CBN (Cannabinol)

CBN (Cannabinol): What It Is, How It Forms, and What the Sleep Research Actually Shows

CBN (cannabinol) is a mild cannabinoid that forms when THC breaks down with age, heat and air. It binds the brain's CB1 receptor with about one-tenth the affinity of THC, so on its own it does not produce a real high. In the largest human trial (293 people), 20 mg of CBN a night for a week reduced nighttime awakenings but did not help people fall asleep faster.

That's the short version of a compound with a big reputation — "the sleepy cannabinoid in old weed." Below: how CBN forms and why aged flower has more of it, whether it gets you high, every human sleep trial in one table, what "CBN" on a gummy label really means, how much people take, side effects, drug tests and legality. Every number links to its source. If you came here for the flower, start with our THCA flower collection, where every batch ships with a third-party lab report.

CBN at a Glance: The Numbers

Sources: Corroon 2021, Bonn-Miller 2024, Lavender 2026, Karniol 1975, Kroner 2020, Maioli 2022, Satybaldiyeva 2025. Checked November 9, 2026.

What Is CBN?

CBN is a phytocannabinoid — one of the 150-plus compounds in the cannabis family — and it is unusual because the plant barely makes it. According to a 2022 review in Plants, no plant pathway for CBN or its acid form has been identified. Instead, CBN is "a degradation artifact" of THC: when THC is exposed to air, part of the molecule oxidizes and CBN is the result. Small amounts of CBNA, the acid form, have also turned up in some hemp, which suggests THCA can oxidize too, before it is ever heated.

CBN was also the first cannabinoid ever isolated. Chemists Wood, Spivey and Easterfield at Cambridge pulled it out of hashish in the 1890s, but the structure was not solved until 1940. Their hash had sat for months on the trip from India, and careless storage had turned much of its THC into CBN — which muddied early research on what made cannabis active.

Today CBN is mostly a sleep product. In a 2025 survey of 1,523 US adults, 4.5% had ever used CBN, and the most common medical reason was insomnia (15.4%), followed by pain (11.1%) and anxiety (10.9%).

How Does CBN Form? Why Old Weed Has More of It

CBN forms when THC oxidizes. Time, warmth and air drive it, so the older and worse-stored the cannabis, the more of its THC has turned into CBN. A 2026 long-term storage study that tracked plant material, extracts and isolates at room temperature, in the fridge and in the freezer found that room temperature "accelerated the degradation of THC into cannabinol (CBN)," while freezer storage at −20°C preserved cannabinoids best. CBD-only products, by contrast, stayed stable even at room temperature.

Here's the chain in THCA flower, the format we sell:

1. THCA sits in fresh flower. It doesn't get you high (see does THCA get you high?).
2. Heat — a lighter, vape coil or oven — strips off a carboxyl group and turns THCA into delta-9 THC. By weight, 100 mg of THCA yields about 87.7 mg of THC (the 0.877 factor labs use; see THCA vs THC).
3. Air, time and warmth slowly oxidize THC into CBN. Some THCA may oxidize toward CBN's acid form even before heating.

How to keep your flower from turning into CBN

If CBN is what you're after, there are better ways to get it than letting a jar go stale — old flower also loses its terpenes. If you want your THC to stay THC:

• Airtight glass, not baggies. Less air means less oxidation.
• Cool and dark. Room temperature speeds THC-to-CBN conversion in the storage study above; heat and sunlight in a car or on a windowsill are worse.
• 58–62% humidity packs keep flower from drying out and crumbling.
• Buy what you'll use. Fresh flower in a reasonable size beats a big stash that sits for a year.
• Read the COA. If a lab report lists CBN, a high CBN number next to a low THCA number is a sign of older or poorly stored material. Our guide on what a good THCA percentage is explains the potency lines.

Does CBN Get You High?

Not in a meaningful way on its own. CBN binds the CB1 receptor — the one behind the cannabis high — with about one-tenth the affinity of THC, and in a 1975 human study 50 mg of oral CBN alone produced no "drugged" or "drowsy" feeling.

That 1975 study gave five men placebo, 50 mg CBN, 25 mg THC, or mixes of the two, a week apart. THC raised heart rate and made volunteers feel "drugged, drunk, dizzy, and drowsy." CBN alone did none of that. But CBN plus THC made them feel more drugged, drunk, dizzy and drowsy than THC alone. A companion animal study found the same pattern: CBN was weaker than THC but added to THC's depressant effects, including sleeping time in mice.

