Social scientists & certainly economists tend to look up to medical research, partly because its where the money is, and also because one of its key methods, the randomized control trial, is seen by many as providing a "gold standard" when it comes to measuring treatment effects - though Deaton, Heckman and others have questioned whether RCTs in economics should enjoy this privileged status.
The public generally tend to hold medical research in even higher respect. Medical researchers are good people, passionately if objectively, pushing back the frontiers of knowledge to help make us better.
So how worrying would it be if much medical research was actually wrong? This conclusion has been emerging from the work of a Greek medical researcher, John Ioannidis, and his team. The causes of this problem are various, including publication bias, and are well known but the scale of the problem is probably not. This article may make you distinctly uneasy.
Part of the problem, that key studies have not been replicated and may be wrong, is not peculiar to medicine. It may well plague the social and behavioural sciences too. This article on the subject won't make you feel any better.