Second , you must use good judgment . There are many very serious conditions that you would not want to try to treat yourself by any means. You should always consult with your regular physician if you suspect you have something which may be serious, and you should always keep your physician informed about any herbal medicines or products you may be using. Third , and this reflects my personality, preferences and background - don't take advice from books that aren't referenced and documented to legitimate sources. These are signs of poor scholarship at the least.
Some people react differently to any drug due to their genetic make-up.
Some drugs are not appropriate if you might be pregnant. Some drugs will either diminish or enhance the action of other drugs you might be taking. So, having said all that, here are some books which I believe to be good places to educate yourself in preparation for taking medicinal herbs. These monographs were prepared by a panel of experts using the best research studies available at the time . That's important to remember, because a lot of research has been conducted in this field in recent years which would presumably alter the Commission E's conclusions in at least some cases.