Herewith some cautions about Chinese Herbal Medicines. There's a popular notion that herbal medicines are safe because they are natural, they are plants, they aren't processed into a stronger and dangerously potent form. All of these are untrue of Chinese Herbal Medicines. Keep several things in mind if you're considering taking Chinese medicines. First, many natural things are toxic and lethal to humans.
Second, any substance used according to the principles of the medicine is an herb. In addition to plants Chinese herbs include wood, minerals, stone, and organ parts from humans and animals. It is true that only a handful of Chinese Medicine Herbs are toxic or lethal in a person taking no other supplements or pharmaceuticals.
Third processing of Chinese herbs produces changes in the properties of each herb and the combining of them also produces a whole entity with it's own properties. This is of course the reason for combining them.
There are some known interactions between Chinese Herbal Medicines but accurate sources are few. The most reliable material comes from research over the past 50 years in China where a vast amount of research into the pharmaceutical properties of herbs has been done. For instance, an herb named Dan Shen - Salvia which is used for Blood Stagnation has a very similar affect to the anticoagulants warfarin and coumadin. It's strong enough to require adjustment of the anticoagulant dosage. Another herb that affects pharmaceutical drugs is Ren Shen - Ginseng. It lowers blood glucose levels.
During the 1990s the US Food & Drug Agency banned a number of herbal medicines made in Mainland China because they contained pharmaceutical substances. This was not fraud. These formulas are still in use in China. The addition of pharmaceuticals in each medicine was considered an improvement of that medicine.
Chinese Herbal Medicines are a growing export market and Chinese growers have worked with their distributors in other nations to make their products meet the standards of each country. In the USA, herbal medicne producers have worked closely with the FDA to ensure compliance with FDA standards.
I hope that I have made it apparent that Chinese herbal medicine is just as as complex as pharmacology and that it requires years of education and training to prescribe not only effectively but safely. Please do not read a book, match your symptoms to it and take a Chinese medicine on that basis. It's unlikely that you'll experience more than significant discomfort (e.g. extreme diarrhea) but it is quite possible to do harm to yourself.