I use Saliva Test Strips to measure my Nitric Oxide. I went from ZERO to 100% by taking supplements and changing my diet.
The results have been Miraculous. Teenage erections all week, more energy,MUCH improved sleep with vivid dreams that I have not experienced in decades.
The doctors who won the Nobel Award for their work on Nitric Oxide suggest taking L-Argenine & L-Citruline. Amazon.com carries several different brands.
I have no side effects. This is the closest we will come to the "Fountain of Youth." Raising Nitric Oxide also prevents further damage to the arteries, required for the brain and every organ in our body.
Now with my major success at curing Erectile Dysfunction, I'm reducing the supplement dosages to focus more on the foods that raise Nitric Oxide.