We went through the same thing when my oldest was 7 years olds-  his bone age was very delayed,  I think at 4 years olds.  So his endo undersuppressed him to have him catch up-  he grew like a weed.  It seemd like overnight.  Anyway his energy was very low-  he said he could not even play at recess,  this was of course after the fact, and he would just sit and watch.  His bone age "caught up" and he was put back on a more regular dose.  I would just watch close.

He is 10 now and his bone age is just slightly behing, maybe 9-  I would say his energy level is great now.  Looking back I would probably done a slighter decrease in his meds and had it go a bit longer/

Good luck.

PS  He had been way oversuppressed when he was a baby.  Bad endo!  We switched and have been in good health since.