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 Professional Removal of Hyperpigmentation My London Skin Clinic Freckles vs. Melasma: Understanding the Differences 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. Freckles Dr Darren McKeown