It's supposed to be better. How many people have had good results with 2% minoxidil? Not many. How many people have had good results with 5% minoxidil? Quite a few. It seems like the higher the percentage of minoxidil the better the growth. So 15% would probably blow away 5% minoxidil. Besides Xandrox 15% also has azelaic acid in it(5%) and that is supposed to keep DHT from being formed at the follicular level. I'm not sure how much research has been on the azelaic acid, but that doesn't mean it won't work. Azelaic acid from what I remember was also used to treat acne. I think some people still use it too. You should ask Dr. Lee about this.