I can second VS's findings... Tongkat Ali has also helped me tremendously, not in capsule form but in coffee. A few points:
1) The coffee I tried comes in a sachet, Alicafe PowerRoot 5-in-1 including Tongkat Ali and Ginseng.
I studied its effect on me over the period of 1 month, by the 2nd week it was as if I was a different person. The general symptoms such as brain fog, concentration problems and social phobia started to melt away. Before the tongkat ali I was a pale, tired, low-energy type person who would literally feel on death's painful doorstep after O. While on the coffee, I could manage 1-2 O per week without most of the debilitating symptoms.
Why did I stop after 1 month... A major reason was gastritis, I have a lot of digestive issues which I am still trying to sort out. One of my doctor's recommendations was to stop drinking coffee. A second reason was I had trouble accepting this new "personality", I guess I spent so long with a black cloud floating over my head that the change was a bit of a shock to me.. and also to others. A third reason is availability, this coffee is not readily available where I am.
2) Why not Tongkat Ali capsules?
Well I did try, I bought Vitroman brand Tongkat Ali 100 for an exorbitant sum to try it out instead of the coffee. I took them daily for a couple of weeks, they did not seem to benefit me, rather worsening my gastritis. I also tried to empty the capsules into some milo and drink it that way (really bitter!), but that didn't seem to help either. I suspect there is a lot of difference between different manufacturers... they have a system for specifying tongkat exctract concentration (100:1, 200:1, etc). I did watch a documentary on youtube about tonkgat ali, and it's traditionally brewed by boiling the root for an extended period followed by drinking as a hot drink.
3) Other info
I have ingested plenty of regular coffee and also ginseng coffee in the past, without the same effect.
Conclusion
If you don't have severe heartburn and bloating like me, then the Tongkat Ali coffee may help you a lot. Personally, I think I have come to terms with the personality changes that came with the coffee and once my gastric issues have improved I will try drinking it regularly again.