Inhibitory effects of Cheongsangbangpoong-tang on both inflammatory acne lesion and facial heat in patients with acne vulgaris: A double-blinded randomized controlled trial.

•Cheongsangbangpoong-tang (CBT) is one of the herbal formulas for clinical use in patients with acne vulgaris.•CBT significantly relieved not non-inflammatory lesion counts but inflammatory lesion counts of patients with acne vulgaris.•The facial heat at baseline in some acne pattern recovered significantly to normal state after CBT administration.•There were no severe adverse events in taking 5g CBT three times a day for 8 weeks.