What is Beta-Ecdysterone (20-hydroxyecdysone) Ecdysterone (20-hydroxyecdysone) is a naturally occurring steroid found in plants, belonging to a family of compounds called ecdysteroids. What Does Ecdysterone Do Enhances Lean Mass Gains The primary reason ecdysterone (and ecdysteroids, in general) have received increasing amounts of interest in recent years is due to its anabolic (pro-muscle building properties). Several studies have demonstrated that ecdysterone is able to significantly increase muscle hypertrophy both in vitro and in vivo.