Not to be confused with Yohimbe; this is the synthetic derivative of the active ingredient in yohimbe.

I got it on Amazon: Serious Nutrition Yohimbine 2.5, 100 Count: Health & Personal Care

Man oh man this stuff is scary effective. To the point that I (6'2", 200lb Saber Cat) have to open and empty half of a capsule that I take at 7am in order to go to sleep by 9:30pm. A full capsule has me feeling my heart beat at the tip of my fingers with super-charged ADD brain unable to sleep (and capable of running a 5k) at 3 AM

what it does:

- think the affects of caffeine with some added rage
- increase heart rate
- literally increases core body temperature (sometimes uncomfortably - my girlfriend said I was an oven, while naked and on top of the covers at the middle of the night)
- increases blood flow to the extremities
- penis stuff

I started using it last summer and stopped after three weeks because it increased (my otherwise nonexistent) anxiety, insomnia. So I wouldn't recommend taking it on a daily basis but rather for a tactical advantage. eg on Sunday I used it before day two of my crossfit competition - finished the final two wods in Beast Mode style. I could push beyond my normal limits once I reached my threshold (or so it felt).

Highly recommended to weight lifters, athletes as an interesting boost to compare to your normal intensity base line.

A few caveats: I recommend taking half dosage (emptying a pill half way) at first and seeing how you react - especially if you are smaller than me. Secondly I recommend taking it as early in the morning as possible so as not to affect your sleep at night.