My Null hypothesis:

I am interested in testing the null hypothesis of no difference between effective time of drug use for herbal medicine and manufactured medicine. That is to say herbal drugs do not produce the outcome of interest with the same pace as manufactured drugs - such as the case control trial on trekkers, regarding the effects of Ginko on acute mountain sickness. I have tested my hypothesis on myself, and have paid prolonged attention to this process that found effects of natural medicine are rather preventive, encompassing, long lasting, but moderate. Hence, my disapproval about the results inferred from the trial mentioned below!

Randomised, double blind, placebo controlled comparison of ginkgo biloba and acetazolamide for prevention of acute mountain sickness among Himalayan trekkers: the prevention of high altitude illness trial (PHAIT)
http://www.bmj.com/cgi/content/full/328/7443/797