No real answer to how long it lasts from what I’ve read. Sometimes it says Long has people feel they can stay on a ADH. It can be a tough road to follow after a while. I have been on it for five years. My PSA has just started to rise, but Dr. still wants me to stay on because he said it’s still might be working a bit. I was stage four and I think doctors were surprised a bit, that first reoccurrence has taken five years also Zytiga .