There's one twist. A 2025 rat study in Neuropsychopharmacology found that the body converts CBN into a metabolite, 11-hydroxy-CBN, that reached brain levels as high as CBN itself and acted on CB1 "with comparable potency and efficacy to Δ9-THC." That was in rats, but it's a reason large oral doses may not feel as inert as the receptor numbers suggest.

What does CBN feel like? At typical product doses, most people describe a mild, relaxed heaviness rather than a high. When CBN shows up alongside THC — in aged flower or a CBN + THC gummy — expect THC's effects, possibly a little sleepier. For the THC side of that equation, see our delta-9 THC entry.

What Does CBN Do to Your Body?

CBN acts weakly on both cannabinoid receptors, CB1 and CB2. In people, the only outcome tested in modern controlled trials is sleep; claims about pain, inflammation, appetite and bacteria come from lab-dish and animal studies.

Here's where each claim actually stands, from strongest evidence to weakest:

• Sleep (human trials): modest, mixed results — see the next section.
• Sleep architecture (rats): more total sleep and more NREM and REM sleep, per the Arnold 2025 study. The NREM effect was compared to the sleep drug zolpidem.
• Appetite (rats): CBN increased food intake and feeding time in rat studies summarized by Maioli et al..
• Antibacterial (lab dish): CBN, along with CBD, CBG, CBC and THC, showed potent activity against several MRSA strains in a 2008 Journal of Natural Products study. No human data.
• Pain and inflammation: mostly animal and cell work. No CBN-only human pain trial has been published that we could find.

Our honest read: CBN is real and biologically active, but outside sleep, every benefit you see on a label is extrapolated from animals or petri dishes. Nothing here means CBN treats or cures anything.

Does CBN Actually Make You Sleepy?

Possibly a little, at doses higher than most products contain. The best trial so far (293 people, 20 mg nightly) found fewer nighttime awakenings but no faster sleep onset; a smaller insomnia trial found 300 mg helped people fall asleep faster but did not reduce time awake during the night.

As recently as 2021, a review by Jamie Corroon screened 99 human studies and found no clinical trial of CBN using validated sleep questionnaires or polysomnography. It concluded there was "insufficient published evidence to support sleep-related claims" and noted that products marketed for sleep typically contained 5 mg or less. Since then, two trials have been published:

Sources linked in each row. "Polysomnography" is an overnight sleep-lab recording of brain waves, breathing and movement.

What this means in plain terms: CBN is not a proven sleep aid, but it's no longer pure lore either. The effects that did show up were modest, came at 20–300 mg, and lasted for the week tested. The 2026 authors called for "larger, longer trials." If the "sleepy old weed" feeling is real, the THC + CBN interaction probably explains part of it — aged flower still has plenty of THC, and CBN may deepen its drowsy side. Our planned guide on CBN for sleep goes deeper, and THC for sleep covers the other half.

CBN vs CBD vs THC vs CBG: How They Compare

CBN is the aged form of THC: milder than THC, more active than CBD at the CB1 receptor, and sold almost entirely for sleep. Here's how it lines up against the cannabinoids people most often confuse it with:

Related reading: CBG, the "mother cannabinoid" · CBDA, the raw form of CBD · CBGA · THCV · CBN vs CBD, side by side.

What Is CBN in Gummies and Edibles?

"CBN" on a gummy label means cannabinol has been added, usually as a sleep product and usually alongside THC, CBD or both. The dose matters: the 2021 Corroon review found many sleep products contained 5 mg or less, while the trials that found effects used 20–300 mg.

Before you buy a CBN gummy or edible, check four things:

1. Milligrams of CBN per piece. A "CBN gummy" with 2 mg of CBN is mostly a vehicle for whatever else is in it.
2. What else is in it. Many CBN products are really THC products with a little CBN. If there's THC, the THC is doing most of the work — dose it like a THC edible (our indica edibles and indica gummies guides cover that).
3. A batch-matched COA. The lab report should list CBN and delta-9 THC in milligrams per serving, from an accredited lab.
4. Timing. Edibles are absorbed through the gut, so they come on slower and last longer than smoked flower. Don't take a second dose because the first "isn't working" yet.

Comparing formats? Our upcoming guides on tinctures vs edibles and the best THC gummies for sleep walk through onset and dosing side by side.

