Recent years have seen a step-change in Britain's drug culture. Out go the 'old' illegal drugs, cocaine, heroin, speed - swept to one side by a younger generation who can get their hits not only more cheaply but also legally. There is burgeoning market for drugs specially designed by clandestine chemists to get around Britain's drug laws. The new drugs are legal to buy because they're sold as research chemicals and labelled 'not for human consumption'. This hard-hitting observational documentary, Legally High - directed by triple BAFTA-award winner Dan Reed, takes a trip into the murky world of legal drugs, where underground chemists invent new drugs faster than the government can legislate against them.

• Documentary