Medical Cannabis: What You Need to Know About THC, CBD, CBN, and CBC
by B. Kristine Burneko, MSN, APRN, PMHNP-BC, APHN-BC
Cannabinoids, including THC, CBD, CBN, CBC, and others, have moved from the margins of medical research into mainstream scientific and popular discussion. The word cannabinoid is a very generalized term encompassing a diverse group of compounds with different effects. Some occur naturally in the cannabis plant, while others are produced within the human body. Understanding the difference between these two systems is critical in order to understand both the therapeutic potential and current limitations in the medical use of cannabis.
Internal Cannabinoids and Plant Cannabinoids
Endocannabinoids are found naturally in the human nervous system and are signaling molecules that help to regulate homeostatic processes such as pain perception, immune activity, appetite, mood, memory, sleep, and stress responses. Currently, the two best-researched endocannabinoids are anandamide (AEA) and 2-arachidonoylglycerol (2-AG) (Murray et al., 2024).
Two of the principal endocannabinoid receptors (parts of a neuron that receive these endocannabinoids) are called CB1 and CB2. CB1 receptors are abundant in the brain and nervous system, whereas CB2 receptors are mostly found in immune cells and peripheral tissues (Murray et al., 2024). Endocannabinoids are produced on demand rather than stored in large quantities, allowing the body to fine-tune its response when homeostasis is disturbed (Murray et al., 2024).
Plant-derived cannabinoids are known as phytocannabinoids and occur in several plants in addition to cannabis (though not necessarily in the form of THC, CBD, CBN, or CBC): black pepper, lavender, cinnamon, basil, cacao, rhododendron, echinacea, and many others (Russo, 2016). These cannabinoids can interact with our built-in endocannabinoid system, but not all do so in the same way. This is one reason that the CBD, THC, CBN, and CBC found in the cannabis plant can produce substantially different biological effects.
THC: The Intoxicating Cannabinoid
Delta-9-tetrahydrocannabinol (THC) is the cannabinoid primarily responsible for the intoxicating effects associated with cannabis. THC activates CB1 and CB2 receptors, with its effects on CB1 causing changes in perception, memory, coordination, mood, and appetite (Murray et al., 2024).
THC and THC-like compounds have demonstrated medical benefits in several areas: to reduce chemotherapy-induced nausea and vomiting, to stimulate appetite, and modulate chronic pain in certain very specific clinical circumstances. In the instance of chronic pain relief, however, the research suggests that the benefit appears to be modest and accompanied by many adverse effects including dizziness, sedation, cognitive impairment, nausea, and vomiting (Whiting et al., 2015).
CBD: The Non-Intoxicating but Pharmacologically Active Cannabinoid
Cannabidiol (CBD) does not produce the characteristic intoxication of THC. Its pharmacology is considerably more complex than simply "blocking" the action of THC as is commonly believed. CBD interacts with multiple molecular targets and can influence cannabinoid processing, nervous system conduction, chemical metabolism, inflammatory pathways, and several other signaling systems (Murray et al., 2024).
The strongest clinical evidence for CBD involves certain severe forms of epilepsy: Dravet syndrome, Lennox-Gastaut syndrome, and seizures related to tuberous sclerosis. Specific doses of purified, isolated, pharmaceutical-grade CBD have been shown in randomized clinical trials to reduce seizure in these conditions and have therefore been federally approved for manufacture and prescription (under the trade name "Epidiolex") for these specific conditions in patients 1 year and older (Devinsky et al., 2017, 2018; Thiele et al., 2021).
CBD is also being investigated for anxiety, pain, inflammation, sleep, and other conditions. However, promising laboratory findings should not be confused with established clinical efficacy. Human-trial evidence remains inconsistent for many of these applications, and the preliminary conclusions pertain only to pharmaceutical-grade CBD and not commercially available oils, gummies, or other products which can differ substantially in their concentration and quality. Importantly, CBD can also sabotage the efficacy of other medications (including blood thinners, antidepressants, thyroid medications, and antiepileptic medications) by interfering with their metabolism in the body, either super-concentrating them or dampening their therapeutic effects (Balachandran et al., 2021).
CBN: The Unproven Sleep Aid
Cannabinol (CBN) is a naturally occurring cannabinoid formed in part by the breakdown THC. It appears to have considerably less intoxicating activity than THC, although describing CBN simply as "non-intoxicating" may overstate what is known about its effects. The compound has attracted considerable attention as a potential sleep aid though much of the evidence remains preclinical or based on studies that are inappropriate to generalize. Claims that CBN is a proven natural sleep medication are not evidence-based.
One study in 2023 did find that a specific dose of isolated CBN reduced some subjective measures of sleep disturbance for people not formally diagnosed with insomnia - although there was no statistically significant improvement in the primary sleep-quality measure (awakening after sleep onset) (Spielman et al., 2023). A subsequent small study in adults diagnosed with insomnia also reported several subjective and objective sleep-related effects from CBN, although once again, no improvement in the primary variable (awakening after sleep onset) was evident and the authors emphasized the need for larger and longer clinical trials before sound conclusions can be reached (Lavender et al., 2026). CBN remains a promising but still investigational sleep compound and is not an evidence-based sleep medication.
