Im a 22 year old male and i was diagnosed with an underactive thyroid gland and addisons disease when i was 11, i take hydrocortizone twice daily and eltroxin 50 mg once a day. My biggest concern is the growth of my penis. It is devasting my life. The girth hasnt really come on a lot and length is below 4 inches when erect, is penis growth slowed down? What effects has it on penis growth. I need help Please, i need answers. Im at my limit here. Does it result in slower sexual growth and should i increase my eltroxin to gain more girth. Help please. Brendan.