I agree that that's a VERY high dose. Most women don't take more than 1,500mgs because of the cost, side effects and because taking too much won't make you grow faster than your body's willing to. It sounds like you have good genetics to respond to it so well.
I wish I could start taking maca again, but the acne it gave me was unbearable, even at the lowest doses. I may try it again once my acne is gone for good, but even then I'm sure it'll bring back my acne pretty bad. The maca personally didn't help me as much as working out did, but my testosterone is naturally high anyway, so I was able to gain about an inch a month when I was able to work out enough, and I believe I'd have gained just as much without it. Genetics really affect how you respond to maca, so those looking into it, just be warned that it may not give you the amazing effect it gives some women (it's actually pretty rare for it to work as well as it has for you).
I wish it didn't give me such bad side effects. Heck, for some people, it stabilized hormones and TOOK AWAY their acne! I wish I was one of those people. :/ With my nasty side effects, I can't take more than two a day. 1,500mgs a day made my entire body break out so bad I wanted to cry.
My friend took it with me, experienced the same side effects at the same doses and saw a lot LESS growth than me because her protein intake was so low.