Freckles, Lentigos, Melanocytic Nevi, and Melanoma Springer Nature Link Why don't I have freckles while my parents and brother and various aunts and uncles do? The Tech Interactive Are Freckles on Lips a Cause for Concern? Causes, Remedies Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns Freckles develop when specific skin cells produce extra melanin in response to sunlight. When ultraviolet rays reach the skin, melanocytes release melanin to protect deeper layers from damage. In some people, certain