"my grandson was prescribed 1 mg guanfacine at 
age 9. he was a skinny, active kid. almost immediately, he began to gain weight. it was most noticable in his face, stomach, and rear. within 6 months, he had gained 21 pounds. i didn&#039;t notice much of a decrease in activity. even ,though weight gain was not listed as a side effect, there was no other reason for the rapid increase in his weight. no change in diet etc. when i googled weight gain and intuniv, i found many other parents complaining of the same thing. at age 10, he developed gynecomastia. that was it for me! i discontinued the medicine, and i would never consider using it again."