traveltech_sara said:

It is worth asking what the claim would look like if it were false.

Adding the part of the answer the thread has not reached. It helps to ask what evidence would change your mind before you look at any. If nothing would, the discussion is not about evidence, and it is better to say so early than to spend nine posts discovering it.

The figures, for anyone assembling their own picture. Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a trend.

A narrower follow-up, since the general answer is now clear:

How long did you give it before you decided it was working?

Found this through search years later and it is still the best discussion of the question, so adding one thing. Say what you would expect to see if you were wrong, before you look. It is a small discipline and it changes what you notice.

Ask again with the specifics and you will get a better answer than this one.

wendy_avl said:

Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a…

True, and it depends on a baseline nobody has stated. Without knowing where someone started, the same number can be an excellent result or a disappointing one.