Astragalus, also known as huang qi, is a perennial herb native to Northern China, Japan, Tibet, and Korea, where it grows in grasslands and well-drained woodlands. A member of the legume family, astragalus grows up to 1 meter in height with rigid stalks that sprout eight to twelve pairs of leaflets. The plant has small yellow blossoms, and bears its seeds in short, pea-like pods. The root of the plant, which has a fleshy, pale yellow center with a sweet, licorice-like flavor, is used for health purposes.
Astragalus root contains a variety of compounds including isoflavones and other flavonoids, polysaccharides, astragalosides, essential fatty acids, saponins, beta-sitosterol, betaine, and choline. Astragalus extracts are commonly standardized for isoflavone content.
In traditional Chinese medicine, the daily recommendation is a decoction made from 9 to 15 grams of the dried root. Astragalus root capsules are commonly taken in doses ranging from 2 to 3 grams per day. For standardized extracts, 1,000 mg per day is a common recommendation. Astragalus is not associated with any toxicity in this dosage range. Astragalus should not be used by organ recipients taking antirejection drugs, as it may interfere with the drugs' activity.