To assess the ability of a new 4% Hydroquinone formulation (Melanoderm 4% Crema) to reduce melasma on the face, using a split-face randomization design, evaluating the MASI Score from baseline to week 4 and week 8, in both half-faces receiving active treatment vs. placebo.

To assess the tolerance of a new 4% Hydroquinone formulation (Melanoderm 4% Crema) on the face.

To assess patients' satisfaction regarding Melanoderm 4% Crema after 8 weeks.

Inclusion Criteria:

• Adult women aged between 18-65 years old.
• Fitzpatrick phototypes I to IV.
• Presenting moderate to severe facial melasma facial, with a basal Melasma Area and Severity Index (MASI Index) between 10 and 20.
• Women of childbearing potential must use an adequate contraceptive method to avoid pregnancy and must have a negative pregnancy test in a maximum of 72 hours before receiving the trial treatment.
• Breastfeeding women will not be included in the study.
• Having given freely and expressly her informed consent.

Exclusion Criteria:

• Those with any history of allergy or hypersensitivity to a cosmetic product, hydroquinone, or one of the ingredients of the investigational products.
• Fitzpatrick phototype V.
• Skin pigmentation diseases different to melasma.
• Evidence of active cancer disease or diagnosis of cancer in the last year.
• Those receiving any topical or oral treatment that could interfere with melasma.
• Pregnant or breastfeeding women, or those expecting to get pregnant during the study.
• Evidence or suspicion of low compliance with the study visits and procedures.
• Participation in other clinical trial simultaneously or in the previous 3 months.