How to Tell the Difference Between Freckles, Sunspots, and Moles Your body already makes a hormone that tells your skin to tan. Melanotan 2 is a synthetic peptide engineered to mimic that hormone but in a version that's more potent and Sooo this feels vulnerable to share. I've been taking a very small dose of Melanotan 2 peptide to help build a tan and the last few days I've worn zero 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 Melanotan What It Is and Its Relation to Skin Cancer