BACKGROUND: Androgenetic alopecia (AGA) is the most common type of hair loss found in both males and females. Oral finasteride and topical minoxidil are the only drugs approved, till now, by the Food and Drug Administration of USA for the treatment of this condition. Unfortunately, these treatment options are not satisfactory. Therefore, it has been necessary to develop new agents for this psychologically frustrating disease. OBJECTIVE: This is a 16-week, double-blinded, placebo-controlled, randomized clinical trial to determine whether a new topical agent, cytopurine/pentadecanoic glyceride topical solution, is effective in showing clinical improvements in patients with AGA. METHODS: A total of 74 men and 21 women (24~55 years old) with AGA were treated either with the new topical solution or a placebo, twice daily. Efficacy was evaluated by daily shed hair count, phototrichogram and patients' subjective and investigators' subjective assessments for clinical improvement. All adverse effects were reported during the study. RESULTS: After 16 weeks of therapy, combination cytopurine/pentadecanoic glyceride topical solution treatment resulted in a significant improvement from the baseline in total hair count and daily shed hair count. But there were no statistically significant differences in anagen hair count, mean hair diameter, patients' subjective and investigators' subjective assessments for clinical improvement and side effects between the cytopurine/pentadecanoic glyceride treated and placebo group. CONCLUSION: We have confirmed the efficacy of combination cytopurine/pentadecanoic glyceride topical solution in treating AGA, by an objective assessment with phototrichogram.