syn. 20-hydroxyecdysone syn. isoinokosterone
Ecdysterone (20-hydroxyecdysone) is a steroid hormone involved in development and reproductive function in arthropods, a category of invertebrates. It is most widely identified as an insect hormone, where it plays a prominent role in molting (the technical term for molting is ecdysis). Ecdysterone belongs to a large family of related chemicals known as ecdysteroids. These compounds are structurally distinct from human steroid hormones, and are not known to bind the human androgen receptor. Ecdysteroids are also found in many plant species (phytoecdysteroids), presumably as part of an evolved defense mechanism that disrupts the reproductive system of pest insects. Plant extracts are the primary source for supplemental ecdysteroids, although synthetic manufacturing techniques are also known.
Although ecdysterone is an invertebrate hormone, it has been shown to exhibit some biological activity in mammals. The exact nature of this activity, however, remains unclear. Animal studies have demonstrated a diverse set of potential properties.309 This includes the support of reproductive functioning, nervous system functioning, heart and circulatory health, liver detoxification, immunity, and kidney function. Ecdysterone also appears to have some influence over cell proliferation, as well as protein, carbohydrate, and lipid metabolism. When noted, the associated changes in metabolism are generally positive, such as a lowering of blood sugar, increased synthesis of protein, and a reduction in serum cholesterol.
While ecdysterone has been the subject of animal investigations for more than 40 years, the therapeutic value of this substance in humans remains unknown. Since this hormone is known to have some biological activity in humans, it would not be surprising to see some medical applications further substantiated. Progress in this area, however, has been surprisingly slow. There is much speculation that the growth promoting effects of this compound in animals may also translate into increased exercise performance in humans, perhaps even leading to greater gains in muscle mass and strength. Presently, however, there are no peer-reviewed studies conclusively demonstrating such activity.
Ecdysterone is promoted to help increase muscle mass, strength, and anaerobic endurance.
The use of ecdysterone as a sport supplement is supported by animal data only. Its Clinical Support Rating is 2 (2/5).
Ecdysterone has been the subject of many studies, particularly in Eastern Europe. Positive changes have been reported in a number of animal experiments, which might translate to exercise performance benefits in humans. For example, one set of studies demonstrated that untrained rats given ecdysterone for 20 days had more exercise endurance than unsupplemented animals.310 Another study showed increased muscle adenosine triphosphate levels (a form of stored energy) in vitamin D deficient rats given ecdysterone.311 Other studies have shown increased bodyweight in pigs312 and quails313 fed diets enriched with this phytoecdysteroid. Sport supplement manufacturers commonly reference three additional Russian studies on ecdysterone. One study demonstrated a 6-7% improvement in lean body mass, and a 10% reduction in body fat, in a group of 78 highly trained athletes given ecdysterone.314 This was reported after only 10 days of supplementation. The second study demonstrated increased lean muscle mass, decreased body fat, and increased muscle endurance in exercising adults following 21 days of use.315 The third found ecdysterone more effective at increasing muscle endurance, and possessing a wider spectrum of anabolic action, than the steroid Dianabol.316 While these results are all extremely compelling, they were published in obscure Russian journals, usually with incomplete methodological details. This has made objective evaluation very difficult. Some of the improvements are also so remarkable as to question their validity. These studies are generally not accepted as credible evaluations of ecdysterone by Western academics.
There has been only one placebo-controlled study published in a reputable Western peer-reviewed journal that examines the effects of ecdysterone supplementation on exercising adults.317 The study involved the supplementation of ecdysterone for eight weeks (30 mg/day) in a group of men with resistance training experience. A detailed resistance training program was followed as part of the study, and measurements of strength and anaerobic performance were taken at various points throughout the experiment. Investigators could find no statistically significant or strong trends of improvement in any marker of exercise performance, anabolic/catabolic status, or body composition as a result of ecdysterone supplementation. This study does not support the use of ecdysterone to enhance exercise or athletic performance.
Ecdysterone has been widely used as a stand-alone product. The empirical evidence on this supplement has been only weakly positive. It appears that a majority of users fail to notice any significant benefit from this supplement. It is common to hear someone convey the belief that this compound is completely without merit as a sports nutrition product. At the same time, however, you can find some support for its use. A fair percentage of users do claim to notice some type of positive results from ecdysterone supplementation. Some even become loyal repeat users of these products. There is enough disparity in perceived results that two distinct camps seem to have formed over the value (or not) of this compound to athletes. Ecdysterone has an Empirical Evidence Rating of 2 (2/5).
An effective dosage of this supplement has not been established. Manufacturers commonly recommend 30-60 mg of ecdysterone per day.
Side Effects / Safety:
Ecdysterone does not appear to have toxic effects in humans.318