The historical record and modern research indicate that the herbs most often used for healthcare have an exceptional safety record. However, adverse events can occur after using any active substance. Side effects that have occasionally been reported after using herbs include headaches, skin rashes and digestive upsets. Such effects generally resolve rapidly, especially if the dosage is reduced or the herb is stopped. Allergic reactions are also very rare but have been reported, usually in individuals with contact allergy to specific plants.
Although speculative interactions between herbs and drugs are sometimes publicized, confirmed cases are rare. Nevertheless, some prescribed drugs are very strong and have a narrow range of safe dosage, which makes any interaction more risky. It is the responsibility of the clients to disclose fully any medications currently in use, including other herbs and supplements, so that they can be offered informed advice. Clients also are expected to inform their physicians of any herbs or supplements they are using. Any suggestion that the effect of a drug is being altered by simultaneous use of an herb should be reported directly to all health professionals involved. It is also advisable to stop taking herbs at least 48 hours before surgical operation, and in the event of being prescribed anticoagulants, antiepileptic drugs, and digoxin until expert advice is received.
At the Maryland University of Integrative Health safety is paramount, and it is our business to stay current with the literature on herbal safety. We will not expose clients to plant doses known to have toxic effects. The organs that are most vulnerable to any potent substances are the liver and kidneys, and it will be important for the client to divulge any previous history of disease in either of these organs. Herbs also should not be used in pregnancy or lactation without expert advice, and clients who become pregnant should stop taking herbs until advice is received.