A Guide to Common Medicinal Herbs

Here are some common medicinal herbs. Most herbs have not been completely tested to see how well they work or to see if they interact with other herbs, supplements, medicines, or foods. Products added to herbal preparations may also cause interactions. Be aware that "natural" does not mean "safe." It's important to tell your healthcare providers about any herb or dietary supplement you are using.
Medicinal plants, also called medicinal herbs, have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including defense and protection against insects, fungi, diseases, and herbivorous mammals.

“Chamomile”

Considered by some to be a cure-all, chamomile is commonly used in the U.S. for anxiety and relaxation. It is used in Europe for wound healing and to reduce inflammation or swelling. Few studies have looked at how well it works for any condition. Chamomile is used as a tea or applied as a compress. It is considered safe by the FDA. It may increase drowsiness caused by medicines or other herbs or supplements. Chamomile may interfere with the way the body uses some medicines, causing too high a level of the medicine in some people. Chamomile for the skin (topical) may be used to treat skin irritation from radiation cancer treatments. Chamomile in capsule form may be used to control vomiting during chemotherapy.

“Echinacea”

Echinacea is commonly used to treat or prevent colds, flu, and infections, and for wound healing. Many studies have looked at how well echinacea works to prevent or shorten the course of a cold, but none were conclusive. Some studies do show some benefit of using echinacea for upper respiratory infections. Short-term use is advised because other studies have also shown that long-term use can affect the body's immune system. Always check with your healthcare provider about any interactions with medicines that you are already taking. People allergic to plants in the daisy family may be more likely to have an allergic reaction to echinacea. The daisy family includes ragweed, chrysanthemums, marigolds, and daisies.

“Feverfew”

Feverfew was traditionally used to treat fevers. It is now commonly used to prevent migraines and treat arthritis. Some research has shown that certain feverfew preparations can prevent migraines. Side effects include mouth ulcers if the leaves are chewed and digestive irritation. People who suddenly stop taking feverfew for migraines may have their headaches return. Feverfew should not be used with nonsteroidal anti-inflammatory medicines because these medicines may change how well feverfew works. It should not be used with warfarin or other anticoagulant medicines.

“Saint John's wort”

Saint John's wort is used as an antidepressant. Studies have shown that it has a small effect on mild to moderate depression over a period of about 12 weeks. But it is not clear if it is effective for severe depression. A side effect is sensitivity to light, but this is only noted in people taking large doses of the herb. St. John's has been shown to cause dangerous and possibly deadly interactions with commonly used medicines. It is very important to always talk with your healthcare provider before using this herb.

“Gingko”

Ginkgo leaf extract has been used to treat a variety of conditions such as asthma, bronchitis, fatigue, and tinnitus. It is also used to improve memory and to prevent dementia and other brain disorders. Some studies have supported its slight effectiveness. But exactly how gingko works isn't understood. Only extract from leaves should be used. Seeds contain ginkgo toxin. This toxin can cause seizures and, in large amounts, death. Because some information suggests that ginkgo can increase the risk of bleeding, it should not be used with nonsteroidal anti-inflammatory medicines, anticoagulants, anticonvulsant medicines, or tricyclic antidepressants.

“Ginseng”

Ginseng is used as a tonic and aphrodisiac, even as a cure-all. Research is uncertain how well it works, partly because of the difficulty in defining "vitality" and "quality of life." There is a large variation in the quality of ginseng sold. Side effects are high blood pressure and tachycardia. It's considered safe by the FDA. But it shouldn't be used with warfarin, heparin, nonsteroidal anti-inflammatory medicines, estrogens, corticosteroids, or digoxin. People with diabetes should not use ginseng.