CBC: Intriguing, but Understudied
Cannabichromene (CBC) is another naturally occurring phytocannabinoid. Unlike THC, it is not associated with THC-like intoxication. Laboratory research suggests that CBC interacts with certain neuronal pathways and other chemical targets and may influence pain and inflammatory pathways (Sepulveda et al., 2024), although research is still at an early stage and is not appropriate to be used as evidence in the therapeutic setting.
Evidence has emerged that CBC likely includes analgesic, anti-inflammatory, antimicrobial, and other potential effects, but most of this work has been conducted in laboratory or animal models. A recent comprehensive review concluded that CBC remains critically understudied and that rigorous clinical trials are needed to determine whether the laboratory findings translate into meaningful benefits for patients (Sepulveda et al., 2024).
A Case for Discernment and Cautious Optimism
Cannabinoids should not be regarded as interchangeable. THC has established psychoactive effects and demonstrated therapeutic applications; purified CBD has strong evidence for specific seizure disorders; CBN is an emerging therapy in sleep research; and CBC remains largely investigational for antimicrobial and anti-inflammatory effects.
The take-home lesson is that cannabinoid medicine is not simply about cannabis. It is about understanding a sophisticated biological signaling system and determining how individual molecules can modify that system safely and predictably. As research advances, the most important questions are not simply whether cannabinoids "work," but which cannabinoid, at what dose, by what route, for which condition, in which patients, and with what risks.
This scientific framework leads to an important principle of cannabinoid (and all other types of) medicine: therapeutic effects of a compound are always countered by adverse effects. Responsible therapeutic use of any cannabinoid must be carefully considered, in a specific, personal, and precise context, by a licensed and registered medical provider trained in pharmacology and preferably certified in phytomedicine or the cannabis medicine specialty.
References
Balachandran, P., Elsohly, M., & Hill, K.P (2021). Cannabidiol Interactions with Medications, Illicit Substances, and Alcohol: a Comprehensive review. Journal of General Internal Medicine, 36(7), 2074-2084. https://doi.org/10.1007/s11606-020-06504-8
Devinsky, O., Cross, J. H., Laux, L., Marsh, E., Miller, I., Nabbout, R., Scheffer, I. E., Thiele, E. A., & Wright, S. (2017). Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome. The New England Journal of Medicine, 376(21), 2011–2020. https://doi.org/10.1056/NEJMoa1611618
Devinsky, O., Patel, A. D., Cross, J. H., Villanueva, V., Wirrell, E. C., Privitera, M., Greenwood, S. M., Roberts, C., Checketts, D., VanLandingham, K. E., & Zuberi, S. M. (2018). Effect of cannabidiol on drop seizures in the Lennox–Gastaut syndrome. New England Journal of Medicine, 378(20), 1888–1897. https://doi.org/10.1056/NEJMoa1714631
Lavender, I., et al. (2026). Cannabinol for acute treatment of insomnia disorder in a randomized placebo-controlled crossover trial. Journal of Sleep Research, 35(4), e70284. https://doi.org/10.1111/jsr.70284
Murray, C. H., Gannon, B. M., Winsauer, P. J., Cooper, Z. D., & Delatte, M. S. (2024). The development of cannabinoids as therapeutic agents in the United States. Pharmacological Reviews, 76(5), 915–955. https://doi.org/10.1124/pharmrev.123.001121
Russo, E. B. (2016). Beyond cannabis: Plants and the endocannabinoid system. Trends in Pharmacological Sciences, 37(7), 594–605. https://doi.org/10.1016/j.tips.2016.04.005
Sepulveda, D. E., Vrana, K. E., Kellogg, J. J., Bisanz, J. E., Desai, D., Graziane, N. M., & Raup-Konsavage, W. M. (2024). The potential of cannabichromene (CBC) as a therapeutic agent. Journal of Pharmacology and Experimental Therapeutics, 391(2), 206–213. https://doi.org/10.1124/jpet.124.002166
Spielman, A. J., et al. (2023). A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality. Psychopharmacology Bulletin, 53(4), 7–19. https://doi.org/10.1037/pha0000682
Thiele, E. A., Marsh, E. D., French, J. A., Mazurkiewicz-Beldzinska, M., Benbadis, S. R., Joshi, C., Lyons, P. D., Taylor, A., Roberts, C., Sommerville, K., & GWPCARE4 Study Group. (2018). Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome. The Lancet, 391(10125), 1085–1096. https://doi.org/10.1016/S0140-6736(18)30136-3
U.S. Food and Drug Administration. (2026). Epidiolex (cannabidiol) oral solution: Prescribing information. U.S. Department of Health and Human Services. FDA Epidiolex prescribing information
Whiting, P. F., Wolff, R. F., Deshpande, S., Di Nisio, M., Duffy, S., Hernandez, A. V., Keurentjes, J. C., Lang, S., Misso, K., Ryder, S., Schmidlkofer, S., Westwood, M., & Kleijnen, J. (2015). Cannabinoids for medical use: A systematic review and meta-analysis. JAMA, 313(24), 2456–2473. https://doi.org/10.1001/jama.2015.6358
