Most cannabinoids are illegal in the United Kingdom and are listed as such under the Misuse of Drugs Act. However, the United Kingdom has legalized CBD, so long as it is derived from an industrial hemp strain approved by the European Union. To be used in the United Kingdom, it cannot contain more than 0.2% THC.
It also appears that CBD is becoming mainstream as a product. According to an article by Weed Maps, health food store chain Holland & Barrett has started offering supplements, drops, creams, and other products infused with CBD. Further, the article notes a recent study by Brightfield Group, a marketing firm based in Chicago that estimates that the European CBD market is valued at $318 million and that by 2023, it is estimated that it will grow by 400%.