Tenex is not known for decreasing growth, but there are not any good long term studies. It is a blood pressure med that works on dopamine. It can stimulate appetite or counteract the weight loss from stimulant meds for some people. My youngest eats near nothing some days and then eats everything in sight other days. My oldest used to eat like a hobbit (6 or 7 meals a day) until recently with the onset of menses, she has really reduced her intake.
Is it posible that some of the weight issues when he first moved in, he needed to adjust to his new home, food and schedule?
I have read that some of the stimulants can suppress growth in children. Is there any issue with Tenex having the same affects?