Although wild yams and soy are traditionally regarded as foods rich in progesterone, merely eating these types of food does not increase progesterone levels in the body. As of 2015, there are no foods that naturally promote progesterone production in humans, as claimed by Dr. Gerard Honore, a fertility medicine specialist at HealthTap.
Progesterone is a female hormone that is naturally produced in the body. It can also be synthesized in a laboratory in the form of progestin, which induces the same effects as progesterone, as stated by the University of Maryland Medical Center.
Wild yams and soy contain a compound called diosgenin, which is processed in the laboratory and transformed into pregnenolone and then progesterone. Humans, however, cannot stimulate enhanced levels of progesterone through the consumption of yams and soy because they lack the mechanism for converting diosgenin into progesterone, according to WebMD.