Which cosmetic actives should be used to effectively deal with melasma?

Melasma, also referred to as the mask of pregnancy or chloasma, is a form of hyperpigmentation commonly observed in pregnant women (but not exclusively). It is the result of an excessive and localised production of melanin. There are three types of melasma:

• Theepidermal melasmawhich is the most superficial form with hyperpigmentation of the epidermis;

• The dermal melasma that affects the dermis;

• The mixed melasma which is characterised by both an epidermal melasma and a dermal melasma.

The primary causes of melasma are hormonal changesduring pregnancy, following the use of contraceptive pills, hormone replacement therapy, as well as theuse of certain anti-epileptic drugs or even endocrine disorders(for example, thyroid disorders).Repeated solar exposures can exacerbate melasma.

In the realm of beauty, an increasing number of active brightening molecules with anti-spot properties are being developed. Below is a non-exhaustive list of these compounds, whose studies have supported their effectiveness against melasma.

• The niacinamide

  Also known as vitamin B3, nicotinamide, or PP vitamin (Pellagra Preventive), niacinamide is part of the water-soluble B group vitamins with antioxidant, antibacterial, and anti-inflammatory properties. Regarding its anti-spot activity, it inhibits the transfer of the melanosome from melanocytes to keratinocytes. As a reminder, skin pigmentation is a complex process that begins within cells called melanocytes, which themselves contain organelles (the melanosomes) in which melanin is synthesised. There is then a transfer of these melanosomes to the surrounding keratinocytes, which will subsequently transport the pigment and possibly degrade it.

• Thetranexamic acid

  This is asynthetic derivative of lysine, an amino acid found in the skin. Itslightening propertieswere recently discovered by a health professional. Its mechanism of action is based on theinhibition of the release of inflammatory mediators involved in triggering melanogenesis. When applied topically only, tranexamic acidacts on epidermal type melasmas. Thus, according to a study conducted in 2019, a 5% topical solution of tranexamic acid is as effective as a cream containing 3% hydroquinone. Tranexamic acid is now presented as anew safe alternative to hydroquinone. As a reminder, this molecule is a bleaching agent banned in cosmetics since 2001 in Europe due to its carcinogenic potential.

• Theglycolic acid

  Whether of natural or synthetic origin, theglycolic acidisthe shortest of the alpha-hydroxy acids (A.H.A.).Its ability to stimulate the renewal of skin cells allows it to correct skin damaged by UV rays (brown spots), dull skin and to erase the marks left by blemishes. By penetrating the skin deeply due to its small size, it regulates the action of melanocytes during the production of melanin and reduces the appearance of pigmentation spots.

• Thealpha-arbutin

  Derived naturally (from bearberry leaves) or synthetically, alpha-arbutin, also known asarbutin acid, is a relatively new anti-spot active ingredient. When applied topically, its remarkable effectiveness is due to itsperfect affinity with the active site of tyrosinase, an enzyme involved in the formation of melanin. Thus, thiscompetitive inhibitionof the enzyme's active site blocks its activity and consequently the synthesis of melanin.The equation is simple: less tyrosine and less melanin means fewer pigments, fewer brown spots, and a more even complexion.

• Theazelaic acid

  This compound is adicarboxylic acidthat is naturally found in wheat, rye, and barley. It is recognised for its anti-comedogenic, anti-bacterial, and anti-spot effects.The mode of action of azelaic acid against hyperpigmentation has been identified. It reduces the ability of melanocytes to produce melanin by inhibiting the enzyme tyrosinase and by regulating the activity of the enzyme thioredoxin reductase. Moreover, it only targets pigment-loaded melanocytes or atypical melanocytes. Therefore, it does not interact with healthy cells.

• The Vitamin C

  This staple in skincare needs no introduction! Vitamin C (or ascorbic acid) protects against free radicals, smooths tired features, and brightens dull complexions: it's the ultimate radiance-boosting active ingredient. In dermatology, several studies have demonstrated thedepigmenting power of Vitamin C. Its mechanism of action is based on theinhibition of tyrosinase, an enzyme responsible for the conversion of the amino acid tyrosine into melanin, thus reducing pigmentation.

• BUI T. P. & al. Azelaic acid: pharmacokinetic and pharmacodynamic properties and its therapeutic role in hyperpigmentary disorders and acne. International Journal of Dermatology (1995).

• BOISSY R. E. & al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. British Journal of Dermatology (2002).

• BIKOWSKI J. Managing melasma with azelaic acid gel. Practical Dermatology (2008).

• THAPPA D. M. & al. Comparative study of trichloroacetic acid versus glycolic acid chemical peels in the treatment of melasma. Indian Journal of Dermatology, Venereology and Leprology (2010).

• MONCADA B. & al. A double-blind, randomized clinical trial of niacinamide 4% versus hydroquinone 4% in the treatment of melasma. Dermatology Research and Practice (2011).

• TELANG P. S. Vitamin C in dermatology. Indian Dermatology Online Journal (2013).

• MASHOOD A. A. & al. Treatment of refractory melasma with combination of topical 5% magnesium ascorbyl phosphate and fluorescent pulsed light in Asian patients. International Journal of Dermatology (2014).

• WANG J. V. & al. Tranexamic acid for melasma: Evaluating the various formulations. Journal of Clinical and Aesthetic Dermatology (2019).

• BOO Y. C. Arbutin as a skin depigmenting agent with antimelanogenic and antioxidant properties. Antioxidants (2021).

• MOHAMMADAMINI H. & al. A comprehensive review of the therapeutic potential of alpha-arbutin. Phytotherapy Research (2021).