In glycyrrhetinic acid, the functional group ( R ) is a hydroxyl group. Research in 2005 demonstrated that with a proper functional group a very effective glycyrrhetinic artificial sweetener can be obtained.  When R is an anionic NHCO(CH 2 )CO 2 K side chain , the sweetening effect is found to 1200 times that of sugar (human sensory panel data). A shorter or longer spacer reduces the sweetening effect. One explanation is that the taste bud cell receptor has nanometers (13 angstroms ) available for docking with the sweetener molecule. In addition the sweetener molecule requires three proton donor positions of which two reside at the extremities to be able to interact efficiently with the receptor cavity.
Extracts from T. terrestris standardised for protodioscin content have been demonstrated to produce proerectile effects in isolated tissues and aphrodisiac action in several animal species.   It is thought protodioscin achieves this primarily through causing an increase in androgen receptor immunoreacivity, meaning it increases the concentration of androgen receptors in cells, causing the organism to become more sensitive to androgens like testosterone and DHT.  The mechanism for these effects has not been clearly established, and while protodioscin has been demonstrated to trigger release of nitric oxide in corpus cavernosum tissue,  and also to produce statistically significant increases in the levels of the hormones testosterone , dihydrotestosterone and dehydroepiandrosterone in animal studies,  studies in humans have failed to show efficacy and its use remains controversial.  
In addition, tribulus has been shown to have a positive effect on the number of testosterone receptors in the cells. This means that the body not only produces more testosterone, but becomes more sensitive to its effects. Testosterone, of course, is the holy grail of bodybuilding, because it is widely known to enhance the body's ability to build muscle and strength. Tribulus is not a hormone, instead, it works by maximising the body's own natural hormone production. So it is a safe and legal way to optimise performance and muscle gains. On top of this, recent research has shown that using Tribulus may lower blood sugar and reduce cholesterol.