Open-label, single-centre, split-face randomised, parallel-group controlled trial to evaluate the efficacy and skin compatibility of a cosmetic set containing alpha-arbutin and retinol on post-procedure barrier restoration, hydration, soothing, and comprehensive photoaging improvement following a single combined 20% glycolic acid chemical peeling and broadband light (BBL) treatment, and under normal daily use in healthy Asian females
Skin aging
Cohort 1 (aesthetic treatment cohort): Prior to the aesthetic procedure, all participants will thoroughly cleanse the full facial treatment area. A 0.4–0.5 ml dose of 20% glycolic acid will be spread evenly across the entire face and left in place for 3 to 5 minutes. Following neutralisation, disposable facial wipes dampened with sterile normal saline will gently remove all residual acid from the face. Photoconductive gel will be applied uniformly over the face immediately before broadband light (BBL) therapy. Two filters (695 nm and 590 nm) will be used for each participant, with individualised treatment parameters set based on clinical assessment. For the first 3 days after treatment, participants will apply one hyaluronic acid repair sheet mask to the full face once daily. Starting on Day 3, a randomised split-face routine will be maintained for 25 consecutive days: one hemiface will receive alpha-arbutin toner each morning and alpha-arbutin toner plus retinol lotion each evening; the contralateral hemiface will receive placebo toner each morning and placebo toner plus lotion each evening. Participants attended four study visits: at baseline (D0), immediately after the aesthetic treatment before product application (D0′), and 7 days (D7) and 28 days (D28) after product application. Cohort 2 (daily routine use cohort): No aesthetic intervention will be administered. Participants will apply alpha-arbutin toner to the full face each morning and alpha-arbutin toner combined with retinol lotion each evening for 28 consecutive days. Participants attended three study visits: at baseline (D0) and 7 days (D7) and 28 days (D28) after product application. Randomisation method (within-subject, split-face): Within Cohort 1 (aesthetic treatment cohort), a within-subject, split-face randomised design will be used. The hemiface allocation sequence will be generated automatically using random codes in Microsoft Excel. One hemiface receives the test product (alpha-arbutin toner
1. Healthy Asian female participants aged 18 to 60 years 2. Fitzpatrick skin phototypes III to IV 3. Presentation of mild to moderate facial skin concerns, including dullness, sallow complexion, erythema, rough texture, sagging, dry lines, fine lines, crow’s feet wrinkles and enlarged pores 4. Maintain a regular skincare routine and consistent use of sunscreen products 5. Have not received intense pulsed light (IPL) therapy or chemical peeling within 6 months prior to study commencement, and have not undergone any other aesthetic medical treatments within 1 year prior to study commencement 6. Have not applied topical retinoid preparations to the face within 6 months prior to study commencement, have no history of oral retinoid use, and have not used exfoliating products within 1 week prior to study commencement 7. Able to understand the trial procedures, take part voluntarily and provide written informed consent
1. Pregnancy or breastfeeding 2. Presentation of cutaneous disorders at the test site, such as psoriasis, allergic dermatitis and seborrhoeic dermatitis 3. Suffering from severe, unstable or progressive illnesses as judged by the investigator, including diabetes, hypertension, hypothyroidism or hyperthyroidism, which may alter the facial skin parameters under assessment 4. Expectation of receiving any treatments capable of interfering with trial outcomes throughout the study period, including systemic or topical anti‑inflammatory agents, antihistamines, antibiotics and desensitisation therapy 5. Documented history of adverse cutaneous reactions to products belonging to the same category as the test cosmetic set. 6. Participation in, or current enrolment in, any other facial clinical testing within the preceding 1 month