laetrile

Laetrile is the trade name for a preparation that contains amygdalin, a cyanogenic glycoside found in seeds such as apricot kernels, bitter almonds, peaches, and apple seeds. Although it has been marketed as vitamin B17, laetrile is not recognized as a vitamin and has not been shown to provide a medical benefit for cancer.

History and use

Laetrile was developed and promoted in the mid-20th century by proponents including Ernst T. Krebs Jr. It gained prominence in the United States and other countries as an alternative cancer treatment, often sold through clinics and supplement-like outlets. It remains controversial and is not accepted by mainstream oncology.

Mechanism and evidence

Proponents have claimed that laetrile releases cyanide preferentially in cancer cells, thereby killing malignant tissue while sparing healthy cells. This proposed mechanism is not supported by reliable scientific evidence, and there is no proven improvement in cancer outcomes from laetrile treatment. Large reviews and controlled clinical trials have found no significant benefit.

Safety and regulation

Laetrile can release hydrogen cyanide, which poses risks of serious poisoning. Adverse effects range from nausea and headaches to hypotension, coma, and death. Because it has not demonstrated efficacy, it is not approved as a cancer treatment by major health authorities. In the United States, laetrile has been restricted or prohibited for interstate commerce as a drug, and many other countries regulate or discourage its use.

Current status

Laetrile remains a focal point in discussions of alternative cancer therapies. It is generally regarded by the medical community as ineffective and potentially dangerous, and authoritative health organizations discourage its use outside of approved clinical contexts. Some supporters continue to advocate for laetrile, often citing anecdotal reports rather than robust clinical evidence.