CBD Oil and Insomnia: What the Research Says About Falling Asleep

People try CBD for insomnia hoping it will get them to sleep faster, and the honest answer is that the human evidence is thin, mixed and drawn mostly from small studies. CBD is not a sleeping pill and it is not a treatment for insomnia. Some people report falling asleep with less effort when they take it in the evening. Others notice nothing at all.

This article is for anyone who has been lying awake and is weighing CBD up. It covers what insomnia actually is, why the type you have matters, what the research on sleep onset found, and when to stop experimenting and speak to your GP. For how cannabinoids relate to the sleep cycle generally, our guide to CBD and sleep sets out the mechanism in full.

What insomnia actually is

Insomnia is not simply a bad night, and it is not the same as choosing to stay up late. The clinical definition has a specific shape: difficulty falling asleep or staying asleep, despite having adequate opportunity to sleep, that causes a problem during the day. That last part matters. If you sleep six hours and feel fine, you do not have insomnia. If you spend eight hours in bed, sleep five of them and feel wrecked, you might. Sleep researchers separate it along two axes, and knowing where you sit on both is more useful than any supplement decision.

Acute versus chronic insomnia

• Acute, or short-term, insomnia. Days or weeks, usually with an obvious trigger: a deadline, a bereavement, a new baby, jet lag, an illness. It typically resolves once the trigger passes.
• Chronic insomnia. Sleep difficulty on at least three nights a week for three months or longer. By this point the original trigger is often long gone, and the problem is being maintained by other things, such as spending longer in bed to compensate, or the anxiety that builds around bedtime itself.

This distinction changes what is worth trying. A rough fortnight is a very different situation from six months, and the second one deserves a proper assessment rather than another supplement.

Sleep-onset versus sleep-maintenance insomnia

• Sleep-onset insomnia. You cannot fall asleep. You get into bed and lie there for 45 minutes or more with your mind running. This is the type most people mean when they search for CBD and sleep onset, and it is often linked to a mind that will not settle or a body clock running later than your alarm.
• Sleep-maintenance insomnia. You fall asleep normally and then wake in the night, unable to get back down. Common contributors include evening alcohol, sleep apnoea, pain and hormonal changes.
• Early morning waking. Waking at four or five and being unable to return to sleep. Worth mentioning to your GP, because it can accompany low mood.

Most CBD interest sits with the first type. If your problem is waking at three every night rather than getting to sleep, a cannabinoid is unlikely to be the answer and the cause is worth investigating.

Why people try CBD for insomnia

The appeal is mostly about what people want to avoid. Prescription sleep medication brings next-day grogginess and, in some cases, tolerance. Over-the-counter antihistamine sleep aids leave many people feeling heavy the following morning. CBD is available without a prescription, is not intoxicating, and has not been shown to produce dependence in the way sedative hypnotics can. It is also worth separating from cannabis generally: THC is the compound with psychoactive properties, and CBD is non-intoxicating, so people who take it during the day do not typically describe feeling sedated.

The other reason is that a lot of sleep-onset insomnia is not really a sleep problem. It is an arousal problem that shows up at bedtime. As Leslie Korn, PhD, has put it, “Stress triggers a cascade of physical reactions that affect immune function, our hormones, cognitive function, and our internal clock, known as our circadian rhythm.” CBD is not classified as an adaptogen, though it is often compared to one, because people describe taking the edge off rather than being knocked out.

What the research says about CBD and sleep onset

There is research here, but it is a long way from settled. One of the earliest human studies appeared in the Journal of Clinical Pharmacology in 1981. It gave 160 mg of CBD to a small group of people with insomnia and reported longer self-reported sleep duration than placebo. It is cited constantly, and it involved fewer than 20 participants at an amount far above what most commercial products contain.

The study quoted most often now is a 2019 case series in The Permanente Journal, in which 72 adults with anxiety and poor sleep took 25 mg of CBD and completed assessments after a month. Sleep scores rose in 66% of them. It was retrospective, had no placebo group, and ran at a single clinic alongside ongoing clinical care, so the change cannot be attributed to CBD with any confidence.

Read across the field and a few patterns stand out:

• Most trials are small, often under 100 people, and short.
• Doses range from 25 mg to several hundred milligrams, which makes results hard to compare.
• Placebo groups frequently change too, which is why uncontrolled studies are weak evidence.
• Much of the work recruited people with anxiety rather than diagnosed insomnia, so it is unclear whether CBD acted on sleep or on something interfering with it.
• Almost nothing measures sleep objectively. Most of it relies on questionnaires.

The reasonable summary is that a mechanism is plausible, some people report something, and the evidence does not support promising anyone a result.

CBD, CBN and melatonin compared

These three get compared constantly and they are not the same kind of thing. Melatonin is a hormone your body already makes, and in the UK it is a prescription-only medicine rather than something on a shop shelf. CBD and CBN are plant cannabinoids sold as food supplements.

