Yes, I am referring to L-Arginine, which is good for cardio health. For your evening dose, you can instead take L-Ornithine and it will help you get a more relaxed sleep. I do find that the arginine gives me energy and sometimes would be harder to fall asleep if I had taken it recently, but the ornithine relaxes me like stated by Doc Sutter. There are lots of postings about it on the Dr. Sutter forum. Here is one of his posts about it: