Cannabidiol (CBD), one of the major constituents of the plant cannabis, has received increasing interest in the United Kingdom in recent years for valid reasons. Research has proven its broad range of therapeutic properties including anti-inflammatory, anticonvulsant, pain-relieving and anxiety-relieving among others, as well as its favorable safety and tolerability profile. Currently, CBD-containing medicinal products are in clinical trials for the treatment of various diseases, and Epidiolex - a pure plant-derived CBD - has been approved to be a therapy for two seizure disorders.
However, not everyone can acquire CBD safely from medical providers. Since it is not a controlled substance in the UK, CBD-based products are widely commercially available and increasingly popular, primarily in an oil format. A study into 29 most popular items in the UK from 27 brands has uncovered many issues in compositions of over-the-counter CBD products. First, the mean advertised CBD content is 4.5%, while the actual mean measured CBD content of products is significantly lower at 3.2%. Only 11/29 (38%) products have within 10% of the advertised CBD concentration. Second, 16/29 (55%) contain measurable levels of delta-tetrahydrocannabinol (THC) (with a mean content of 0.04%) or cannabinol (CBN) (with a mean content of 0.01%), as well as most other phytocannabinoid compounds including cannabidiolic acid (CBDA), cannabidivarin (CBDV), and cannabidivarin acid (CBDVA). It is important to note that THC and CBN are psychoactive components of cannabis and thus are classified as controlled substances, rendering products containing them illegal to possess. Altogether, these findings are warnings that the quality of many over-the-counter CBD-based products in the UK are substandard, especially with regards to CBD content and levels of illegal substances.