Neither work(Tribulus terrestris/Tribulus aquaticus) according to legitimate studies, there is however a form that shows promise, check out the study below...
Not Tribulus terrestris, but Tribulus alatus
Tribulus alatus is a plant that grows in the Sahara and Middle East. It is a relative of Tribulus terrestris, well known in the sports world in the form of supplements which manufacturers claim raise testosterone levels. Recent studies have put paid to these claims, but according to Egyptian researchers, T. alatus is a different kettle of fish.
The Egyptians did tests on male rats. The animals were given extracts of Tribulus alatus through a tube into the stomach every day for a period of forty days. Afterwards the researchers measured the amount of free testosterone in the rats’ blood.
The most interesting measurements are shaded in the table.
Concentration of free testosterone, pg per mm
2.5 milliters of water per kilo bodyweight per day
50 milligrams per kilo bodyweight per day / 70% alcoholic extract from plant minus roots and fruits
50 milligrams per kilo bodyweight per day / 70% alcoholic extract from whole plant
12.5 milligrams per kilo bodyweight per day / chloroform extract from the plant minus roots and fruits
12.5 milligrams per kilo bodyweight per day / ethyl acetate extract from the plant minus roots and fruits
12.5 milligrams per kilo bodyweight per day / butanol extract from the plant minus roots and fruits
12.5 milligrams per kilo bodyweight per day / ethanol extract from the plant minus roots and fruits
12.5 milligrams per kilo bodyweight per day / chloroform extract from fruits
12.5 milligrams per kilo bodyweight per day / ethyl acetate extract from fruits
12.5 milligrams per kilo bodyweight per day / butanol extract from fruits
12.5 milligrams per kilo bodyweight per day / ethanol extract from fruits
It looks as though T. alatus contains substances that have a pharmacological effect. It might be worth tracing these and perhaps even synthesising them. The researchers suspect that they are dealing with steroid compounds. They base . this idea on the literature. During the Communist era, Russian researchers published a lot on the anabolic effects of plant materials such as deltoside and protodioscin. On the basis of these studies, manufacturers brought Tribulus terrestris supplements on to the market, backed by claims that the plant raises testosterones levels.
Athletes who have failed drugs tests sometimes cite T. terrestris as an excuse. Because sports scientists have started to examine the extent to which athletes tell the truth, a lot of research has been published recently on the hormonal effect of T. terrestris. A Bulgarian study found that T. terrestris had no effect on the manufacture of LH, androstenedione or testosterone. Researchers in Lausanne reported similar results. The Tribulus excuse no longer holds water.
Recent studies have not been able to show any improvement in performance as a result of T. terrestris. American researchers reported already eight years ago that if weight trainers are given the supplement, they do not get stronger or gain more muscle mass. Australian researchers who tested T. terrestris on rugby players also found no positive effects on body composition or strength.
But still. Maybe T. alatus does work. According to Ergo-log’s sources, Asian companies have been buying up batches of T. alatus in recent months. Maybe it won’t be too long before we see T. alatus supplements for sale online.
By the way, T. terrestris does have a prosexual effect: it even increases sex drive in castrated rats.
Int Braz J Urol. 2007 Jul-Aug; 33(4):554-8.