Mice given cannabinol, the cannabis compound sold in gummies and tinctures as a sleep aid, became less responsive to it after just three days of twice-daily doses, and showed withdrawal-like signs when it was removed, according to UConn Today. The study, published in Drug and Alcohol Dependence, also found that mice trained to recognize THC treated CBN as if it felt like THC.

The findings challenge how CBN is often marketed: as a safe, herbal, plant-derived sleep supplement that is less psychoactive than THC. Researchers at the University of Connecticut caution that these are mouse results, and the effects in people remain unknown.

The timing matters for shoppers — federal changes to the legal definition of hemp take effect in the coming weeks, and the question of whether CBN acts like THC is directly relevant to how those rules apply.

Signs of Tolerance and Withdrawal

Lead author Olivia Vanegas, a recent UConn Ph.D. graduate, and Steven Kinsey, a professor in UConn's Elisabeth DeLuca School of Nursing, gave mice CBN twice daily for three days.

By the end, the mice responded less to the compound, a hallmark of tolerance. When CBN was withdrawn, the mice showed head twitching and paw fluttering, signs researchers use to identify dependence in rodents.

In a drug discrimination test, mice trained to recognize the high from THC responded to CBN the same way. That suggests CBN activates biological pathways similar to THC's.

"Our findings suggest consumers should be aware repeated use may carry risks," Kinsey said in the university's announcement. He also said CBN may still have therapeutic value, but dosing and long-term effects remain unclear. Vanegas described the marketing of minor cannabinoids such as CBN as largely running ahead of the science, and Kinsey's advice to consumers was simple: buyer beware.

Mixed Effects on Inflammation and Immunity

The immune results cut both ways — at lower doses that did not produce THC-like effects, CBN reduced inflammation in the mice. But during a simulated bacterial infection, CBN weakened the body's defenses.

That combination raises questions for people who use CBN nightly, particularly during cold and flu season or while managing other health conditions. It does not show that CBN harms immunity in humans, only that the mouse data point to a question worth studying.

Marketing Has Outrun the Evidence

CBN has grown popular as a sleep product, but UConn notes that little is known about the quality of sleep it produces. This study did not measure sleep outcomes at all. It focused on dependence, perception, and immune effects.

The researchers point out that history offers a warning. Some earlier sleep aids were widely used before they were found to be dangerously habit-forming.

The evidence has clear limits. This was a short animal study, and the university's report does not give the doses used, so it is unclear how they compare with a typical gummy. Mice and humans metabolize drugs differently. There are no large, long-term human trials showing whether people develop tolerance or withdrawal from CBN at retail doses.

Who could face the most risk? People who use CBN every night for long periods, people combining it with alcohol or other sedatives, and anyone with a history of substance use problems. Products also vary widely in labeled and actual content, since supplements are not reviewed by the FDA for safety or effectiveness before sale.

Federal Hemp Rules Approach

The study arrives as federal rules on hemp products change. A 2025 law narrowed the federal definition of hemp, according to law firm Vicente LLP. A ban on synthetic cannabinoids takes effect Nov. 12, 2026, while a new total-THC standard and a limit of 0.4 milligrams of total THC per container take effect Dec. 11, 2026, after a delay signed in September.

The total-THC standard counts THC and "other cannabinoids with similar effects." The law does not name CBN, and it is not yet clear how regulators will treat it. Findings that CBN feels like THC to mice could become part of that debate, but a single animal study does not settle it.

Practical Steps for Shoppers

If you use CBN for sleep, talk with a doctor or pharmacist, especially if you take other medications or drink alcohol. Look for products with third-party lab testing that lists actual cannabinoid content. Avoid combining CBN with other sedatives, and do not drive if you feel drowsy or impaired.

Store gummies out of reach of children and pets, since they can look like candy. If a child eats a cannabis product, call Poison Help at 1-800-222-1222, or 911 for trouble breathing or unresponsiveness.

Watch for warning signs of dependence, such as needing more to get the same effect, trouble sleeping when you skip a dose, or feeling restless without it. People with persistent insomnia should seek medical evaluation, since behavioral therapy is a well-established first-line treatment.

Next, the researchers say studies in humans, especially at high doses and over long periods, are needed. Controlled trials comparing CBN with placebo would also help answer the most basic question for buyers: whether it actually improves sleep, and at what cost. Nature World News will follow how federal agencies apply the new hemp rules to products like CBN.

The bottom line: in mice, CBN produced tolerance within days, THC-like effects, and withdrawal signs. Human evidence is missing, but the gap between "natural sleep aid" marketing and the science is wide enough that nightly users should proceed with caution.

What Readers Want to Know

What is CBN? Cannabinol, a cannabis compound sold in gummies, tinctures and capsules, often marketed as a sleep aid.

What did the study find? Mice developed tolerance within three days, showed withdrawal signs and perceived CBN as similar to THC.

Does this apply to people? Not necessarily. The study was in mice, and human effects are unknown.

Did the study show CBN improves sleep? No. It did not measure sleep, and evidence on sleep quality remains limited.

Are federal rules changing? Yes. New hemp rules take effect Nov. 12 and Dec. 11, 2026, but it is unclear how CBN will be treated.

What should CBN users do? Talk with a doctor, avoid mixing it with alcohol or sedatives and watch for signs of dependence.