Our expert says:

Anti-ageing expert

Hello “Mustache”, thank you for the question.

The pigmentation you describe may be related to a type/form of pigmentation known as Melasma or Chloasma. This is characterized by dark confluent and large areas of dark pigmentation typically found on the cheeks, forehead, and upper lip (often described as a “coffee stain” or “moustache”), but may be found on other areas of the face, neck, etc. Predominantly this form of pigmentation is related to hormonal changes seen with oral contraceptives, IVF, and pregnancy, but may also be seen with individuals with no specific hormonal changes. Your best approach would be to consult an aesthetic practitioner or cosmetic dermatologist who can examine the area and give you a diagnosis and treatment regime.

Topical Treatments include:
Stopping the oral contraceptive or any other hormone treatments you are using but only after discussing this with your doctor and an alternative can be used.
Use SPF 30 or higher (my preference is a SPF 50) that contains zinc oxide and titanium dioxide. Apply several times daily and use sun avoidance as much as possible (wear a hat).
Glycolic and/or mandelic acid peels.
Skin depigmenting creams that contain glycolic acid, Malic acid, kojic acid, mandelic acid, mulberry extracts, and Bearberry extracts.

One needs to differentiate between dermal and epidermal Melasma as the use of laser (Fraxel) pigment removal should only be used on epidermal Melasma.