If you have a jar of sleepy gummies on your nightstand, this one's for you.
What CBN is
CBN, short for cannabinol, comes from the cannabis plant. It's in gummies, drops and capsules, usually with a moon on the label and the promise of a calm, THC-free night. "CBN is everywhere right now," said Steven Kinsey, a professor at UConn's school of nursing. "It's marketed as a safe, herbal sleep supplement."
What the mice showed
His team gave mice CBN twice a day for several days. Three things stood out. First, tolerance: the same dose did less and less. Second, withdrawal: when the effect was cut off, the mice twitched their heads and fluttered their paws, the mouse version of the shakes. Third, mice trained to recognise THC, the part of cannabis that gets you high, reacted to CBN as if it were THC.
There was one more twist. At low doses, CBN calmed inflammation. But during a fake bacterial infection, it weakened the body's defences.
"The marketing of minor cannabinoids is pretty wild right now," said lead author Olivia Vanegas.
Before you panic
These were mice, not people, and the study didn't test sleep at all. Nobody knows yet how a mouse dose compares to one gummy. Kinsey still thinks CBN "may still have therapeutic value." His advice for now: "buyer beware."
The rules are moving too. New US limits on THC-like hemp products start in December 2026, and it isn't clear yet whether CBN will be caught by them.
So if you use them every night, it's worth a chat with your doctor. Sheep counting, at least, has no withdrawal.