Dr Chris van Tulleken has been working in a GP surgery in east London for weeks trying to treat specially selected patients without drugs. Now he wants to use what he's learnt to supersize his social experiment and offer drug-free treatments to all 14,000 patients at the practice.

When no-one turns up to his drug-free clinic, Dr Chris learns that patients just want a quick fix - people are busy and they prefer to pop a pill than motivate themselves to make lifestyle changes.

But with hard marketing from the receptionists, Chris finally gets a new patient. Crystal is taking 30 pills a day for extreme chronic pain in her back. Things have got so bad that she can't leave her house without a neck brace and a back corset. Over the course of five months, with a dramatic process of withdrawal from her addictive meds, Chris leads her on an extraordinary road to recovery.

Meanwhile, another patient, Sarah, is struggling to complete her drug-free therapy. She's been taking antidepressants for the last eight years, and Chris is hoping that cold-water swimming will steady her mood sufficiently to come off them. But a series of tearful phone calls show Chris that giving up her medication won't be easy. He will need to find a completely new strategy to help this young mum go drug free. While working with Sarah, he discovers that one of the most common tools to diagnose depression - a questionnaire - is developed by a drugs company who make drugs that treat depression.

Back at the surgery, Chris discovers the close relationship between the pharmaceutical industry and GPs is everywhere. He attends a practice lunch that is sponsored and paid for by a drugs company. Dr van Tullekkan believes this is a 'total disgrace' and 'a simple bribe'. He engages in a series of confrontations with the GPs and representatives from the pharmaceutical industry to try to put a stop to the drug-sponsored lunches. But can he pull it off?

Before he leaves the practice, he comes up with one final experiment. Thousands of patients at the surgery are taking drugs to reduce their risk of a heart attack or stroke. Dr Chris has discovered evidence for a miracle alternative cure - walking! The group is not impressed with his simple idea but finally agree to take part. Over eight weeks he asks them to take a brisk walk for thirty minutes, five times a week. The final results are impressive, but will it be enough to keep them off the meds and ultimately convince the doctors to continue the group once he's gone? Show less