What is hyperpigmentation? When there is an injury to the skin such as acne or sun damage, the skin instinctively tries to renew itself. In so doing, it also ends up producing more melanin than needed. Melanin is the naturally-occurring pigment present in the skin and hair. Too much melanin production is what leads to hyperpigmentation, scars, and freckles. Sun exposure is also responsible for promoting hyperpigmentation.