Background: Ceramide is important in barrier function of epidermis. It can reduce epidermal water loss and inhibit producing dandruff. Ceramide is an essential component in protecting hair and can be used as a cosmetic ingredient to improve seborrheic dermatitis and subjective symptoms like pruritus. Objectives: We aimed to evaluate the efficacy of synthetic ceramide on dandruff, erythema, sebum secretion and water loss. Methods: Total of 20 subjects, 10 were randomly assigned to ceramide group and other 10 were assigned to controlled group. The subjects had received the evaluation of scalp before the trial and after using shampoo 15ml once a day for 4 weeks. Scores were assessed about dandruff and scalp erythema. Sebum was collected using sebumeter and sebum secretion was recorded at 4 parts (frontal, vertex, both temporal area). Water content of scalp was measured using corneometer at same sites. Results: After 4 weeks, 8 patients had favorable outcomes with ceramide shampoo in dandruff compared with 4 patients in control. And 4 patients had favorable outcomes with ceramide shampoo in erythema compared with 3 patients in control. Sebum secretion increased in ceramide group and decreased in control, but not statistically significant. Water content showed a tendency to increase in ceramide group, whereas water content significantly decreased in control. Conclusion: These results indicate that synthetic ceramide is effective in improving dandruff, erythema and reducing water loss.