The short answer: compliant, carefully made products like CBD Supermarket products, are perfectly legal in the UK.
The long answer: The CBD industry is rapidly evolving and the regulations surrounding CBD are constantly changing to keep up. CBD (Cannabidiol) is legal in the UK to take as a food supplement, not for medicinal use. Selling CBD products is legal in the UK, providing they contain no controlled substances such as THC and come from an EU approved hemp strain. THC (Tetrahydrocannabinol) remains an illegal substance. Brands selling CBD products in the UK must have submitted a Novel Food Application by 31st March 2021.