Nitriloside is a generic term for beta-cyanophoric glycosides, a large group of water-soluble, sugar-containing compounds found in a number of plants. Amygdalin (also called laetrile), is one of the most common nitrilosides. Amygdalin is found in the seeds of many fruits, particularly apricots, as well as in grains and grasses.
A patented form of the compound, also called Laetrile®, is a partly man-made molecule and shares only part of the amygdalin structure. Both Laetrile® and amygdalin have been promoted and sold as "vitamin B-17", although neither compound is a vitamin.
Chinese medicine practitioners have used apricot seed as a treatment for respiratory diseases, including bronchitis and emphysema. It is believed to suppress coughs and to help remove mucus. The oil has also been used as a laxative. Small amounts are said to stimulate breathing, improve digestion, and give a sense of well-being. It has also been used to treat rheumatic disease in Germany and high blood pressure in both Germany and the United States.
Laetrile® has been used as a cancer treatment. It was first used for this purpose in Russia in 1845 and later in the United States and Mexico. More recently, the American Cancer Society (ACS) has stated that the use of Laetrile® or amygdalin to treat cancer is not supported by the available scientific evidence. The ACS warns that these compounds may be converted to cyanide in the body. A number of cases of cyanide poisoning associated with Laetrile® have been reported. The National Institutes of Health (NIH) has similarly reported that clinical evidence has shown laetrile to be of little benefit against cancer and that its side effects resemble those of cyanide poisoning.
Laetrile® and amygdalin are not approved by the U.S. Food and Drug Administration (FDA) as a treatment for cancer.

Related Terms

Amygdalin, Armeniaca vulgaris, apricock, apricot kernel, apricot kernel oil, apricot oil, apricot pits, apricot seed, benzaldehyde, cyanophoric glycosides, hydrocyanic acid, ku xing ren (Chinese), Laetrile®, mandelonitrile, mandelonitrile beta-D-gentiobioside, mandelonitrile-beta-glucuronide, prunasin, Prunus (genus), semen Pruni armeniacae, vitamin B17, xìng rén (Chinese).

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Cancer (Grade: D)
Reliable scientific evidence supporting the safe and effective use of laetrile as a treatment for cancer is currently lacking. Studies have also found laetrile treatment to be toxic.