There's also a 2006 study that showed no effect in humans and a couple from the late 1980s that I can't find but which were described this way in the 2006 study that contradicted the results.
The most often cited scientific study on ecdysterone was published in Scientific Sports Bulletin by Simakin. This study sought to determine the effect of ecdysterone on muscle tissue mass and fat mass, while testing for hormonal changes in the subjects. Seventy-eight highly trained male and female athletes served as subjects in one of three experimental groups: protein, protein and ecdysterone