Ask five people how to sleep better and you’ll get five confident, contradictory answers: cut caffeine after noon, sleep in a colder room, try melatonin, download a sleep-tracking app, never look at a screen after 9 p.m. Some of that holds up. Some of it barely does. Almost none of it comes with any indication of which is which.
That distinction actually exists in the research, even if it rarely survives the trip into a listicle. Sleep science has a reasonably clear hierarchy of what helps, what probably helps a little, and what’s mostly folklore that sounds sensible. It’s worth knowing before you rearrange your evening around advice that hasn’t earned it.
How much sleep you actually need
The starting point is less complicated than the endless “optimal sleep hack” content suggests. The Centers for Disease Control and Prevention recommends at least seven hours a night for adults aged 18 to 60, with slightly narrower ranges — seven to nine hours, then seven to eight — for older age brackets. That’s it. Not eight hours exactly, not a number that shifts by season or occupation. At least seven.
Despite how unambiguous that guidance is, the CDC estimates that roughly one in three American adults falls short of it on a regular basis — a gap wide enough that “get more sleep” is arguably still the single highest-leverage piece of health advice most people ignore, well before anything more specific.
What has strong evidence: CBT-I
If you asked a sleep specialist for the one intervention with the most solid evidence behind it, it wouldn’t be a supplement or a gadget. It would be cognitive behavioral therapy for insomnia, or CBT-I — a structured, typically four-to-eight-session program that combines practical sleep-scheduling techniques with addressing the anxious thought patterns that build up around not sleeping.
The American Academy of Sleep Medicine’s clinical guideline gives CBT-I its strongest possible recommendation as the first-line treatment for chronic insomnia, ahead of medication rather than alongside it as an equal option. The guideline’s lead author put it plainly: it’s “the most supported therapy” once you actually review the trial evidence using standard methodology. The NHS reaches the same conclusion, recommending CBT-I as the first thing to try before medication, and it’s increasingly delivered online rather than requiring an in-person specialist.
The behavioral techniques inside CBT-I are also the closest thing sleep science has to universally agreed-upon advice: a consistent wake time — more important than a consistent bedtime, which is harder to control — a dark and reasonably cool bedroom, keeping caffeine out of the second half of your day, and the one everyone already knows and mostly ignores anyway: putting the phone down before bed, since screen light in the evening pushes your body’s sense of “not yet” later than it needs to be.
A consistent wake time is also the piece of advice that’s gotten harder to follow for a lot of people. If your work schedule has gone from a fixed office routine to something looser and more self-directed under hybrid arrangements, an inconsistent wake time is one of the more overlooked casualties of a flexible week — flexibility that helps in most ways can quietly work against you here.
What has weaker, more situational evidence: melatonin
Melatonin supplements are probably the most-purchased sleep aid that also has the most misunderstood evidence base. The research picture, according to the National Institutes of Health’s National Center for Complementary and Integrative Health, is genuinely mixed rather than simply negative.
For general, garden-variety insomnia, the evidence is thin enough that two major clinical guidelines have specifically recommended against using melatonin as a treatment. Where it performs more credibly is in narrower situations: shifting your sleep-wake timing, such as with jet lag or shift work, or delayed sleep-wake phase disorder, a condition where your body clock is persistently out of sync with when you need to be up. In one trial for that specific condition, melatonin combined with a consistent bedtime routine helped people fall asleep roughly half an hour earlier than they otherwise would have.
In other words, melatonin isn’t fraudulent, but it’s also not really a treatment for “I have trouble sleeping” in the way it’s marketed. It’s a fairly specific tool for timing problems, with modest evidence even there, and short-term use appears safe for most adults — though its long-term safety hasn’t been well established, which matters given how casually it’s often taken.
What’s mostly folklore
A lot of the advice that circulates confidently — a nightcap to help you drift off, a heavy meal to make you drowsy, “just try harder to relax” — either isn’t supported by the research or actively works against you. Alcohol is well known to fragment sleep in its second half even though it can make falling asleep faster. Clock-watching when you can’t sleep, which feels like a natural response to insomnia, is specifically flagged in sleep guidance as something that makes the anxiety, and therefore the insomnia, worse rather than better.
None of that is dramatic or new information. But it’s a useful reminder that “sounds like it should work” and “is supported by evidence” are different bars, and a lot of popular sleep advice only clears the first one.
When to stop managing it yourself
If none of this moves the needle after a few weeks of consistent effort, that’s the point where the guidance shifts from “try these things” to “talk to a doctor.” Persistent insomnia can be a symptom of something else — a sleep disorder like sleep apnea, a mental health condition, a medication side effect — and self-directed sleep hygiene isn’t designed to diagnose any of that.
The research above is a solid starting point, not a substitute for someone actually looking at your specific situation. It’s also a reasonable filter for the next sleep tip that lands in your feed: ask which category it falls into before you rearrange your night around it.
