What Actually Works for Sleep (It Isn’t Melatonin)
Melatonin is the best-selling sleep supplement in America. In pooled trials it gets people to sleep about seven minutes faster. The behavioural approach that clinical guidelines actually recommend is roughly three times better and works on the part most adults over 50 struggle with, which is not falling asleep but staying asleep.
19 min faster with the behavioural protocol
26 min less time awake at night, behavioural only
88% of melatonin gummies mislabelled
The comparison nobody puts on a label
These numbers come from pooled analyses of randomized trials. They are not close.
| Time to fall asleep | Time awake during the night | |
|---|---|---|
| Cognitive behavioural therapy for insomnia | 19 minutes faster | 26 minutes less |
| Melatonin | 7 minutes faster | No credible effect |
| Magnesium | About 17 minutes faster, weak evidence base | No credible effect |
That second column is the one that matters for most people we work with. The common complaint after 50 is not lying awake at bedtime. It is waking at two in the morning and not getting back down. No supplement in this article has a credible effect on that. The behavioural protocol does, and it is the only intervention in the table with a strong recommendation from the American College of Physicians.
The American Academy of Sleep Medicine goes further and recommends against melatonin, against valerian, and against tryptophan for chronic insomnia.
If you take one thing from this page: the behavioural approach is free, has no side effects, no interactions, and outperforms everything sold in the sleep aisle. Supplements are the accessory, not the offer.
The exercise-timing myth
You have been told not to train in the evening. A pooled analysis of 23 studies found evening exercise did not harm sleep and modestly improved it, including a small increase in deep slow-wave sleep.
The single exception is vigorous exercise finishing within an hour of bedtime, which can delay sleep onset. Everything else is fine. If the only hour you have is 7pm, take it. The training is worth more to your sleep than the hour of buffer is.
Melatonin, honestly
Melatonin is a circadian tool rather than a sedative. It is genuinely useful for jet lag, shift rotation, and a body clock that has drifted late. It is a weak nightly sleeping aid.
Timing beats dose
In a dose-response analysis of 26 trials, when you take it predicted the effect better than how much. The pattern favoured taking it several hours before your target bedtime rather than thirty minutes before. Most people in the United States take it far too late and at far too high a dose.
More is not better, and can be worse
Doses in the 5 to 10 milligram range produce blood levels well above anything your body makes naturally, and melatonin stays active longer in older adults. That produces morning grogginess. In an adult who gets up in the night, grogginess is a fall risk, which is a materially different problem than not sleeping well. Lower doses in the 0.5 to 1 milligram range approximate normal physiology.
The label problem is severe
This is the part of the category that should give anyone pause.
- An analysis of 31 melatonin products found actual content ranging from 83 percent below to 478 percent above the label. More than 71 percent missed the label by more than 10 percent. Batch-to-batch variation within a single product reached 465 percent. Serotonin was detected in 8 of the 31 products.
- A 2023 analysis of 25 melatonin gummy brands found 88 percent were inaccurately labelled. One contained no detectable melatonin at all and 31 milligrams of CBD instead.
If you buy melatonin, buy a third-party verified product. In a category with an 88 percent mislabelling rate, verification is not a premium feature. It is the entire difference between a dose and a guess.
What we do and do not stock
| Magnesium glycinate | Stocked. Pooled trials in older adults show faster sleep onset. The evidence base is small and the trials used other magnesium forms, so we sell it on tolerability and repletion rather than on a claim that glycinate is “the sleep form”, which is a marketing line with no direct trial support. |
|---|---|
| L-theanine 200 mg | Stocked. Improves subjective sleep quality and next-day function. The effect on how fast you fall asleep is close to a rounding error. Best safety profile of anything here, with no sedation and no next-day impairment. |
| Glycine 3 g | Stocked. The only ingredient here with human data showing improved next-day psychomotor performance. We stock it while saying plainly that every human trial came from one company, with about a dozen participants each, and nobody has independently replicated it. |
| Valerian | Not stocked. Across 14 trials in 1,602 people it beat placebo on none of thirteen measures of efficacy, while producing more adverse events than placebo. |
| Oral GABA | Not stocked. Reviews find very limited evidence, and no human study shows oral GABA meaningfully raises GABA in the brain. The mechanism on the label does not occur in the body. |
| 5-HTP | Not stocked, at any dose. It is a direct serotonin precursor. Roughly one in six adults aged 40 to 70 takes a serotonergic medication such as an SSRI, SNRI, tramadol or a triptan, and the combination carries a real risk of serotonin syndrome. |
| Ashwagandha | Not stocked. Published case series document liver injury, including transplants and deaths, mostly in people with pre-existing liver disease they often did not know they had. |
When to stop reading and see your physician
Some sleep problems are medical problems, and no supplement touches them. In one trial screening volunteers for insomnia, three of eleven people were found to have undiagnosed sleep apnea and had to be referred out.
- Loud snoring, gasping or choking awakenings, or a partner who has seen you stop breathing
- Waking unrefreshed after seven or eight hours, morning headaches, or falling asleep during the day
- Difficulty sleeping at least three nights a week for three months or more
- A recent or sudden change in your sleep, which can be a first sign of several treatable conditions
- Creeping or restless sensations in the legs, or acting out dreams
- Sleep disruption alongside low mood or loss of interest in things you used to enjoy
- Any fall in the past twelve months, in which case nothing sedating belongs in the picture
Redefine Fitness does not diagnose or treat sleep disorders. If any of the above describes you, that is a conversation for your physician and it is a more valuable one than anything on a supplement shelf.
We would rather you sleep well than buy something. This is what we build programs around every day. Every session at Redefine is one-on-one with a Fitness Specialist who builds around your history, your clearances, and what your clinicians have told you.
See the Sleep Support collection → · The full refusal list → · Is creatine safe after 50? · Do BCAAs actually work?
This article is educational and is not medical advice. Redefine Fitness does not diagnose, treat, or prescribe, and does not treat insomnia or any sleep disorder. These statements have not been evaluated by the Food and Drug Administration. Products referenced are not intended to diagnose, treat, cure, or prevent any disease. Talk to your physician or pharmacist before starting any supplement, particularly if you take prescription medication or a sedative. Redefine Fitness operates a practitioner dispensary and earns a margin on products purchased through it; see our full disclosure.