Every mark begins with an injury the eye barely registers: a pimple, a scratch, an ingrown hair, a patch of eczema. In lighter skin the inflammation subsides and the surface returns to itself. In deeper skin the same inflammation reaches the melanocytes, the cells that produce pigment, and asks them to do what they were built to do. They respond generously. The result is a spot darker than the skin around it, sitting in the upper layers or, when the injury was deeper, in the dermis itself, where it can stay for a year or more.
This is post-inflammatory hyperpigmentation, and it is the most common reason people with Fitzpatrick types IV to VI visit a dermatologist. It is not damage. It is a protective reflex, the same one that lets melanin-rich skin resist photoageing for decades longer than lighter skin. The trick is not to suppress the reflex but to stop provoking it.
What makes it worse
Three things. Picking, which turns a small injury into a larger one. Heat and friction, which inflame without breaking the skin. And ultraviolet light, which tells the melanocytes to keep going long after the original injury has healed. A dark mark that is shielded from the sun fades. One that is not, darkens.
What makes it better
Patience, first. Then ingredients that quiet the signal between inflammation and pigment: niacinamide, which slows the transfer of melanin to the surface; tranexamic acid, which interrupts the message itself; gentle exfoliation, which clears pigmented cells from the surface without creating new inflammation. And a mineral sunscreen every morning, which is the one step that decides whether anything else works.
Eight weeks is the honest timeline. The first change is tone, a general evening-out. The marks themselves follow. Those who keep the ritual see it. Those who stop at week three rarely do.