You want to get from a reputable company for effective results. IMO, Tribestan and Tribex are the two best pure Tribulis sups out there. Acetobolan is a good blend.

Tribulis Terretis works on your leutinizing hormone (LH) that tells your body to produce testosterone. The higher your LH - the more testosterone that your body produces.

But Anabolic and Androgenic Steroids work in a different fasion. Tribulis is closer to post sycle therapy like HCG, and Clomid which help to return natural testosterone.

I think it is most effective during the last few weeks of a training macrocycle (say... a six week program for hypertrophy) to keep off overtraining... when natural testosterone levels being to dip. And continued through a one week break before beginnning a new training cycle.

Older athletes (post 30 years of age) may find more frequent use very beneficial at raising LH.

Final word on Tribulis: You get what you pay for. Get a reputable brand for the best concentraion of the herb's beneficial properties. I frequently recommend Tribestan (Sopharma - a pioneer in Tribulis supplements), Tribex 500 (Biotest) or Acetobolan (MuscleTech).