Question about Etenze: Male Enhancement.?

Well, I've grown bored of the same size constantly and was thinking of ordering the product Extenze, now that I'm finally old enough. But the question I have is: Do you HAVE to have a small for it to work? What if it's already above average, will it cause it to shrink in size rather than expand? Are there any other products you guys have tried that I may be better off using?