Because everybody's body is different, it's difficult, if not impossible, at this point to be 'scientific' about it.

In science, in order to prove something, the same result must be obtained over and over again. If it differs, it cannot be proven.

As results of giving medication to human beings are always different, depending on the person, there is no way it is scientific.

Some disciplines are sciences, i.e. they always have the same results. If you jump from a 60 storey building, you'll die. Gravity will ensure that.

Only the hard sciences can actually have that kind of proof - physics, chemistry, geology, etc.