It is believed to enhance testosterone levels by encouraging the production of lutenizing hormone. Studies have shown that when lutenizing hormone levels are increased, the natural production of testosterone also increases.
It is difficult to assess the validity of tribulus as a muscle growth enhancer because none of the studies carried out have appeared in peer-reviewed scientific journals. Its proponents do suggest that it can prove useful when stacked with 100 mg of DHEA and 100 mg of androstenedione but this takes us into the equally uncertain territory of prohormones which we have covered in a separate article.
If you do wish to experiment with tribulus you can take 750-1250 mg per day divided between meals. Some people experience stomach upsets but this can be minimized by taking it with food. There's no guarantee that tribulus terrestris will help you grow bigger muscles but many users report a much improved sex drive!