There are a few types of scientific experiments done on herbs and synthetic drugs, it is good to know the difference;
A) Ex vivo/ in vitro studies: These are done on isolated cell lines or alike. The results may not be relevant in humans. They are important for basic characterisation.
B) In vivo animal studies: These types of experiment are conduct on animals which researchers use to ‘model’ what the behavior of a herb would be in a human. Similar to ex vivo studies the results often do not replicate in humans, they are often cruel and ethically dubious.
C) Open label studies: These studies are bias because the patient and investigator both know they are receiving treatment, which gives rise to the placebo effect.
D) Single blind clinical trials: These are studies where the patients do not know whether they are getting a herb or a placebo.
E) Double blind clinical trials: These are studies where both the patients and investigator do not know whether they are giving herb or placebo.
F) Placebo controlled: In order to compare against something patients are given a placebo treatment so that statistical analysis may be done of the group receiving real treatment versus that receiving false treatment.
G) Alternate medication controlled: The same as placebo controlled, but a different medication is used such as a synthetic drug.
H) Randomised: Patients are allocated treatment or control at random. Checks must be performed to ensure both groups have a similar gender and age balance.
Additionally be aware that studies may suffer from low power, meaning if they have a small number of patients they are not as reliable as those with a very large number of patients. Most studies on herbal medicine are low powered or poorly controlled. The letter N refers to the number of people in a study.