the b-12 is not part of a cycle. I am using it because with having 4 kids and work, workouts, etc there seems to be more work than time. It seems to help get through this with relative calmer times, supposedly better sleep and more energy. I have taken 1ml a week lately with no problems. I have heard others say that they do 1/2 ml every other day. Just trying to get a general census or advice. I will continue with what I am doing, thanks fellas. by the way I have also heard of people thinning out some of the other daily injectables with b-12.