In the medical literature, the use of amygdalin / laetrile in the treatment of cancer is marked as »a typical example of quackery«.
Amygdalin / laetrile is not used in official medicine!
The metabolism of amygdalin produces hydrogen cyanide, which is a very strong poison. β-Glucosidase (one of the enzymes that catalyze the releasing of cyanide from amygdalin) is present in the small intestine, but also in many foods. The released cyanide can lead to unpredictable consequences or death of man, especially if you ingest it.
There are many examples in the medical literature describing the serious consequences of poisoning in patients who used amygdalin / laetrile to treat cancer.
Some proponents of the use of laetrile in medicine claim that the cyanide resulting from laetrile is immediately detoxified by the mitochondrial enzyme rhodanese into thiocyanate. These claims are wrong, primarily because the thiocyanate is also toxic (although less than cyanide). In addition, the body can only use a small amount of the enzyme present in the blood, regardless of its stock in the kidneys or liver. At the same time, the content of amino acid cystine and cysteine and other sulfur compounds dramatically decreases by the laetrile. Laboratory blood tests show large amounts of toxic cyanide in patients with laetrile.