Cyproheptadine is currently clinically used as an appetite stimulant for children with
failure to thrive without underlying organic disease. Otherwise, no randomised control trial
demonstrates the efficacy of Cyproheptadine on those patients. This is precisely what the
investigators intend to demonstrate on this randomised placebo control cross-over trial. Our
hypothesis is that Cyproheptadine is more efficient than placebo to improve weight gain and
feeding behaviour on 2 to 4 years old children with failure to thrive.