Ecdysteroids are steroid compounds found in insects and a number of plants (phytoecdysteroids). According to an extensive review, “the metabolic fate of ecdysteroids in mammals, including humans, is only poorly known.” They appear to be non-toxic and—according to Eastern European/Soviet research, may have modest growth-promoting effects in animals. Recent research suggests ecdysterones can increase protein synthesis in human and animal muscle cells and affect muscle fiber size in rats, but more work will need to be done before they can be given an unequivocal “thumbs up” for building muscle or strength in humans.
Most commercial ecdysteroid supplements use standardized extracts from Cyanotis vaga or Rhaponticum carthamoides.
Ecdysteroids are frequently referred to as “ecdysterones,” although this is term is not widely used in the scientific literature.
Also known as dimethylxanthine. Theophylline is a metabolite of caffeine that’s also found naturally in tea. Although it’s less well-known or used in supplements, theophylline – which is used therapeutically as a bronchodilator – has effects on thermogenesis and exercise performance similar to caffeine.
A source of gamma linolenic acid (GLA) used in supplements. Borage oil has a higher percentage of GLA than evening primrose oil (23% – 24%). High quality oil should be used, however, as it may contain traces of hepatotoxic pyrrolizidine alkaloids.
A source of gamma linolenic acid (GLA) used in supplements (evening primrose oil is approx. 10% GLA). It’s used therapeutically to treat eczema. Evening primrose oil is also touted as an alternative treatment for a number of other conditions, such as arthritis, multiple sclerosis, diabetic neuropathy, PMS and menopause – but evidence of its effectiveness for these conditions is mixed and inconclusive.
An omega-6 fatty acid found in evening primrose, borage, hemp and black currant seed oil. GLA is also formed naturally in the body from linoleic acid (LA). Unlike (LA-derived) arachidonic acid (AA), however, GLA has anti-inflammatory activity. In the body, GLA is converted to dihomogamma-linolenic acid (DGLA) which competes with arachidonic acid and interferes with the formation of pro-inflammatory eicosanoids from it. In addition, DGLA-derived eicosanoids, such as PGE1, also have anti-inflammatory effects.