Herbal medicine refers to plants or plant ingredients that are used to maintain or improve health. The plants and the plant products are called herbs, herbal remedies, herbal medicinals, medicinal herbs, medicinal plants, and phytomedicinals.
The most popular herbal medicines include echinacea, thought to relieve cold symptoms; ginkgo and ginseng, sold to improve memory and alertness; and St.-John’s-wort, which may relieve mild depression. Some herbs used to flavor food in cooking may have medical uses. For example, garlic may reduce the risk of heart disease.
Hundreds of herbal medicines are sold in a variety of forms. They are sold as bulk (loose or unpackaged) plants, as parts of those plants, and as powders, capsules, tablets, liquids, and extracts. Bulk plants are used to prepare the other dosage forms. In some products, herbs are combined with nonherbal ingredients. Extracts contain a strong solution of some of the ingredients. Liquid extracts and pills are the most popular forms.
Many people view herbal medicines as milder or safer than other drugs, but some plants contain chemicals that are powerful drugs. In fact, about one-fourth of all prescription medicines come from plants.
The United States Food and Drug Administration (FDA) classifies herbal medicines as separate from nonprescription and prescription medicines. An herbal remedy is considered a dietary supplement, a product that is taken in addition to a normal balanced diet but is not a food or drug. Dietary supplements do not have to meet FDA rules for safety, effectiveness, and quality.
Scientists continue to research the safety and effectiveness of herbs. Even though herbal medicines are natural, they may cause side effects. Because herbal medicines act differently in different people, it is important to consult a doctor or pharmacist when taking them. The strength of the active ingredients in an herbal remedy may vary depending on how the plant is grown, harvested, stored, and prepared. Unwanted effects may result from an allergy, an impurity in the product, an interaction with other drugs, a misidentification of the plant, or a wrong dose. While the benefit of some herbal medicines may outweigh the risks, for some people the risks may be too high or unknown. Scientists are investigating the active substances, best doses, and right ingredients of herbal medicines as well as the effects that other medicines or food may have on them.
