TRIBULUS BENEFIT TO MANKIND

TRIBULUS terrestris is now being promoted as a booster for the purpose of increasing sex drive. Its use for this purpose originated from a Bulgarian study conducted in the 1970s, which found effects on free testosterone and lutenizing hormone in men belonging to infertile couples. A research review conducted in 2000 stated that the lack of data outside of this study prevents generalizing to healthy individuals. [7] The extract is claimed to increase the body's natural testosterone levels and thereby improve male sexual performance and help build muscle. Its muscle-building potential was popularised by American IFBB bodybuilding champion Jeffrey Petermann in the early 1970s. T. terrestris has consistently failed to increase testosterone levels in controlled studies.[8][9][10] It has also failed to demonstrate strength-enhancing properties.[11] However, many supplement brands claim effects of products that combine various herbs with T. terrestris. Tribulus has been shown to enhance sexual behaviour in an animal model.[12] It appears to do so by stimulating androgen receptors in the brain. Some body builders use T. terrestris as post cycle therapy or "PCT". After they have completed an anabolic-steroid cycle, they use it under the assumption that it will restore the body's natural testosterone levels.

Why Do People Use Tribulus?

Tribulus is most often used for infertility, erectile dysfunction, and low libido. In the last decade, it has become popular to improve sports performance. Tribulus has been marketed these conditions because research performed in Bulgaria and Russia indicates that tribulus increases levels of the hormones testosterone (by increasing luteinizing hormone), DHEA, and estrogen. The design of these research studies, however, has been questioned. A more recent study found that four weeks of tribulus supplements (at 10 to 20 milligrams per kg of body weight daily) had no effect on male sex hormones testosterone, androstenedione, or luteinizing hormone compared to people who did not take tribulus.

Erectile Dysfunction

Preliminary animal studies found that tribulus heightened sexual behavior and increased intracavernous pressure. This was attributed to increases in testosterone. There haven't been any well-designed human studies to confirm these early findings.

Body Composition and Exercise Performance

Although tribulus has become popular as a sports performance aid, one small but well-designed study found it has no effect on body composition or exercise performance. Fifteen subjects were randomly assigned to tribulus (3.21 mg per kg body weight daily) or a placebo. After eight weeks with resistance training, there were no changes in body weight, percentage fat, dietary intake, or mood in either group. What was surprising was that muscle endurance actually improved more in the placebo group. Muscle endurance (determined by the maximum number of repetitions at 100 to 200% of body weight) increased for the bench and leg presses in the placebo group. The tribulus group experienced an increase in leg press strength only.