Prescription pills, that is. 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're supposed to? Afterwards, you can stick around with BBC2 for the second episode of The Persuasionists, or you could check out TV3's instalment of Midweek: Cults - How Safe Are Your Children.