Yeh, the way lip plumpers work is to irritate the skin on the lips in order to cause an inflammation. This will lead to increased blood flow to the lip area giving the appearance of fuller, plumper and rosier lips. There are certain ingredients that can cause this effect: some essential oils such as peppermint oil, cinnamon oil, clove oil and some spices. Have you ever notice that your lips are plumper and redder after you’ve eaten something spicy? This is because the spices have caused the lips to inflame. Most lip plumpers on the market use some of these ingredients anyway so I just thought it’d be cheaper to make my own! This guy explains it much better: