Vicks First Defence is a medical device that is clinically proven to help you in the fight against common cold viruses. How Vicks First Defence works: 1.TRAP: The micro-gel formula physically encapsulates (traps) the cold virus in the nose and helps to prevent it from developing and spreading. 2.INACTIVATE: The cold viruses are trapped in the micro-gel and inactivated, reducing their ability to multiply and spread 3.REMOVE: Then, it flushes the nose to help naturally remove the inactivated virus (toward the stomach or by blowing one's nose). Use it at 1st signs of a cold to help reduce the risk of developing a full blown cold or you can even start using it when exposed to cold viruses!