HOW DO ii MAKE MY HAiiR GROW LONGER FAST?

OK RiiGHT NOW ii'M USEiiNG PANTENE BEAUTiiFUL LENGTHS SHAMPOO & CONDiiTiiONER. ii ONLY STRAiiGHTEN MY HAiiR ABOUT 4 DAYS A WEEK, iiF THAT. ii CANT USE ALOT OF CONDiiTiiONER DUE TO THE FACT THAT ii GET GREASY HAiiR iiF ii"M NOT CAREFUL...SO ii DONT KNOW iiF THERE iiS ANY THiiNG ii CAN DO TO GROW LONG HAiiR FAST WHiiLE AVOiiDiiNG GREASYNESS. ii'VE HEARD THAT PRENATAL ViiTAMiiNS MAKE YOUR HAiiR GROW, BUT ii"M NOT PREGNANT SO ii DONT KNOW iiF ii WOULD BE ABLE TO TAKE THOSE, OR iiF THEY WOULD MAKE ME FAT :]] ALL ANSWERS ARE APPRECiiATED [[thank you]]