Tribulus terrstris, popularly called puncture vine, is an invasive perennial weed with a taproot and branching stems that radiate out on the ground. It produces yellow flowers about 1/2-inch wide followed by seeds that have sharp spines. The seeds resemble the horns of a bull or goat. The plant contains saponins, alkaloids and flavanoids that are the basis for assertions that is useful to enhance sexual performance and help build muscles.
Tribulis terrestris is touted as increasing the testosterone levels in males, thereby boosting sexual potency. It is marketed on the internet as a natural alternative to the performance enhancing drugs Viagra and Cialis. A Bulgarian study published in the 1970s suggested that it does, but a study released in 2005 repudiated the earlier findings. A study involving castrated rabbits and rats concluded that it does have an effect. A review of clinical studies in the American Journal of Clinical Nutrition, concluded that there are not enough data in studies involving humans to know whether or not tribulus terrestris is useful in enhancing sexual performance.
Tribulis terrestris is marketed as a dietary supplement to build muscle and enhance strength. Clinical research suggests that it does not, according to the Health Media website. A study by researchers at the University of Nebraska concluded that supplements containing tribulis terrestris had no effect on the body composition and exercise performance on resistance-trained males.
Tribulus terrestris is said to stimulate the flow of bile in the liver and increase levels of glutathione, an antioxidant. Other asserted uses of the plant as an alternative medicine include protecting the heart, killing fungi and stimulating the immune system. These purported properties are based on anecdotal evidence or deductions from reading about traditional use. There is no clinical evidence to support these claims.
Biological Land Mine
The thorns of the thorny seed of tribulis terrestris are known for puncturing bicycle tires and bare feet. In Africa there are reports that the seeds have been smeared with poison waiting to puncture the bare feet of passersby, a kind of biological land mine.