No. Are all medicines safe? Remember that nightshade is a herb, so too is oleander both are very poisonous.
Some yes, some no. There are many herbal remedies, with varying characteristics, safety, & effectiveness. A good general resource for you is national center for complementary & alternative medicine: http://nccam.Nih.Gov/health/herbsataglance.Htm for integrative medicine physicians who can work with you personally on this: www.Azcim.Org or www.Holisticboard.Org; naturopathic docs: www.Naturopathic.Org.
Caveaet emptor. "herbal remedies" imported from overseas, especially asia, are often not what they are supposed to be. They are unregulated and you assume the risk.
Herbal Products. A lot of herbal products have not been tested for safety so you have to do some research of your own because a lot of docs are not up on herbs.