Hey Anna do not exceed more the 5x6cm i am recovering from my lenthening and its very hard and you are a female and female recovers slower then male only advatage you have is that if you really 21 it would be abit faster , i will tell you this for a male propotion is not as big problem as for female as you wear skir tights high heel shoes and if you lenthen the amount you saying trust me first you wont recover ever up to 100% and second sports abilty you will never get it , and think about pain killers while you lenthening your liver will be destroyed if you have to take it more then usual if any complication occurs i was a person wanted to be taller and had decent height and trust me i regret this soo much that i cannot describe it , if you just wanted to correct your legs for bow legs lets say thats fine as will recover pretty fast and prbably 100% but lenthening skin tearing big scars trust me those scars look not nice and you wouldnt want that , this is what probably will happend to you if you lenthen more then 5x6cm so you have done the surgery and lenthening pain medications stress can ever get to depression rotation problems of the bones and need to be fixed only with doctor and doctors sometimes wont see the priblems so now lenthening passed now pure consalidation phase and you cant walk for sure for at least 12 month , now i said 12month some cky boys here will say ohhh 7 month should be okay , you can listen to them as most of them dont tell the truth , so now you cannot sleep properly you feel tired all the time bored isolated from everything and only for few inches , just to look good for your self and for opposite sex , but sometimes things never works the same way as we want and i guratee you it wont work especially with the imagination amount of your planning you will regret this for your entire life , so now decigion is on your side and good luck with your life no matter what you do