OBJECTIVES: Malnutrition is prevalent among children with cystic fibrosis (CF), often resulting from frequent pulmonary exacerbations and intestinal malabsorption. In addition to providing sufficient calorie intake through enteral formulas, appetite stimulants may help address nutritional deficiencies and improve overall prognosis. METHODS: This retrospective study included children who received cyproheptadine (CH) as an appetite stimulant for at least three consecutive months. Data on CH-related adverse effects, z-scores for weight, height, body mass index (BMI), and percentage of forced expiratory volume in 1 s (FEV RESULTS: The study included 45 children with a mean age of 11 years. One patient was on modulator therapy, one was pancreatic sufficient, and another one had diabetes. Only one patient was using enteral supplementation simultaneously with CH. Significant improvements in weight and BMI z-scores were observed from baseline to three months of CH therapy (p = 0.004 and p = 0.006, respectively), with no significant changes noted in the three months before treatment. A modest increase in weight and BMI z-scores was seen from three to six months of therapy. Additionally, FEV CONCLUSION: Six months of CH therapy was associated with significant improvements in weight and BMI z-scores, particularly within the first three months. No adverse effects were reported. Given the deceleration in the rate of increase in anthropometric z-scores from the third to sixth month, a three-month duration of CH therapy appears to be optimal and sufficient for children with CF.