The previous subject is obviously an endless one, but as this is the glossary of an herb book, let me assure you, virtually no plants have a direct steroid hormone-mimicking effect. There are a few notable exceptions with limited application, like Black Cohosh and Licorice. Plant steroids are usually called phytosterols, and, when they have any hormonal effects at all, it is usually to interfere with human hormone functions B-sitosterol, found in lots of food, interferes with the ability to absorb cholesterol from the diet. Com oil and legumes are two well-endowed sources that can help lower cholesterol absorption. This is of only limited value, however, since cholesterol is readily manufactured in the body, and elevated cholesterol in the blood is often the result of internal hormone and neurologic stimulus, not the diet. Cannabis can act to interfere with androgenic hormones, and Dandelion phytosterols can both block the synthesis of some new cholesterol by the liver and increase the excretion of cholesterol as bile acids; but other than that, plants offer little direct hormonal implication.
The classic method of synthesizing pharmaceutical hormones involved using a saponin, diosgenin, and a five-step chemical degradation, to get to progesterone, and another, using stigmasterol and bacterial culturing, to get to cortisol. These are chemical procedures that have nothing to do with human synthesis of such hormones, and the plants used for the starting materials-Mexican Wild Yam, Agave, and Soybeans-are nothing more than commercially feasible sources of compounds widely distributed in the plant kingdom. A clever biochemist could obtain testosterone from potato sterols, but no one would be likely to make the leap of faith that eating potatoes makes you manly (or less womanly), and there is no reason to presume that Wild Yam (Dioscorea) has any progesterone effects in humans. First, the method of synthesis from diosgenin to progesterone has nothing to do with human synthesis of the corpus luteum hormone; second, oral progesterone has virtually no effect since it is rapidly digested; and third, orally active synthetic progesterones such as norethindrone are test-tube born, and never saw a Wild Yam.