Herbert Leonard Ley Jr. (September 7, 1923 – July 22, 2001) was an American physician and the 9th Commissioner and head of the U.S. Food and Drug Administration (FDA).

From 1951 until 1958, he worked with the Army Medical Service Graduate School in rickettsial disease research, the Office of the Surgeon General, and as an epidemiologist in Korea and Vietnam.

An artificial sweetener, it was originally brought to market as a flavoring ingredient in drugs, but in 1958, it was designated GRAS (generally recognized as safe) and its uses expanded, first into table sugars, then into many foods.

However, by that time some animal studies had shown that very high doses of cyclamates, at levels of humans ingesting 350 cans of diet soda per day, led to higher rates of bladder cancer in rats.

In October 1969, Department of Health, Education & Welfare Secretary Robert Finch bypassed Ley and the FDA, and removed the GRAS designation from cyclamate, banning its use in general purpose foods but keeping it available for restricted use in dietary products with additional labeling.

[1]: 24 [4][8][9][10] In accepting Ley's resignation, Secretary of HEW Finch praised him as a "gifted scientist and a dedicated public servant," saying that he had "coped strenuously with an unwieldy agency".

I respect Herb Ley; he was very different that either George P. Larrick or James L. Goddard [Previous FDA Commissioners], but I'm convinced he was dedicated to the best interests of the American public.

And indeed, I believe that he got into significant trouble during his last days in the agency during the fall of 1969, in connection with the banning of cyclamates because he did what the Secretary told him to do (to not discuss the matter within the FDA).