This study aims at assessing the non-inferiority of tested formula facial serum (2039125 03) versus hydroquinone 4% over 3 months for treatment and then 3 months for maintenance ofwomen subjects presenting facial melasma.

Topical treatments are usually used first line. Among a high number of molecules claiming a depigmenting effect, hydroquinone used at various concentrations (typically 2 to 5%) is the most widely used skin depigmenting product and is considered, up to now, the gold standard when used at 4-5%.

Hydroquinone is sometimes combined in the Kligman's trio, with topical tretinoin and topical steroids, which remains the best initial treatment for melasma in terms of efficacy.

This randomized , two-arm study is carried out with a new cosmetic formulation developed with the aim of acting on facial hyperpigmentation.

This clinical trial is conducted in accordance with the protocol, the HELSINKI declaration (1964) and subsequent amendments, and/or the International Council on Harmonization (ICH) Good Clinical Practices (GCP)/ and in compliance with applicable regulatory requirements.

Statistical Analysis:

• Primary Efficacy Analysis: The primary performance endpoint is the difference between tested formula facial serum (2039125 03) versus hydroquinone 4% in mean change from baseline in modified Melasma Area Severity Index (mMASI) score at D84. A non-inferiority followed by a superiority evaluation will be assessed.
• Sensitivity analyses The same analysis will be repeated on the FAS population. Missing values (i.e. data of patients who dropped out the study or with no evaluable data) will not be imputed for this analysis.

Depending on the results of the baseline characteristics description, other sensitivity analyses could be performed by adding other relevant baseline covariables to the model.

. Safety Analysis: no statistical analysis will be performed on safety. The data are presented descriptively.

Categorical data are summarized using the number and percentage of patients in each category. Continuous data are summarized using the arithmetic mean, Standard Deviation (SD), Q1, Q3, minimum, median and maximum values.

Regarding the sample size determination, there was no formal calculation. A number of 104 patients , 52 patients in each group was considered sufficient to meet the study objective.

Inclusion Criteria:

1. Women;
2. Adults (over 18 y.o.) (preference 18-50 y.o.);
3. Phototypes I to IV;
4. Melasma epidermal or mixed (exclude dermal melasma);
5. Ready to protect as much as possible from the sun for the duration of the study;
6. Ready to avoid contraindicated products (irritants, other depigmenting agents);
7. Participants demonstrating understanding of the study procedures, restrictions, and willingness to participate as evidenced by voluntary written informed consent and having received a signed and dated copy of the informed consent form.

Exclusion criteria

1. Subjects with dermal melasma (wood lamp at inclusion);
2. Subjects who has already use of hydroquinone 4% in the past year;
3. Subjects with stable hormonal therapy (contraceptive ou THS) for at least 6 months;
4. Pregnant or breastfeeding women or pregnancy plans;
5. Subjects applying irritants (such as peeling, acid..) (2 weeks wash out);
6. Subjects under active treatment of melasma (including topicals or procedures) within the last 2 weeks;
7. Subjects using drugs that can induce melasma such as antiepileptics (1 month wash out);
8. Subjects using other products claiming a depigmenting activity (1 month wash out);
9. Subjects with other dermatosis of the face or known photosensitivity;
10. All types of topical treatment applied to the face (wash out of 2 weeks)
11. Subjects without any facial procedure planned during the course of the study
12. Subjects under phototherapy (1 month wash out)
13. Subjects hypersensitivity to the products of the study
14. Any history of significant dermatological/ophthalmological diseases or conditions or medical conditions known to alter skin appearance or physiologic response (e.g. diabetes,) which could, in the opinion of the Investigator, preclude topical application of the investigational products and/or interfere with the evaluation of the test site reaction
15. Subjects currently using any medication, which in the opinion of the investigator, may affect the evaluation of the study product, or place the subject at undue risk.
16. Previous history of atopy, allergic reactions, irritation or intense discomfort feelings to topical-use products, cosmetics, or medication
17. Participation in another clinical study
18. Employee of the sponsor or the study site