15 Signs and Symptoms of Vitamin C Deficiency Here's the part nobody explains when they're selling you the "Barbie drug.", Melanotan 2 is a synthetic peptide that mimics alpha MSH a hormone your body already makes to tell your skin cells to Vitamin B12 deficiency symptoms: Sores and spots on lips could signal lack of B12 Express.co.uk Vitamin B12 deficiency: Lip symptoms can include dryness, redness or angular cheilitis Express.co.uk