How do you know a drug is safe and effective? Because it’s tested against a placebo, or sugar pill, and you know it works if it significantly outperforms the dummy pill. But suppose the sugar pill isn’t as benign as we think – suppose it contains a chemical that makes even a bad drug look good? The trouble is, nobody has checked – until now.

Finally, researchers have started to take a look at the placebo, a method used in countless drug trials over the years. A research team from the University of California’s school of medicine in San Diego scanned four of the major medical journals published in 2008 and 2009 – and discovered that hardly any trials listed the ingredients of the placebo.

As the composition of the placebo can have a big effect on a drug trial’s results, its ingredients should be listed every time, they say.

(Source: Annals of Internal Medicine, 2010; 153: 532-5).

via Why drugs are not as effective – or safe – as they’re telling us | What Doctors Don’t Tell You.