1,324 Soybean Seed Medicinal The fermented seed is weakly diaphoretic and stomachic. It is used in the treatment of colds, fevers and headaches, insomnia, irritability and a stuffy sensation in the chest. Soybean is listed as a major starting material for stigmasterol, once known as an antistiffness factor. Sitosterol, also a soy by-product, has been used to replace diosgenin in some antihypertensive drugs. 8,432