The important point about melatonin is that it is a timing signal, not a sedative. Clinical guidance does not generally recommend it as a treatment for chronic insomnia in adults, which is not the same as saying it is useless. Its role is mostly circadian. If your sleep is late rather than short, our article on the circadian rhythm and how to reset your body clock is the more relevant read.

How CBD is sold in the UK

Worth a paragraph, because it is not the same here as it is in the United States. Ingestible CBD is treated in the UK as a novel food, and a CBD oil, capsule or edible has to be on the Food Standards Agency public list to be sold legally in England and Wales. UK rules also cap controlled substances at a very low level per container. None of that makes CBD a sleep product: it is sold as a food supplement, and no UK seller is permitted to claim it treats insomnia. Check that a brand can point you to its place on the FSA list and to a batch lab report that matches the bottle you are holding.

How much people take, and when

There is no established dose of CBD for insomnia, and nobody should hand you one as though it were a prescription. Studies have used anything from 25 mg to several hundred milligrams. Most people find their own level, and it is usually lower than they expected. The general approach:

• Start at the low end of the serving size printed on the product you bought.
• Stay there for several nights before changing anything. One night tells you nothing.
• Adjust in small steps rather than doubling.
• Note the amount, the time and how the night went. Memory is unreliable about sleep.
• More is not automatically better. Plenty of people settle on less than they started with.

Format changes both onset and absorption. Held under the tongue for 60 to 120 seconds, CBD oil is absorbed through the tissue in the mouth, with an absorption rate in the region of 13% to 19%, and most people take it 30 to 60 minutes before bed. CBD capsules and edibles pass through digestion first, so allow 60 to 90 minutes. Taking either with some fat in your stomach generally means more is absorbed.

If you take prescription medication, speak to your GP or pharmacist first, because CBD can affect how some medicines are processed by the liver.

What CBD will not do

• It will not knock you out. CBD does not act like a sedative hypnotic. If you expect the heaviness of a sleeping tablet, you will conclude it did nothing.
• It will not move a body clock. If you naturally fall asleep at 2am and force yourself up at 6am, that is a timing problem and no cannabinoid will shift it.
• It will not treat an underlying cause. Sleep apnoea, restless legs, chronic pain, thyroid problems, medication side effects and depression all disrupt sleep, and all need identifying rather than covering over.
• It will not replace behavioural treatment. For chronic insomnia the best-supported approach is cognitive behavioural therapy, not a supplement.
• It will not work on night one for most people. Give it two consistent weeks, and expect something subtle rather than dramatic.

When to see your GP instead

There is a point at which experimenting with products stops being reasonable. Book an appointment if any of the following apply.

• Sleep difficulty on most nights for three months or more.
• Loud snoring, gasping, or someone has told you that you stop breathing in your sleep.
• Falling asleep during the day, especially while driving.
• Uncomfortable leg sensations at night that ease when you move.
• Waking very early alongside persistently low mood.
• Sleep that got worse after starting a new medication.

It is worth knowing what a GP is likely to suggest, because it is usually not a prescription. Cognitive behavioural therapy for insomnia, shortened to CBT-I, is the recommended first-line approach for chronic insomnia in adults, ahead of medication. It is available as a structured digital programme as well as face to face, and its results tend to hold up after treatment ends in a way medication does not. CBD is not a substitute for it.

Frequently asked questions about CBD and insomnia

Does CBD work for insomnia?

Some people report falling asleep more easily when they take CBD in the evening, but the research is limited, mostly uncontrolled, and often studies people with anxiety rather than diagnosed insomnia. CBD is not a treatment for insomnia, and it will not address an underlying cause such as sleep apnoea.

How much CBD oil should I take for insomnia?

There is no established amount. Studies have used 25 mg to several hundred milligrams, and responses vary widely with body weight, metabolism and format. Most people start at the low end of the product’s serving size, hold it for several nights, then adjust in small increments while keeping a written record.

Is CBD or melatonin better for insomnia?

They do different jobs, and in the UK melatonin is prescription only. Melatonin is a timing signal, best supported for circadian problems such as jet lag or a late-running body clock. CBD is more often taken as part of an evening routine. Neither is a recognised treatment for chronic insomnia, which responds best to CBT-I.

Can CBD make insomnia worse?

It is uncommon, but some people report feeling more alert at larger amounts, and next-morning grogginess is a reported side effect. If either happens, taking less or taking it earlier in the evening is the usual first adjustment. Stop and speak to your GP if sleep gets noticeably worse.

How long does CBD take to work at night?

Oil held under the tongue is typically noticeable within 30 to 60 minutes, while capsules and edibles take 60 to 90 minutes because they pass through digestion. Judging whether it does anything at all takes longer, usually one to two weeks of consistent use at the same time each evening.

If your sleep difficulty is short-term and you want to try CBD as part of an evening routine, start low, keep the timing consistent and give it two weeks before you decide anything. You can compare formats and strengths across the CBD oil range, each with its batch report published. If this has been going on for months, book the GP appointment first.