Tribulus Terrestris

Tribulus Terrestris is a flowering plant in the family Zygophyllaceae, native to warm temperate and tropical regions of southern Europe, southern Asia, throughout Africa, and in northern Australia.
Tribulus Terrestris has many common names. Puncture Vine, Caltrop, Yellow Vine, and Goathead are the most widely used; others include

• Bindy Eye
• Bindii
• Bullhead
• Burnut
• Burra Gokhroo
• Calthrops
• Cat's Head
• Common Dubbeltjie
• Devil's Thorn
• Devil's Weed
• Doublegee
• Dubbeltje
• Gokshura
• Ground Bur-nut
• IsiHoho
• Land Caltrop
• Maltese Cross
• Mexican Sandbur
• Puncture Weed
• Rose
• Small Caltrops
• Jackweed
• Texas sandbur
  

The Latin name Tribulus originally meant the caltrop (a spiky weapon), but in Classical times already meant this plant as well.
Tribulus terrestris has long been used as a tonic and aphrodisiac in Indian ayurveda practice.

It is now being promoted as a testosterone booster for the purpose of building muscle and increasing sex drive. Independent studies have suggested that Tribulus Terrestris extract does increase testosterone levels.
Some have compared the tonic properties of Tribulus Terrestris to the effects of ginseng, but these occur due to entirely different mechanisms. Claims have been made that it enhances testosterone levels by increasing luteinizing hormone (LH) levels. LH is responsible for "telling" the body to produce testosterone. One interesting fact is that extended use of anabolic steroids reduces levels of LH, thus reducing and sometimes shutting down the body's production of testosterone.
It is also claimed that Tribulus Terrestris increases testosterone by increasing gonadotropin-releasing hormone (GnRH) which in turn stimulates the production of LH and follicle-stimulating hormone (FSH). Testosterone, besides its role in muscle-building and raising fertility and libido, is also known to have a positive effect on bone marrow activity (for red blood cell production) and the immune system.[citation needed]
Tribulus Terrestris may be beneficial for those whose testosterone is below normal, such as dieters and overtrained athletes.

No significant adverse effects have been reported from supplementation with Tribulus Terrestris. However, some users report an upset stomach, which can usually be counteracted by taking it with food.