Topical cannabidiol oil was studied in 29 people with lower limb peripheral neuropathy. After using the oil for 4 weeks, the people had less intense and sharp pain and fewer other uncomfortable sensations.
Early research suggests that 160 mg of cannabidiol before bed significantly improves sleep duration compared to a placebo in patients with insomnia. Smaller doses did not have this effect. Also, patients did not feel drowsy the next morning morning.
Another review with meta-analysis of 104 studies evaluated cannabinoids for the treatment of chronic non-cancer pain. Within this review and analysis, the effect of cannabinoids on sleep was also examined. There was low-quality evidence of improved sleep.
CBD should be used according to the manufacturer’s instructions. A person should read and follow the label carefully. Use no more than instructed. Using more may increase the chance of side effects or it may cause other problems.
Reviews and meta-analyses of cannabinoids found the following:
CAUTION: Taking CBD with other herbs that cause drowsiness or sleepiness may increase this effect.
Medical cannabis users reported they used cannabis with higher CBD and lower THC concentrations for their insomnia. They also reported a decrease in the time required to fall asleep.
According to a 2012 study in the Journal of Experimental Medicine, rats injected with inflammatory chemicals in their hind feet experienced less inflammation and neuropathic pain when treated with an oral dose and spinal injection of CBD.
CBD’s exact mechanism of action is unclear. Unlike THC, CBD has a relatively low affinity for cannabinoid receptors in the brain. These are the molecules to which THC binds to elicit its psychoactive effects.
Potential drug-drug interactions with CBD include:
CBD oil is an extract of Cannabis indica or Cannabis sativa—the same plants that, when dried, make marijuana. CBD oil is believed by some to treat pain, reduce anxiety, and stimulate appetite in the same way that marijuana does, but without its psychoactive effects. CBD has also shown promise in treating certain types of seizures.
For this study, nine healthy men took either 600 mg of CBD or the same dose of a placebo. According to the researcher, those treated with CBD had lower blood pressure before and after exposure to stressful stimuli (including exercise or extreme cold).
Parihar V, Rogers A, Blain AM, Zacharias SRK, Patterson LL, Siyam MA. Reduction in Tamoxifen Metabolites Endoxifen and N-desmethyltamoxifen With Chronic Administration of Low Dose Cannabidiol: A CYP3A4 and CYP2D6 Drug Interaction. J Pharm Pract. 2020:897190020972208. View abstract.
Overview. GW Pharmaceuticals Web site. Available at: https://www.gwpharm.com/about-us-overview.aspx. Accessed: May 31, 2015.
Martin RC, Gaston TE, Thompson M, et al. Cognitive functioning following long-term cannabidiol use in adults with treatment-resistant epilepsy. Epilepsy Behav. 2019;97:105-110. View abstract.
Special Precautions and Warnings
Leweke FM, Piomelli D, Pahlisch F, et al. Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia. Transl Psychiatry 2012;2:e94. View abstract.
Casarotto PC, Gomes FV, Resstel LB, Guimaraes FS. Cannabidiol inhibitory effect on marble-burying behavior: involvement of CB1 receptors. Behav Pharmacol 2010;21(4):353-8. View abstract.
Bebee B, Taylor DM, Bourke E, et al. The CANBACK trial: a randomised, controlled clinical trial of oral cannabidiol for people presenting to the emergency department with acute low back pain. Med J Aust. 2021;214(8):370-375. View abstract.
Children: It is possibly safe for children to take a specific prescription CBD product (Epidiolex) by mouth in doses up to 25 mg/kg daily. This product is approved for use in children with certain conditions who are at least 1 year old. It isn’t clear if other CBD products are safe in children.