Cannabis oil, which is also known as cannabidiol (CBD), is now available to buy in the UK in pharmaceutical shops. According to the Cannabis Trades Association UK the number of CBD users has doubled from 125,000, 12 months ago, to 250,000 now. It has been claimed that it can be beneficial in treating a number of health care issues including pain, symptoms of cancer and stress and anxiety. But what is cannabis oil made from and what is it used for? Here's everything you need to know.