One of the most remarkable features of the Laetrile controversy is its persistence. Although public attention and support of Laetrile treatment clearly reached a peak in the 1970s, Laetrile has a long and colorful history in the United States. Attempts to resolve the controversy surrounding it have been numerous and strikingly unsuccessful. In 1953 the Cancer Commission of the California Medical Association issued a document that concluded that “no satisfactory evidence has been produced to indicate any significant cytotoxic effect of Laetrile on the cancer cell.” Ten years later the Cancer Advisory Council to the director of California's Department of Public Health issued a report that found that Laetrile was of “no value in the diagnosis, treatment, alleviation or cure of cancer.” Upon the council's recommendation, in 1963 the California Department of Health banned the treatment of cancer with Laetrile.

Agencies of the federal government have also attempted to bring closure to the Laetrile controversy. As early as 1960, the Food and Drug Administration (FDA) conducted seizures of Laetrile and banned its shipment in interstate commerce. The FDA's right to regulate Laetrile was, however, challenged in a series of court cases in the late 1970s. As part of that controversy, the FDA commissioner, in a lengthy 1977 decision, ruled that Laetrile is not generally recognized by qualified experts as a safe and effective cancer drug and that it is not exempt from FDA regulation. Despite this decision, a judge issued a permanent injunction forbidding the FDA from restricting the importation and use of Laetrile.