More than one billion prescriptions are handed out by GPs every year in the UK. The overuse of prescription drugs is one of the biggest problems the country faces. In the final episode of this two-part experiment, Dr Chris van Tulleken asks whether people really need the medication they’ve been prescribed.

First, however, Chris looks at the way that some pharmaceutical companies encourage GPs to prescribe their drugs. He also faces an uphill struggle trying to persuade people that in some situations exercise can be just as effective as the quick fix of popping a pill.

And when he does get one chronic-pain sufferer to try kung fu, the results are astonishing.