Kojic acid is used in cosmetic products for its action against dark spots and its brightening properties. It is a tyrosinase inhibitor, the enzyme that participates in the production of melanin.

Discovered in 1907 in Japan when it was isolated from the fungus Aspergillus oryzae.

It is considered safe at concentrations up to 1%. It is used in facial cleansers, toners, serums and creams in order to brighten the skin and give a more even tone.

However, It is not particularly stable (oxidizes and discolors) and for this reason companies often use its derivatives such as kojic dipalmitate (ester).

Potential benefits

As I have already mentioned, kojic acid inhibits the action of tyrosinase in the production of melanin. As a result, it may reduce dark spots and acne scars.

Has also antibacterial and antifungal properties.

Possible side effects

Sunburns due to increased skin’s light sensitivity. Kojic acid inhibits the production of melanin which is the pigment that protects the skin against UV rays.

May cause contact dermatitis mainly in people with sensitive skin.

Can be combined with

a- alpha arbutin

Vitamin C (L-ascorbic acid)

Glycolic acid

Niacinamide

As for the retinoids, you shouldn’t use them the same day to avoid damaging your skin barrier.

Precautions

Never ever combine many active ingredients . You risk to  damage your skin barrier with the unpleasant consequences this will have. If you want to learn more about the skin barrier, you can read my related post. https://www.christiannak.com/?p=19. You may also read my post on how to repair the skin barrier. https://www.christiannak.com/?p=69.

Do not skip the patch test for 48 hours.You absolutely need to know how your skin will react to the new active ingredient. You will also see if your allergic to it .

Do not use kojic acid for more than 3 months. Moreover, don’t introduce new active substances in your skincare routine during the summer.

Moisturize and nourish your skin.

Use of broad-spectrum sunscreen SPF50.

In case of severe hyperpigmentation, it would be a good idea to consult a dermatologist. It’s the person with the necessary knowledge to suggest possible solutions.

To sump up, kojic acid has potential benefits against dark spots but you should be very cautious. Always consider the other active ingredients you apply to your skin. More ingredients are not guaranteed to bring better and faster results. On the contrary, they may have adverse reactions.