What it says on the label:
 
iSatori H+ Blocker
When Combined with a structured diet and intense weight-training regimen, H+Blocker components have been shown to:

• bind hydrogen ions/stabilize pH Levels in Muscle Plasma
  
• Improve Peak Musclular Contractions
  
• Generate Increased Blood Flow
  
• Extend Musclular Endurance
  
• Maximize Total Power Output
  
• Enhance Recovery Time

FOR BEST RESULTS, use continuously for a minimum of eight weeks.  (said elsewhere that the longer you take it the more effective it is)
 
 
What it has done for me so far:
 
Made me come up with a good combination of other things(juice, amino acid mix(tastes really good)) to make it taste halfway decent. If you require your supps to taste gooood...dont take this.
 
Slightly bigger pumps, allowed me to finally see my outer bicep   :D
 
But the MAIN difference i have noticed already is that i can do the same amount of reps to failure for the same weight for the same excercise, no matter what. Beginning or end of workout or superset, or before or after doing other excercises for the same muscle.
 
So far, apart from taste, I have been happy with results, but I hope iSatori wasnt lying when they say that it works better after taking it for awhile.