So, what's the catch? As always there are those people selling bogus or diluted Tongkat Ali. As a matter of fact, the Malaysian government has banned the export of their authentic Tongkat Ali root to protect its natural habitat from being desecrated due the the popularity in the authentic root powder. It's estimated that the majority of the eurycoma longifolia currently on the market is a less potent variety from Indonesia that is even further diluted with other compounds marketed under various brand names. "I have personally tested various extracts of eurycoma longifolia in different doses and realized that it has additional side effects not often mentioned in articles or in research papers. Many of my friends and patients have given me feedback regarding their personal experiences with eurycoma supplements. I am convinced that high doses can cause increased body temperature, which is not a good thing during hot and steamy days without air conditioning, but a good thing if you live in Alaska or enjoy taking a walk outside in cool weather. Some people find that when they take a high dose, they become restless and impatient, perhaps easily angered. Therefore, you don't want to swallow several capsules of eurycoma pills if you expect to be driving in heavy traffic. So, be patient and taking lower doses".Dr. Ray Sahelian, M.D.
It should be further noted from Dr. Sahelian's Tongkat Ali product label: "Other ingredients include magnesium stearate, gelatin, & rice flour".

* also available in raw bulk Eurycoma longifolia root powder from Siam Natural herbal botanical compounds

research docs

http://en.wikipedia.org/wiki/Eurycoma_longifolia

http://www.drugs.com/npp/eurycoma-longifolia.html