I used Tertracycline when I was a teenager and it was a miracle pill for me. I also used it in combination with Azelex (cream) and I noticed a 100% recovery from my acne. My skin was practicly flawless! However, now that Im in my twenties my acne is back with a vengence and Tetracycline no longer controls it like it used to. It was hard for me to measure success with it because Tetra only treats pustule like acne or deep cysts. I now have closed comedone acne which Tetra isn't made to effect. Also Tertraclyline is a killer if you have any acid indegestion! DO NOT take this medicine right before bed if you have any heart burn problems. I stopped taking this medicine about two months ago cause it either caused or help attribute to terrible heart burn. This is a great medicine however if you are careful to use it properly AND consistantly for three months straight. Patience my dears, patience.