Reviews of the medical records of patients whose cancers were claimed to be reduced or cured after Laetrile treatment found insufficient medical evidence to judge Laetrile's efficacy. Finally, in a clinical trial in cancer patients reported in 1982, Laetrile neither caused shrinkage of tumors, nor increased survival time, nor alleviated cancer symptoms, nor enhanced well-being. Several reports in the medical literature document instances in which Laetrile has caused serious, life-threatening toxicity when taken in large doses in the manner prescribed by Laetrile advocates. In light of the lack of efficacy of Laetrile and its demonstrated ability to cause harm, Laetrile should not be used to treat cancer. ASHP A review of recent literature dealing with laetrile considering its sources, chemistry, metabolism, claims for efficacy, and toxicity, is presented.
Evidence shows laetrile is neither safe nor effective.
Laetrile may be a carcinogen and therapy may shorten the patient's life expectancy. ASHP A review of the literature on laetrile is presented covering its chemical composition and structure, proposed mechanism of action in the treatment of cancer, effectiveness, side effects and chronic intoxication, and the questionable lack of quality control observed in the analysis of the commercial samples of tablet and injectable preparations. The chemical composition and structure of amygdalin, prunasin, and mandelonitrile are also given. Evidence to date shows that laetrile is neither safe nor effective in the treatment of cancer. The great majority of these patients were in good general condition before treatment.