More seriously, because they block a key nervous system chemical called acetylcholine, long-term use carries risks. A 2018 study found that regular use of these types of medications increased dementia risk for up to 20 years after exposure. For a rough night here and there, they work. As a nightly habit, they’re a poor choice.
Mixing antihistamine sleep aids with melatonin amplifies sedation and can impair your alertness, judgment, and breathing, especially if you’re older. If you’re considering combining anything, keep it to gentler pairings like magnesium with melatonin or magnesium with L-theanine.
What Actually Works Long-Term
The American Academy of Sleep Medicine’s most recent guideline is clear: cognitive behavioral therapy for insomnia (CBT-I) is the most effective first-line treatment for ongoing sleep problems. It outperforms medication alone, and adding medication to CBT-I provides only modest additional benefit for certain outcomes like total sleep time. The guideline specifically recommends against combining medication with CBT-I when behavioral treatment alone is working, because the added risks of pharmacotherapy aren’t justified.
CBT-I isn’t a pill. It’s a structured program, typically four to eight sessions, that retrains your sleep habits and addresses the thought patterns keeping you awake. It’s available through therapists, sleep clinics, and now several digital apps. The improvements tend to last long after the program ends, which no supplement or medication can claim.
For the occasional rough night, melatonin (1 to 3 milligrams, two hours before bed) or magnesium glycinate (200 to 400 milligrams) are the safest starting points. Valerian root and L-theanine offer additional options with reasonable evidence. Antihistamine sleep aids are a last resort for truly occasional use. If you find yourself reaching for something every night, the problem is almost certainly better addressed through your sleep habits than your medicine cabinet.