Red clover is the dried flower head of a member of the pea family widely grown as animal fodder and found in temperate climates through the world. It is native to Europe and naturalized throughout the United States.
Red clover is mentioned as a blood purifier, diuretic, general tonic, and folk cancer remedy in Jethro Kloss's Back to Eden. The flower has been used as a folk remedy to relieve spasms associated with asthma and bronchitis and to treat skin sores or ulcerations. It is one of the ingredients of the controversial Hoxsey formula used at alternative cancer clinics in Mexico.
Red clover's use as a cancer remedy is not backed by any clinical studies in humans. Pharmacological studies even in animals are few. Red clover does, however, contain an interesting group of compounds called isoflavones, including genistein, diadzen, and biochanin A, among others. James A. Duke has suggested red clover as a good candidate for further examination as a chemopreventive, a dietary substance that may help prevent cancer. Epidemiological studies provide evidence that certain dietary components can have a significant effect on the incidence and location of cancers in humans. For example, some members of the mustard family, especially broccoli, are known to help prevent the development of cancers, an effect attributed to free-radical scavenging properties. The flavonoid genistein (mostly extracted from soybeans) is now available in dietary supplements known as nutraceuticals. A recent preliminary laboratory study found that biochanin A inhibited the activation of cancer in cell cultures. More research on red clover and its isoflavones is clearly warranted.
Dried red clover tops are generally used in teas, as well as in capsules, tablets, and various combination products.
No side effects have been reported from using this herb. However, cattle ingesting late season or spoiled red clover hay have developed symptoms such as frothing, diarrhea, dermatitis, and decreased milk production. It is possible that similar effects would occur in persons using fermented or otherwise spoiled red clover.