Ernst Theodore Krebs Jr. (May 17, 1911 – September 8, 1996) was an American promoter of various substances as alternative cures for cancer, including pangamic acid and amygdalin.

He also co-patented the semi-synthetic chemical compound closely related to amygdalin called laetrile, which was also promoted as a cancer preventative and cure.

He ultimately received a Bachelor of Arts degree from the University of Illinois, after failing science courses at the various colleges.

Krebs was the director of the John Beard Memorial Foundation where he promoted fraudulent claims about a laetrile cancer remedy.

[12] Amygdalin, C20H27NO11, is a glycoside initially isolated from the seeds of a cultivar of the almond tree, Prunus dulcis var.

It was promoted in a modified form called laetrile as a cancer cure by Ernst T. Krebs, Jr. under the name "Vitamin B17", but studies have found it to be ineffective.