Over a person's lifetime they are likely to be prescribed more than 14,000 pills. Antibiotics, cholesterol lowering tablets, anti-depressants, painkillers, even tablets to extend youth and improve performance in bed. These drugs perform minor miracles day after day, but how much is really known about them? Drug discovery often owes as much to serendipity as to science, and that means much is learnt about how medicines work, or even what they do, when they're taken. By investigating some of the most popular pills people pop, Horizon asks, how much can they be trusted to do what they are supposed to?

Dr Michael Mosley and Professor Alice Roberts investigate if male and female brains really are wired differently. New research suggests that the connections in men and women's brains follow different patterns, patterns which may explain typical forms of male and female behaviour. But are these patterns innate, or are they shaped by the world around us?" Using a team of human lab rats and a troop of barbary monkeys, Michael and Alice test the science and challenge old stereotypes. They ask whether this new scientific research will benefit both men and women - or whether it could drive the sexes even further apart.

More than a decade ago, scientists announced that they had produced the first draft of the human genome, the 3.6 billion letters of our genetic code. It was seen as one of the greatest scientific achievements of our age, a breakthrough that would usher in a new age of medicine. Find out how close we are to developing the life-changing treatments that were hoped for". Follow three people, each with a genetic disease, as they go behind the scenes at some of Britain's leading research labs to find out what the sequencing of the human genome has done for them - and the hope this remarkable project offers all of us.

The documentary 'The Knowledge of Healing' is an illuminating examination of Tibetan medicine, a practice which has developed over two millennia into a modern day successful method of healing that rivals western medical practices. Unlike Western medicine, based on biochemistry, Tibetan medical thinking (which is strongly rooted in Buddhist principles) views the human body as governed by an elaborately organized system of energies flowing through a network of channels. In the 12th century, the Gyüshi (Knowledge of Healing) was created, a text codifying this intricate system. The medications used comprise herbs, roots, minerals, etc. After flourishing for centuries, most Tibetan medical schools were destroyed by the Chinese in the 1950's and 1960's, and many physicians were executed. Speaking from exile, the Dalai Lama argues for the value of Tibetan medicine, while his personal physician Dr. Tenzin Choedrak describes the principles behind it. We follow physicians in India and Siberia treating patients for a variety of ailments from paralysis to heart disease, and meet researchers in Israel and Switzerland to see how western clinical studies are testing the effectiveness of Tibetan medicine.

Of all the wonders of the human body, there's one more mysterious than any other. Blood: five precious litres that keep us alive. Yet how much do we really know about this sticky red substance and its mysterious, life-giving force? Michael Mosley gives up a fifth of his own blood to perform six bold experiments". From starving it of oxygen to injecting it with snake venom, Michael reveals the extraordinary abilities of blood to adapt and keep us alive. Using specialist photography, the programme reveals the beauty in a single drop. Michael even discovers how it tastes when, in a television first, he prepares a black pudding with his own blood. Down the ages, our understanding of blood has been as much myth as science, but Michael reveals there might be truth in the old vampire legends, as he meets one of the scientists behind the latest research that shows young blood might be able to reverse the ageing process - the holy grail of modern medicine.

Cannabis is the world's favourite drug, but also one of the least understood. Can cannabis cause schizophrenia? Is it addictive? Can it lead you on to harder drugs? Or is it simply a herb, an undervalued medicine? Addiction specialist Dr John Marsden discovers that modern science is finally beginning to find answers to these questions. John traces the cannabis plants' birthplace in Kazakhstan; finds the origins of our sensitivity to cannabis in the simple sea squirt; and finds out just what it does to our brains. He meets people who have been changed by this drug in drastically different ways - from those whose lives have been shattered to those who lives have been revived.