 Julian's research at Glidden changed direction in 1940 when he began work on synthesizing progesterone, estrogen, and testosterone from the plant sterols stigmasterol and sitosterol, isolated from soybean oil by a foam technique he invented and patented. At that time clinicians were discovering many uses for the newly discovered hormones. However, only minute quantities could be extracted from hundreds of pounds of the spinal cords of animals.
