Cyproheptadine
ailure to thrive
"My toddler, who had been deemed "Failure to Thrive" for 2 1/2 yrs used this with success to gain weight. Negatively, I noticed he became quite more hyperactive than usual. This medicine will generally make children too sleepy, which is the main reason why they stop it, but in a normally hyperactive child it appears to do the opposite."