What Is CBN in Weed?

In flower, CBN is mostly a freshness indicator: fresh, well-stored cannabis has little of it, and aged or heat-exposed cannabis has more, because THC turns into CBN over time. That's why "old weed makes you sleepy" is a common saying — the stash has less THC, more CBN, and a flatter terpene profile.

There's no such thing as a "CBN strain" in the breeding sense, since the plant doesn't build CBN directly. If you're picking flower for the evening, look at the strain's type and terpenes instead. Sedating terpenes like myrcene and linalool show up in many evening strains, and our guide to indica vs sativa explains why the labels only get you so far. Purple Punch and Permanent Marker are two evening favorites in the encyclopedia.

How to Use CBN — and How Much

There is no established CBN dose. Human sleep trials used 20 mg nightly for a week and single doses of 30 mg and 300 mg; most retail products contain far less. If you try it:

• Pick a format with a clear dose. Soft gels, gummies and tinctures with a milligram number per serving are easier to measure than aged flower, where the CBN content is unknown unless there's a COA.
• Start with the lowest labeled serving and take it once. Wait a full night before changing the amount.
• Watch the THC. If the product contains THC, the THC sets your dose, not the CBN. New to THC? Start very low — our how much THC for sleep guide and the microdosing guide cover starting doses.
• Don't stack it with alcohol or sleep medication without talking to a doctor.
• Leave room for the morning. THC-containing products can leave you groggy or impaired the next day. Don't drive until you know how a product affects you.

CBN Side Effects: Who Should Not Take CBN?

In trials, CBN was generally tolerated: 20 mg nightly for seven nights caused no more daytime fatigue than placebo. But there's no long-term safety data, and CBN can add to THC's drowsiness and dizziness.

In the 2026 insomnia trial, researchers logged 247 mild-to-moderate adverse events across all three arms, including placebo, over the single nights tested. The 2024 trial found no difference from placebo in daytime fatigue. The 1975 study is the main warning sign: combined with THC, CBN made people feel more dizzy and drowsy.

Skip CBN, or talk to a doctor first, if you:

• Are pregnant or breastfeeding.
• Take sedatives, sleep medication, or other prescriptions.
• Will drive, operate machinery, or need to be sharp soon after.
• Are subject to drug testing (see below).
• Are under 21. All cannabinoid products on our site are for adults 21+.

Is CBN safe to take every night? Nobody has tested it for longer than about a week. Seven nights at 20 mg looked fine in the 2024 trial; beyond that, it's unknown.

Is CBN Good for Anxiety?

There is no clinical trial showing CBN helps anxiety. Some people use it that way — 10.9% of CBN users in the 2025 national survey named anxiety as a reason — but that tells you why people take it, not whether it works. If anxiety is your main concern, CBD has far more human research than CBN; see our upcoming CBN vs CBD comparison.

Will CBN Show Up on a Drug Test?

It can. In a 2020 lab study, CBN cross-reacted with two common urine screens for THC: one needed about 5 times more CBN than THC metabolite to read positive, the other about 20 times more, and CBN added to any THC already in the sample.

That study in The Journal of Applied Laboratory Medicine tested CBD, CBN, CBC and CBG. Only CBN tripped the THC screens. A lab confirmation test (GC-MS or LC-MS/MS) can tell CBN apart from THC, but many CBN products also contain THC, which will show up. If you're tested for work, sport or probation, avoid CBN products. Our guide on whether THCA shows up on a drug test covers detection windows.

Is CBN Legal?

As of November 2026, hemp-derived CBN products containing no more than 0.3% delta-9 THC by dry weight are sold under the 2018 Farm Bill. Many states set their own rules for hemp-derived cannabinoids, and some restrict them. Check your state before ordering — our hemp THC legal status page tracks where things stand. All products are for adults 21+. We do not ship to Colorado. This is not legal advice.

Shop Premium Flower at Diesel Hemp

• Permanent Marker THCA Flower — our indica-leaning evening pick, $89 $65 for a ½oz.
• THCA Flower — the full lineup, grown in Colorado by Diesel Hemp and partner farms.
• THCA Live Rosin — solventless, pressed fresh.
• CBD Soft Gels and CBD Gummies — non-intoxicating, full-spectrum.
• Delta 9 THC Gummies — hemp-derived THC edibles.

