I have passed through the danger zone multiple times. By that I mean I am clean over a year. Over a year, no relapses, no porn, no PMO, no MO. I am not hard mode, I do have a wonderful woman in my life. The question about supplements is really just your brain asking "is there an easy way out?" I am sorry to tell you, there is only one way out, a very difficult--but doable--way, and that is to totally eliminate the stimulation of porn from your life experience. That will lead to withdrawals if you are addicted. I don't know if you are, but if you are here because you don't like how your porn consumption has effected your life--you probably are. I am. I was. There is only one way to deal with withdrawals, and that is embrace them. The are going to hurt, terribly, they are mental, physical, and emotional pain. They are the opposite of pleasure. Why do they happen? They are your brain's reward center (which rewards with dopamine, which like any great drug feels great or pleasurable) coming back down to normal levels. Horny goat weed is just a myth, that and someone trying to sell you something.
I hope this helps.
Peace.