Appliance of Science: How and why do we get freckles? 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 Freckles Dr Darren McKeown 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.