More CBN and sleep guides: CBN vs THC · CBN Gummies · CBN Dosage · Does CBN Show Up on a Drug Test? · CBN vs Melatonin · CBN for Anxiety

Frequently Asked Questions

What is CBN?

CBN (cannabinol) is a cannabinoid that forms when THC oxidizes as cannabis ages. The plant does not make much of it directly. It was the first cannabinoid ever isolated, in the late 1800s, and it binds the CB1 receptor with about one-tenth the affinity of THC, so it is far milder.

Does CBN get you high?

Not in any meaningful way on its own. In a 1975 study, 50 mg of oral CBN alone did not make volunteers feel drugged, drunk or drowsy, while THC did. CBN has about one-tenth of THC's affinity for the CB1 receptor. Combined with THC, it made volunteers feel slightly more drugged, dizzy and drowsy than THC alone.

What does CBN do to your body?

CBN acts weakly on the CB1 and CB2 cannabinoid receptors. In human trials it has shown modest sleep effects: 20 mg a night for seven nights reduced nighttime awakenings in a 293-person trial, and a single 300 mg dose shortened time to fall asleep in a 20-person trial. Other reported effects, such as antibacterial activity and appetite stimulation, come from lab and rat studies only.

Does CBN actually make you sleepy?

Possibly, but the evidence is thin. In a 2024 trial of 293 poor sleepers, 20 mg of CBN reduced nighttime awakenings and overall sleep disturbance but did not help people fall asleep faster. In a 2026 trial of 20 adults with insomnia, 300 mg shortened sleep onset and improved sleep quality, but neither 30 mg nor 300 mg changed time awake after falling asleep, the main outcome.

How is CBN different from CBD?

CBN forms when THC breaks down with age, while CBD is made by the plant from CBGA. CBN binds the CB1 receptor weakly and is mildly active; CBD barely binds it and does not intoxicate. CBN is mostly sold for sleep, CBD for general wellness. CBN cross-reacts with some THC drug-test screens; pure CBD generally does not.

What is CBN in gummies?

CBN in gummies is cannabinol added to an edible, usually as a sleep product and often mixed with THC or CBD. A 2021 review found that many CBN products marketed for sleep contain 5 mg or less per serving, while the clinical trials that found an effect used 20 mg to 300 mg. Check the label for milligrams per gummy and the COA for what else is in it.

How much CBN should I take?

There is no established dose. Human sleep trials have used 20 mg nightly (seven nights) and single doses of 30 mg and 300 mg. If you try a CBN product, start with the lowest labeled serving, take it once, and wait a full night before changing the amount. Talk to a doctor first if you take other medications.

Is CBN safe to take every night?

No study has tested nightly CBN for longer than about a week. In a 2024 trial, 20 mg every night for seven nights did not cause daytime fatigue compared with placebo. Long-term safety is unknown, and products that combine CBN with THC carry THC's risks, including impairment the next morning.

Who should not take CBN?

Skip CBN if you are pregnant or breastfeeding, under 21, subject to drug testing, or about to drive or operate machinery. Talk to a doctor first if you take sedatives, sleep medication or other prescriptions, because a 1975 study found CBN added to THC's drowsy and dizzy effects.

Is CBN good for anxiety?

There is no clinical trial showing that CBN helps anxiety. In a 2025 survey of 1,523 US adults, 10.9% of CBN users said they used it for anxiety, behind insomnia (15.4%) and pain (11.1%), but that measures why people use it, not whether it works.

Will CBN show up on a drug test?

It can. A 2020 lab study found CBN cross-reacts with two common urine screens for THC: one needed about 5 times more CBN than THC metabolite to trigger a positive, the other about 20 times more, and CBN added to any THC already present. Many CBN products also contain THC. If you are tested, avoid CBN products.

Related Entries

• How Much CBD Should I Take?
• How Long Does CBD Take to Work?
• THCA vs THC — the step before CBN: how heat turns THCA into THC.
• Delta-9 THC — the cannabinoid CBN forms from.
• CBG — another non-intoxicating minor cannabinoid, with the same thin-evidence problem.
• CBDA — the raw acid form of CBD.
• CBGA — the precursor every major cannabinoid is built from.
• Myrcene — the terpene most often linked to "couch-lock."
• Indica Edibles — how evening edibles are dosed.
• CBN vs CBD and Indica or Sativa for Sleep? — the sleep series.
• Browse the Full Diesel Hemp Encyclopedia