question about Naltrexone and hpta atrophy?

Alright, a friend of mine (20 years old), started using steroids, 5-6 weeks ago, he is only on enanthate + dianabol, and readed about Naltrexone. If he start using it now (or is it late), could he stop the atrophy of the pituitary atleast? If he used it at the same day when he started the cycle, could he stopped growing and overall (as we know, there is a high chance when we use testosterone, you stop growing)? Bones are getting done, limbs e.t.c? Im retarded at english, so please if you dont understand something.. or anything tell me.