Eighty patients with mild to moderate failure to thrive (according to Goomez criteria) and normal physical examination without any acute or chronic illness will be referred to laboratory for some paraclinical evaluations: CBC, BUN, venous blood gas, Na, K, Cr, U/A, Stool Exam, LFT, FBS, T4, TSH, TTG(IgA), Total IgA and bone scan. If all are normal, they will be enrolled in our study and their baseline weight (Wt) and height (Ht) will be recorded. Then they will be randomized to 2 equal groups to receive either combination of multivitamins and cyproheptadine (2mg of each/5cc ) or only multivitamins (2mg/5cc). The patients will consume these drugs as 0.25 mg/kg/day (divided to twice daily) for 4weeks then their Wt and Ht will be measured at the end of the treatment phase and 4 weeks later. Presumptive complications such as drowsiness or restlessness will be recorded in the clinic according to History and Physical Examination. Then results will be analyzed.