“In the lowest layer of our skin, we all have melanin-producing cells called melanocytes,” explains Caroline Robinson, MD, a board-certified dermatologist and CEO of Tone Dermatology in Chicago. “The melanin is carried around the skin in structures called melanosomes and is transferred to our skin cells (keratinocytes). The type of melanin and the size and distribution of melanosomes determines skin color.” She notes that excess pigment production—hyperpigmentation of any kind, whether it’s dark spots, redness, or anything else—occurs any time inflammation occurs on the skin. This inflammation has any number of causes, including acne, eczema, trauma, allergic reactions, and sunburns. “Inflammation tells the body’s melanocytes to produce more melanin, leading to darker spots on our skin,” she says. “Inflammation can also cause melanin-producing cells to send more melanin to our skin cells. If the inflammation is significant enough to damage the deepest layers of skin, it can trigger our pigment cells to spill melanin into the surrounding skin and tissue. This last type of pigment, called dermal melanosis, is particularly resistant to treatment.” According to Dr. Robinson, the primary cause of widespread discoloration is chronic sun exposure, which can directly activate our skim cells to produce more pigment. She also recommends active botanicals like kojic acid, azelaic acid, mulberry extract, or licorice, all of which block tyrosinase as well. Dr. Robinson says that tranexamic acid is a unique ingredient when compared to other brightening compounds, because it has a one-two punch: it prevents the brown spots and calms redness. You should also keep an eye out for niacinamide, a star active derived from Vitamin B3, in addition to alpha hydroxy acids (AHAs) such as glycolic acid, lactic acid, and mandelic acid. These are helpful in treating dark spots by gently exfoliating and bringing pigment to the surface. Now that you know what causes dark spots and what ingredients to look for, here are some products you can invest in for regular maintenance at home.
