Since the early 1950s, a modified form of amygdalin has been promoted under the names laetrile and "Vitamin B17" as a cancer cure, but it is not a vitamin and studies have found it to be ineffective and potentially toxic as a possible cause of cyanide poisoning.
Amygdalin was first isolated in 1830. In 1845 it was used as a cancer treatment in Russia, and in the 1920s in the United States, but it was considered too poisonous. In the 1950s, a purportedly non-toxic, synthetic form was patented for use as a meat preservative, and later marketed as laetrile for cancer treatment.The U.S. Food and Drug Administration prohibited the interstate shipment of amygdalin and laetrile in 1977.Thereafter, 27 U.S. states legalized the use of amygdalin within those states.
A glycoside, C20H27NO11, commonly found in seeds and other plant parts of many members of the rose family, such as kernels of the apricot, peach, and bitter almond, which breaks down into hydrocyanic acid, benzaldehyde, and glucose.
[From Late Latin amygdalus, almond tree, from Greek amygdalos.]