CBD and melatonin: two mechanisms, no joint trial
Melatonin is a hormone that signals night to the body clock. CBD has no known hormonal action, and no effect on sleep has been demonstrated for it. No human trial has assessed the two together. In France, a gummy or oil combining them counts as a CBD food, which may not be sold.
Key takeaways
- A French food supplement must provide under 2 mg of melatonin a day; from 2 mg, melatonin is a prescription medicine.
- Compared with placebo, melatonin cut the time to fall asleep by 7 minutes on average in a 2013 meta-analysis.
- On insomnia severity, 150 mg of CBD did no better than a placebo in a 2024 trial.
- CBD slows CYP1A2, an enzyme that clears melatonin, and the pair has never been tested in humans.
Melatonin: a hormone that tells the time
The pineal gland, in the brain, releases melatonin at night. Unlike a sleeping pill, it does not knock you out. It tells the body that the rest period is beginning and keeps the biological clock in step with the day-night cycle. According to Anses, the French food safety agency, it also acts on body temperature, mood and the immune system.
Its measured effect on sleep is modest. A 2013 meta-analysis in PLoS One pooled 19 trials covering 1,683 people with primary sleep disorders. Against placebo, melatonin cut the time to fall asleep by 7 minutes on average and added 8 minutes of total sleep.
In France, status depends on the dose. Anses states that the rules allow food supplements providing less than 2 mg of melatonin a day. From 2 mg, melatonin becomes a medicine: Circadin, a prolonged-release tablet, is prescribed to patients aged 55 or over, for 13 weeks at most.
Under Regulation (EU) 432/2012, melatonin also carries two authorised health claims in the EU. One concerns reducing the time it takes to fall asleep, at 1 mg taken before bedtime. The other concerns the effects of jet lag, from 0.5 mg.
CBD and sleep: what the trials show
CBD (cannabidiol) is a hemp cannabinoid that produces no psychoactive high. It acts on several receptors, those of the endocannabinoid system among them, and no hormonal mechanism like melatonin's is known for it.
Controlled sleep trials are still few and small. In 2024 an Australian team gave 150 mg of CBD or a placebo every evening for two weeks to 30 adults with insomnia. The groups did not differ on insomnia severity, self-reported time to fall asleep or night-time waking. After two weeks, sleep efficiency measured at the wrist was better on CBD, and reported well-being was higher. Our feature on CBD and sleep goes through the other trials dose by dose.
Drowsiness, by contrast, is a well-documented side effect, especially at high doses. According to its product information, it affects 23% of patients on Epidyolex, the only CBD medicine. It counts as an adverse effect, and our article on CBD side effects places it among the others. CBD has no authorised health claim, so a seller cannot write that it helps you sleep.
What happens when you combine them
The effect of the combination on sleep has never been measured in a human trial. The one documented point concerns the liver, which clears both molecules.
According to the Circadin product information, melatonin is broken down mainly by the enzymes CYP1A1 and CYP1A2. Any drug that slows them raises melatonin levels: fluvoxamine, an antidepressant, increases exposure to melatonin 17-fold. CBD slows CYP1A2. In the Epidyolex product information, 1,500 mg of CBD a day almost doubled exposure to caffeine, which goes through the same enzyme (+95%). The document describes CBD as a weak inhibitor of that enzyme.
Two laboratory studies examined melatonin directly. A high dose of CBD multiplied melatonin exposure in mice by 2.85, according to a 2024 study. In 2025 a second team combined measurements in cells, rats and dogs with a computer model, which projects a worst-case 12-fold rise in exposure in humans. The figure is a projection and was never measured; all it says is that the interaction deserves testing.
The same authors present the combination as a possible approach to insomnia, with no human data to support it. Since 2018, Anses has advised favouring simple formulations that do not mix melatonin with other ingredients, and avoiding several supplements at once, to limit interactions. The enzyme mechanism is explained in our article on CBD interactions and the grapefruit effect.
What French law says about combined products
Gummies, oils or capsules that combine CBD and melatonin are foodstuffs. Swallowed CBD comes under Regulation (EU) 2015/2283 on novel foods, and no CBD ingredient has been authorised under it. On 20 May 2026 the French Ministry of Agriculture restated that foodstuffs containing CBD are not authorised for sale and extended checks to every channel, online sales included. Whatever its melatonin dose, a combined product sold in France today is therefore unlawful.
What remains on sale is detailed in our update on CBD regulation in 2026, and the article on the withdrawal of CBD gummies follows the format hit hardest. On 9 February 2026 EFSA published a provisional safe level of about 2 mg of CBD a day for a 70 kg adult, discussed in our article on EFSA's reference dose. The benchmark does not authorise any product.
Who should avoid one or the other
The two agencies have published similar lists. Anses advises against melatonin supplements for pregnant or breastfeeding women, children and teenagers, people with inflammatory or autoimmune diseases, and anyone whose activity demands sustained alertness. It asks for medical advice in case of epilepsy, asthma, mood disorders or medication, and recommends only occasional use.
For CBD, EFSA regards safety as not established under 25, during pregnancy and breastfeeding, and for people on medication. Both substances can make you drowsy, so do not drive after taking them. If your nights are disrupted over time, take the question to a doctor.
Frequently asked questions
No. CBD is a hemp cannabinoid; melatonin is a hormone made by the brain. Some products deliberately combine the two in one formula, and those are CBD foods that may not be sold in France.
The combination has not been assessed in any human trial. CBD slows the enzyme CYP1A2, which clears melatonin, and animal studies show higher melatonin exposure. Ask a doctor or pharmacist, especially if you are on a treatment.
A food supplement must stay below 2 mg of melatonin a day. Circadin, a 2 mg prolonged-release form, is a prescription medicine for people aged 55 or over.
The two have never been compared directly. Melatonin has a modest but measured effect on falling asleep and two authorised claims. In the 2024 trial, CBD did no better than a placebo on insomnia severity, and it has no authorised claim.
CBN is another cannabinoid, often marketed for the evening. It has no food authorisation either, and few trials have tested it on sleep. Our article on CBN and sleep reviews them.
Written by the Phytogrammes team
Each journal article draws on cited primary sources: ANSM, EFSA, EUR-Lex and peer-reviewed publications. Product profiles are distinguished from documented laboratory results. Our approach.
Article published on . CBD is not a medicine.