||Abstract Objectives: The objectives of this study were to evaluate the efficacy and interaction of Keigai-rengyo-to extract (KRTE) and acupuncture in male patients with acne and the feasibility of a large clinical trial. Design: A randomized, assessor single-blinded, 2x2 factorial trial was conducted. The trial is registered with the Clinical Research Information Service, Republic of Korea: KCT0000071. Subjects: Forty-four (44) participants with acne vulgaris were randomized into one of four groups: waiting list group (WL), KRTE only group (KO), acupuncture only group (AO), and KRTE and acupuncture combined treatment group (KA). Intervention: After randomization, patients in the AO and KA groups underwent eight sessions of acupuncture treatment, twice per week. Patients in the KO and KA groups were prescribed KRTE 3 times daily, 7.4 g each dose, after meals, for 4 weeks. Outcome measures: The following outcome measurements were used in examination of subjects: mean percentage change and the count change of inflammatory and noninflammatory acne lesions, Skindex 29, investigator global assessment from baseline to end of trial, and proportion of dropouts and compliance with KRTE. Results: A significant interaction of KRTE and acupuncture was evident according to mean percent change of inflammatory acne lesions, but not of noninflammatory acne lesions from baseline to the end of the study. Statistically significant differences were observed in the primary effect on mean percent change of noninflammatory acne lesions, not by acupuncture, but by KRTE. Adjusted Skindex 29 score changes indicated no statistically significant reduction within groups and between groups. The improvement rate in patients with KRTE and acupuncture treatment was not significant, compared to patients with no KRTE and acupuncture treatment. The proportion of dropouts was 22.7% and rate of compliance with KRTE was 92.3%. Conclusions: For treatment of acne vulgaris, use of KRTE combined with acupuncture is recommended for inflammatory lesions and KRTE only is recommended for noninflammatory lesions. Further large-scale trials assuming a higher dropout rate and aimed at confirming the ability of KRTE and acupuncture to improve inflammatory and noninflammatory lesions in patients with acne are needed.