Spot the Difference: Are Those Adorable Freckles or Unwanted Age Spots? Blog Face Forward Medical Aesthetics 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 How to Tell the Difference Between a Mole and a Freckle Century Medical & Dental Center Scientists Still Don't Know Why We Get Freckles : ScienceAlert