Viagra works for 2/3 of the men who try it. You might just be in the 1/3 group for which it is not a solution.
All ED drugs are PDE5 inhibitors. The path from arousal to hardness goes something like this:
Stimulation > Nitric Oxide or NO > cGMP > PDE5 > partial recycling
Here is a more detailed graphic:
http://science.howstuffworks.com/viagra5.htmI won't bore you with a long chemistry lesson. What's important is to notice how late in the chemical chain the PDE5 is happening! The problem is that PDE5 inhibition
only extends the life of the cGMP. If your body does not create enough Nitric Oxide or cGMP in the first place then the Viagra won't help that much.
Feeding the NO engine is the other 1/2 of the puzzle.NO = arginine + oxygen + NADPH (an enzyme)
Arginine you can supplement.
Oxygen = movement/exercise
Niacin is the N in NADPH... again, we can supplement this.
Hope that helps!