Tribulus terrestris is a herb from Ayurveda that is mostly recommended for male health including virility and vitality, and specifically more catered towards cardiovascular and urogenital health. It is a common supplement for its libido enhancing properties and supposed testosterone boosting properties.
On the sexual side of things, tribulus does appear to be a relatively reliable and potent libido enhancer in rats and the lone human study assessing this has confirmed an increase in sexual well being and erectile function. While it is not exactly known how tribulus works, it is known to enhance androgen receptor density in the brain (muscle tissue not confirmed) which may enhance the libido enhancing properties of androgens. Limited evidence suggests that it is weak to non-effective in enhancing fertility.
A specific component, tribulosin, appears to be quite potently cardioprotective and is effective in the 1-10nM range. It has not yet been tested in living creatures, but remains a very promising option.
In animal research, the fruits of tribulus appears to protect the organs (mostly liver and kidneys) from oxidative damages at reasonably low dosages and also exert anti-stress effects; confirming the status of tribulusterrestris as an adaptogen.
The herb seems to be a possibly healthy herb that enhances sexuality but with limited use for power output and testosterone.
Given a 60% saponin extract, a dose of between 200-450mg a day is typically used for libido enhancement and sexuality. If rodent research applies to humans, then the dosage of 5mg/kg of tribulusterrestris saponins which is seen as the optimal dose would correlate to a human dose of:
• 55 mg saponins (90 mg of a 60% extract)
• 70 mg saponins (120 mg of a 60% extract)
• 90 mg saponins (150 mg of a 60% extract)
Which suggests low doses are better. If a concentrated extract is not used, traditional dosages of the basic root powder are in the 5-6g range while the fruits are in the 2-3g range.