Participants were randomized to receive either the SJW extract or IAA on each split-face. The SJW extract (DR-Light complexTM; Genicos Co., Ltd, Cheongju, Korea) consisted of 70% 1, 3-butylene glycol, and 0.1% hypericin as active ingredients. After cleansing the face gently, participants applied 1.5 ml of 0.5% SJW extract on one half of the face and 1.5 ml of 0.015% IAA (AC gel®; Wellskin, Seoul, Korea) on the other half of the face for 10 minutes under occlusion.

Participants were randomized to receive either the SJW extract or IAA on each split-face. The SJW extract (DR-Light complexTM; Genicos Co., Ltd, Cheongju, Korea) consisted of 70% 1, 3-butylene glycol, and 0.1% hypericin as active ingredients. After cleansing the face gently, participants applied 1.5 ml of 0.5% SJW extract on one half of the face and 1.5 ml of 0.015% IAA (AC gel®; Wellskin, Seoul, Korea) on the other half of the face for 10 minutes under occlusion.

A 630 nm red light and a 520 nm green light of the light-emitting diode (LED) device (Nouvo-GB®) with an intensity of 35 mW⁄cm2 was simultaneously illuminated for 10 minutes (a total light dose of 21 J/cm2). Participants received a total of four treatments at 1-week intervals and were followed up 1 and 4 weeks after the last treatment.

change in the number of acne lesions after the treatment

Sebum secretion rate was measured with Sebumeter SM 815®.

The erythema index (EI) was measured with Mexameter MX 1® (Courage & Khazaka)

The skin texture and wrinkles were measured with an Antera 3D® camera (Miravex Limited, Dublin, Ireland).