Tribulus terrestris is a small, herbaceous, flowering perennial native to the warmer temperate and subtropical regions of Southern Europe, South Asia, Africa and Northern Australasia. A hardy little plant, it has become extensively naturalised in the Americas, and in some states is considered to be an invasive weed.

Since the 1970's Tribulus terrestris has been gaining in popularity in the West as a dietary supplement, taken to boost production of the male sex and growth hormone, testosterone. It is thought that is was first used for this purpose in Eastern Europe, and became well known in the West after the American strong-man Jeffrey Petermann sang its praises.

Several independent studies have suggested that consumption of Tribulus terrestris can increase testosterone levels. Most studies have involved mice, rats, rabbits and primates however, and the few studies that have so far involved humans have not provided conclusive data, merely suggestive results. Whilst the jury remains out on the efficacy of Tribulus terrestris as a testosterone booster in humans, it nevertheless continues to grow in popularity and its use and availability are becoming more widespread. Its extract forms part of many herbal products, used to treat conditions as varied as hair loss and low libido. Its primary uses are as a bodybuilding supplement and male libido enhancer.

Despite only being used in the West since the ‘70's, it has a much longer pedigree in both traditional Chinese and traditional Indian medicine. The Chinese name for the herb is Bai Ji Li, and in Sanskrit it is called Gokshura. In both systems it was used as an aphrodisiac, and was widely used in the traditional Indian Ayurvedic practice.

The side-effects of taking Tribulus extract are reported to be almost non-existent. Some people may experience a mild stomach ache, but in most cases this can be eliminated by simply taking the product with, or shortly after, food. Tribulus terrestris is widely available from health food shops and online stores.