According to this, it does not, but isnt that too good to be true?
One of the biggest reasons that so many guys are using tongkat ali extract is because of its ability toincrease your testosterone levels. Tongkat ali will indeed give you a large boost in testosterone, but thankfully not in the way that most testosterone boosters do.
While most synthetic testosterone boosters increase the amount of testosterone being produced by your Leydig cells (which in turn causes them to eventually stop producing testosterone), tongkat ali actually boosts your amount of Leydig cells you have while also helping your body use it’s natural amount of hormones more effectively. The result, no rebound effect and epic testosterone levels
Along with increasing Leydig production, what tongkat ali extract does is release this bind and lower your levels of SHGB so that your body can use more of it’s natural free testosterone. This wards off the fear of your body producing less sex hormones over time, like it does with most testosterone boosters. This is one of the main reasons why the longer you use tongkat ali extract, the bigger the boost in free testosterone you will have.
http://www.menprovem...at-ali-extract/
This study also says its a maintainer. so it shouldnt cause tolerance
In this way, eurycoma may be considered not so much a testosterone “booster” (such as an anabolic steroid), but rather a “maintainer” of normal testosterone levels and a “restorer” of normal testosterone levels (from “low” back “up” to normal ranges) [19]. This would make eurycoma particularly beneficial for individuals with sub-normal testosterone levels, including those who are dieting for weight loss,
http://www.ncbi.nlm....les/PMC3669033/
Also there was a study on it for hypogonadic men, i doubt they would take it if right after stopping use they would have decreased levels/rebound?
Here is the study: http://www.ncbi.nlm....pubmed/21671978
Edited by sonshoku, 07 October 2015 - 02:50 PM.