depending how old the teen is, hgh can cause him to grow taller most definetly. as far as muscle growth, an androgen will work favorably with his natural growth hormone levels, but if he is a young teen it is detrimental. without knowing his age i can say hgh wont hurt him, but androgens will. males continue to grow in height past there teens, so an androgen will hurt bone growth. though he can safely take anavar and this will not hurt bone growth but will aid muscle growth somewhat, but not much. though anavar can supress him naturally. its really a balancing act. teens should pretty much stay away from growth drugs and focus on nutrients and heavy training.
-lc