Sunspots: What effect does tranexamic acid have on this type of hyperpigmentation?

Solar spots or lentigos are pigmented spots caused by adisruption in the pigmentation process (melanogenesis). The melanin, pigment responsible for the natural colouration of the skin, is overproduced in certain areas which leads to the appearance of brown spots.

As we age, the functions of melanocytes, cells capable of producing melanin, become disrupted. The production of melanin becomes erratic, leading to the emergence of spots or solar lentigines in the most exposed areas (hands, face, décolletage, back, arms...). Even though these lesions are benign, some individuals may find them unsightly and wish to eliminate them. Tranexamic acid is a particularly effective active ingredient for diminishing the appearance of these brown spots.

The exact mechanism of reduction of the melanogenesis by tranexamic acid remains unidentified to this day. However, several key elements have been highlighted by various studies.

• Tranexamic acid inhibits the release of inflammatory mediators (arachidonic acid and prostaglandins) involved in the triggering of melanogenesis.

• It blocks the interactions between melanocytes and keratinocytes (cells of the epidermis).

• Tranexamic acid is structurally similar to tyrosinase, an enzyme that activates the oxidation of tyrosine, leading to the production of melanin. This competitive inhibition of 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.

Thus, through these various actions, skincare products containing tranexamic acid are effective in reducing the appearance of sunspots. It should be noted, this compound should be introduced at a concentration ranging between 1 and 5%.