The goal of this clinical trial is to compare the dermatological tolerance and skin-lightening efficacy of a cosmetic depigmenting serum to a 4% hydroquinone-based product in adult male and female subjects aged 18-65 years with mild to moderate epidermal or mixed-type melasma.

The main questions it aims to answer are:

Does the cosmetic serum reduce the severity of melasma (measured by mMASI) after 84 days of use?

Is the cosmetic serum better tolerated than 4% hydroquinone under real-use conditions?

Researchers will compare the serum group and the hydroquinone group to determine whether the cosmetic product achieves comparable pigmentation improvement with superior skin tolerability.

Participants will:

Group 1: Apply a morning routine (Depiwhite Serum + Depiwhite M SPF50+ cream) Apply an evening routine (Depiwhite Serum + Placebo Cream without Hydroquinone)

Group 2: Apply a morning routine (Serum Placebo + Depiwhite M SPF50+ cream) Apply an evening routine (Serum Placebo + Depigmenting Cream with hydroquinone 4%)

Visit the clinical site at baseline (Day 0), Day 56, and Day 84 for assessments

Complete standardized photographs, self-assessment questionnaires, and quality-of-life surveys (MELASQoL and ASLQI)

Undergo clinical evaluations by a dermatologist, including mMASI scoring and tolerance assessment

Melasma is a chronic hyperpigmentation disorder of multifactorial origin, often aggravated by ultraviolet (UV) radiation, hormonal changes, and inflammation. It predominantly affects individuals with Fitzpatrick skin phototypes III to V and manifests as irregular brown macules and patches, particularly on sun-exposed facial areas. While 4% hydroquinone remains the gold standard topical agent for melasma, its long-term use is associated with adverse events such as irritant dermatitis and exogenous ochronosis, prompting the development of alternative dermocosmetic formulations.

This double-blind, randomized, controlled trial investigates the comparative efficacy and cutaneous tolerance of an intensive anti-spot cosmetic serum (Depiwhite Serum) versus a hydroquinone 4% cream (Eldopinone), both used in conjunction with a high-protection SPF50+ sunscreen (Depiwhite.M). The serum incorporates a combination of active ingredients designed to target melanogenesis and its upstream mediators through a multi-pathway mechanism, including anti-inflammatory, antioxidant, and melanin-regulatory actions.

The study will evaluate changes in melasma severity using a modified Melasma Area and Severity Index (mMASI) score and standardized facial photography acquired with the ColorFace® imaging system. These photographs will undergo high-resolution colorimetric analysis by QIMA Life Sciences, quantifying pigmentation changes through CIELab parameters (L*, a*, b*), ITA°, and contrast metrics (ΔE76, ΔITA°, etc.), tracked across predefined regions of interest (ROIs) from lesional and perilesional skin.

Additional assessments include subjective product performance evaluation, cosmetic acceptability, and patient-reported outcomes using two validated quality-of-life instruments (MELASQoL and ASLQI). Safety and local tolerance will be monitored at each clinical visit via dermatologist-led skin examinations and subject-reported functional symptoms.

The trial aims to generate robust clinical and instrumental data supporting the use of cosmetic formulations as a potential alternative or maintenance therapy to hydroquinone in melasma management, particularly for populations seeking better tolerability profiles without compromising efficacy.

Amendment Note (15 August 2025 The inclusion criteria have been revised to allow subjects with a baseline mMASI score of ≥3.5 (previously ≥4) to accommodate borderline moderate melasma cases. This change is reflected in Protocol Version 2.0.

Inclusion Criteria:

Male or female subjects, primarily female, aged 18 to 65 years at the time of inclusion

Fitzpatrick skin phototype II to V

Diagnosed with mild to moderate epidermal or mixed-type facial melasma, confirmed by Wood's lamp examination

mMASI score between 3.5 and 13 at baseline

Subject is in general good health as assessed by the investigator based on medical history and clinical examination

Willing to avoid excessive sun exposure and use only the provided SPF50+ sunscreen during the study

Able to understand the study procedures and provide written informed consent

Willing and able to comply with study procedures and scheduled visits

Women of childbearing potential must agree to use a reliable method of contraception for at least 3 months prior to and during the entire study duration

Exclusion Criteria:

Presence of post-inflammatory hyperpigmentation (PIH), lentigines, or other non-melasma facial pigmentation

Use of topical or systemic depigmenting treatments, retinoids, corticosteroids, or hormonal treatments within 4 weeks prior to baseline

Known allergy or hypersensitivity to any component of the investigational or comparator products

Excessive sun exposure or use of tanning beds within 2 weeks before baseline or planned during the study

Active skin diseases (e.g., atopic dermatitis, psoriasis) or damaged skin in the test area

Pregnant or breastfeeding women, or those planning to become pregnant during the study

Participation in another clinical trial within 4 weeks prior to the study or planned participation in another trial during the study

History of malignancy in the past 10 years (except treated basal cell carcinoma)

Uncontrolled systemic illness (e.g., diabetes, cardiovascular, hepatic, renal, or pulmonary disease)

Any psychological or cognitive condition that would limit the subject's ability to understand the study procedures

Current use of photosensitizing medications

BMI > 40 or other conditions that may affect protocol compliance as judged by the investigator

Individual Participant Data (IPD) will not be shared for this study. The trial involves cosmetic products and is not subject to regulatory requirements mandating data sharing. Additionally, participant privacy and confidentiality are prioritized, and the data collected are not intended for secondary research use.

Investigator is: The principal investigator who was masked