Your skin is the largest external organ on your body. Some refer to it as a second kidney. The skin is the last organ to receive vital nutrients, yet the first to show signs of imbalance or deficiency. Skin performs many functions including: Protection from the environment, Heat regulation, Control of evaporation, Aesthetics and communication (others see our skin and can assess our mood, physical state and attractiveness), Storage and synthesis for lipids, water and vitamins, Excretion of impurities and Absorption of Oxygen, nitrogen and carbon dioxide. Medicine can be administered through the skin, by ointments or by means of adhesive patch, such as the nicotine patch.