Part of this response could be explained by the way that CBD acts in the brain. In low doses, CBD may act as an agonist to several receptor sites, meaning it acts similarly to surrounding molecules that normally bind to the receptor, enhancing the signalling of those receptor sites. At higher doses, however, too much activity at the receptor site can lead to an opposite effect, negating the beneficial effects of CBD.
Outside of these two disorders, CBD’s effectiveness in treating seizures is uncertain. Even with Epidiolex, it is uncertain whether the anti-seizure effects can be attributed to CBD or some other factor.
CBD shows promise in the treatment of anxiety disorders, suggests a 2015 review of studies in the journal Neurotherapeutics. According to the investigators, CBD demonstrated potent anxiolytic (anxiety-relieving) effects in animal research, albeit with counterintuitive results.
CBD oil should be avoided during pregnancy and breastfeeding. A 2018 study from the American Academy of Pediatrics warned women to avoid marijuana during pregnancy due to the potential risks to a baby’s development. Although it is unclear how CBD contributes, CBD is known to pass through the placental barrier.
According to a 2017 study in the Journal of the American Medical Association, only 30.95% of CBD products sold online were correctly labeled. Most contained less CBD than advertised, while 21.43% had significant amounts of THC.
A review and meta-analysis of 8 studies with low-quality evidence of cannabis-based medicines found that they were better at reducing sleep problems compared to inactive medicines (placebo).
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.
A recent Gallup poll found 1 in 7 adults in the U.S. have used CBD. Does it help?
Does Topical CBD Help with Pain?
Cannabinoid receptors are part of the complex endocannabinoid system (ECS). It regulates the release of neurotransmitters (chemicals that communicate between nerve cells) in the brain, as well as in other parts of the nervous system. The ECS responds to both types of cannabinoids, phyto- and endo-.
Observational studies and randomized controlled trials (RCTs) of the effectiveness of cannabinoids in chronic noncancer pain found a 30% reduction in pain in 1 out of 3 of those using cannabinoids. This was considered significant.
Applications of transdermal cannabidiol were studied in people with temporomandibular (joint of the jaw) disorders (TMD) that caused myofascial (coverings of muscle) pain. Those studied had less muscle activity and pain after applying the topical CBD for 2 weeks.
Studies of CBD are ongoing, but some benefits have been found.