5 will last you a good period of time, but once you try it, it will never be enough. Some people do it ED. I do it only on training days. Some do it after training, some before. Doses can range from say 30mcg on up. I've been using it for years and I'm definately on the high end at 100mcg. Each bottle is 1000mcg so 5 bottles gives you 5000mcg's. I would start with 5 bottles as that will allow you to see and really feel the changes. Take before and after pics. Starting out you should always start low and see where your sweet spot is. You'll love it.