Melanotan What It Is and Its Relation to Skin Cancer Freckles vs. Melasma: Understanding the Differences Freckles Dr Darren McKeown 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 I accidentally undid years of skin work and didn't realize it until it was too late. At the beginning of November, I started taking melanotan 2 and honestly? I loved it.