Susan, Be thankful that your son is lean. Because of the high dose of cortef they gave my youngest daughter at birth, she gained so much weight at only 6 months of age I could not even carry her. The doctors said it had nothing to do with the meds. But later I found out that was far from the truth. My oldest also put on a lot of weight at 3 years of age when they said she had advanced bone growth and they really increased her meds and she started gaining 15 pounds a month. They are still very large, but I sent my oldest to weightwatchers and she lost 30 pounds. My youngest is still having problems. Five months ago I told my Endo, to take her off of florinef and we did. She has had no problems. The only weight she has lost is on the back of her neck down by the spine. ( So be happy that the doctor is not over medicating him). If he is having lots of stomach problems, health problems and not growing right, then I would question the dose of meds. Otherwise I would just stay where you are on the meds. The doctors said it had to do with what I was feeding my daughters which was keeping them heavy. But I am 5'4" and weigh 115 pounds and my husband is far from being over weight. My daughters are the heaviest in my family on both sides. Just be careful that they never over medicate him because if they do what's going to happen to him is that his body will adjust to that dose and it will be harder for you to lower the dose and then he will start to gain and then they will raise it again until it becomes harder to lower it. Good luck, Norma