[gus_massa]

Even with careful studies, there have been some awful messes. One famous example is Thalidomide: http://en.wikipedia.org/wiki/Thalidomide (If you are not impressionable you can use Google images.)

Some drugs investigations are discontinued because they cause complications or deaths in the small test groups. Another important number is how many additional dead could have been if everyone could take unapproved treatments.

And most people would sign whatever the doctor tells them to sign, for example a "NOT FDA APPROVED"-waiver. People thrust whoever has a white coat and promises a cure. There has been problems with peopled enrolled in official experimental drug test, that didn't understand the details, but had signed just another "usual" form handled by the doctors.

[dmm]

Thalidomide was extremely effective in treating morning sickness, it was just dangerous to fetuses.

Why does the Thalidomide tragedy justify the FDA testing for _effectiveness_?

[gus_massa]

Sorry, I couldn't remember something more relevant, like a pill for the heart that reduces the blood pressure but after some years it produces more strokes. But if no one test the new proposed drugs for effectiveness and side effects, then there would be more death and complications.