The complex metabolism of poststerone in male rats.

Ecdysteroids are not endogenous to mammals, but are normal components of the food intake of many mammalian species consuming phytoecdysteroid-containing plants. The most frequently encountered phytoecdysteroid is 20-hydroxyecdysone (20E). Several pharmaceutical effects have been observed after ecdysteroid injection or ingestion, but it is not clear to what extent metabolites generated in the mammalian body contribute to these effects.