The goal of this clinical trial is to etermine and compare the effectiveness of three therapeutic regimens for mild to moderate acne vulgaris, such as, clindamycin-retinoid combination, clindamycin-retinoid-dexamethasone combination, and sekretome SM-hUCMSC 10% gel. The main questions it aims to answer are :

• Is there a change in the number of inflammatory lesions (papules, pustules, nodules) and non-inflammatory lesions (open and closed comedones) before and after treatment in each treatment group?
• Is there a difference in the reduction of acne vulgaris severity scores among the three treatment groups?
• Are there differences in the rate of clinical improvement (time required to achieve a certain reduction in lesion count or severity score) among the treatment groups?
• What are the incidence and characteristics of local adverse effects (erythema, burning sensation, skin dryness, irritation, hypo-/hyperpigmentation, and others) in each treatment group?
• Are there differences in the impact of each therapeutic regimen on the risk of acne scar formation and improvement in skin quality (texture, elasticity, and color homogeneity)?
• Does secretome gel demonstrate sufficient clinical potential and urgency as a safer and more prospective topical therapeutic alternative for acne vulgaris compared with retinol-clindamycin and retinol-clindamycin-dexamethasone 0.1% combinations?

Participants will be allocated into three groups using simple block randomization.

• Group A will receive a combination of clindamycin and a retinoid, applied thinly to the entire facial area once daily at night.
• Group B will receive a combination of clindamycin, a retinoid, and dexamethasone, with the same method of application as Group A.
• Group C will receive 10% SM-hUCMSC secretome gel, applied thinly to acne-affected areas twice daily (morning and night).

This study aims to determine and compare the effectiveness of three therapeutic regimens for mild to moderate acne vulgaris: (1) a combination of clindamycin-retinoid, (2) a combination of clindamycin-retinoid-dexamethasone, and (3) 10% SM-hUCMSC secretome gel.

This study employed a quasi-experimental pre-post design with three intervention arms and was conducted at the Precious Me Clinic, Serpong. Subjects were divided into three groups:

Group A received Mediklin TR (clindamycin-retinoid), applied once daily at night.

Group B received Solanum Night Cream (clindamycin-retinoid-dexamethasone), applied once daily at night.

Group C received 10% SM-hUCMSC secretome gel. The secretome was derived from human umbilical cord mesenchymal stem cells (SM-hUCMSC) cultured up to passage 6 in MEM-α medium without growth supplements, incubated under hypoxic conditions (5% O₂) for 72 hours, and the conditioned medium was stored at -80°C before being formulated into a 10% gel. The gel was applied thinly to acne-affected areas twice daily (morning and night) for 8 weeks. Evaluations were performed at weeks 0, 2, 4, and 8.

Throughout the trial period, participants were instructed to continue using sunscreen and were allowed to use the same mild facial cleanser and non-comedogenic moisturizer (standardized by the investigators) to minimize bias.

The study utilized an AI-assisted face/skin analyzer (e.g., Langdi Skin Analyzer), acne lesion count forms, the Cardiff Acne Disability Index (CADI) questionnaire, adverse event recording sheets, and a standard digital camera as research instruments.

Inclusion Criteria:

• Age 15-40 years.
• Clinical diagnosis of mild to moderate acne vulgaris on the facial area.
• Primary lesion location on the face, with a total lesion count meeting the above criteria.
• Not currently using topical or systemic acne therapy within: the past 2 weeks for topical therapy; the past 4 weeks for systemic therapy (oral antibiotics, isotretinoin, or systemic steroids).
• Willing to use only the treatment regimen provided by the investigators on the facial area throughout the study period.
• Willing to adhere to the scheduled follow-up visits (weeks 0, 2, 4, and 8) and to sign informed consent.

Exclusion Criteria:

• Presence of other facial skin diseases that may interfere with acne assessment (e.g., rosacea, contact dermatitis, impetigo, fungal infections, herpes, etc.).
• History of hypersensitivity or allergy to clindamycin, retinoids, topical corticosteroids, or any components of the secretome gel.
• Use of oral isotretinoin within the past 6 months.
• Pregnancy or breastfeeding.
• History of severe immunological disorders or uncontrolled systemic diseases (e.g., uncontrolled diabetes mellitus, severe liver or kidney disease).
• Presence of extensive open wounds or active infections on the face.
• Undergoing aggressive facial cosmetic procedures within the past 3 months (e.g., ablative laser, deep chemical peeling, dermabrasion).