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CBN

, said see bee en abbr.

CBN (cannabinol): the cannabinoid that forms as THC ages

  1. Cannabinol, the cannabinoid that forms when THC breaks down with age, heat, light and air.

By The glossary desk. Published

CBN /ˌsiːˌbiːˈɛn/ abbr. Cannabinol. The cannabinoid that forms when THC breaks down with age, heat, light and air.

  1. (chemistry) The compound C21H26O2, molar mass 310.4 g/mol (PubChem CID 2543). It has four fewer hydrogen atoms than THC, which is what oxidation takes away.
  2. (lab reports) A line on a certificate of analysis. In flower it reads as a freshness marker: the older or worse-stored the bud, the more of its THC has become CBN.
  3. (commerce) Short for products sold for their CBN content.

Origin Cannabi(s) + -n- + -ol. It was the first cannabinoid to be isolated: Thomas Wood, W. T. Newton Spivey and Thomas Easterfield described it in 1899, from Indian hashish (Wood, Spivey and Easterfield, 1899). CBD and THC followed decades later.

See also cannabidiol · CBG · CBDA · CBDV

Checked against the sources below on Oct. 4, 2026.

Notes

Where does CBN come from?

Mostly from THC, after harvest. The plant makes very little CBN itself. As THC is heated or meets air and light over time, it loses hydrogen and becomes CBN. A study of cannabis resin held at 50 °C to 80 °C measured THC falling and CBN rising, faster at the higher temperatures (Jaidee and others, 2022). The same thing happens slowly on a shelf.

What does a high CBN number tell a buyer?

That the THC in the sample has been breaking down. Fresh flower usually shows little CBN. A clearly higher figure, from the same lab, means old stock, warm storage or too much air. Compare the test date on the report with the date you buy.

Does CBN act like THC?

Weakly. A 2022 review describes CBN acting at the same cannabinoid receptors as THC, but more weakly, and sets out its history, how chemists make it and what has been studied (Maioli and others, 2022). Studies in people are few. The FDA has approved no CBN product, and claims made for CBN products have not been through FDA review.

Is CBN covered by hemp law?

Federal hemp law measures THC. From Dec. 11, 2026, the definition counts total THC, THCA included, at 0.3% of dry weight. It also excludes final products that contain cannabinoids “synthesized or manufactured outside the plant”, which, as written, reaches CBN made by converting another cannabinoid in a lab (P.L. 119-37, sec. 781; date set by H.R. 6500, sec. 2019). State law varies; check yours.

The shop on this site

The shop does not sell CBN products. Each flower’s lab report on file shows its own cannabinoid lines. Our menu today is high-THCA hemp flower, not CBD flower. Smoked, it gets you high and shows up on THC drug tests.

Sources

Questions

What is CBN?
Cannabinol, C21H26O2. Fresh cannabis holds very little; most CBN forms when THC breaks down as the plant material ages or is heated and exposed to air and light.
What does CBN mean on a lab report?
That the sample holds cannabinol. In flower, a high CBN figure next to falling THC usually means the material is old or was stored warm and exposed to air.
Is CBN the same as CBD?
No. CBN comes from THC, not from CBD, and it has a different structure. The letters are close only because both names begin with cannabi-.
Is CBN approved as a medicine?
No. The FDA has approved no CBN product for any use. This glossary makes no claim for it.

See also CBG (cannabigerol): what it is, and why it is called the parent cannabinoid · CBDV (cannabidivarin): CBD's shorter-chained relative · CBDA (cannabidiolic acid): the raw form of CBD

A note on our shop: it sells high-THCA hemp flower, not CBD flower.