As a science teacher, I think evidence is pretty important. Luckily, patents can’t be awarded without evidence, so while there’s not much about plumpers in the published scientific literature, there’s plenty of evidence for plumping that’s been submitted to the patent office! A patent is given for a new invention (including a cosmetic formula) that does what it claims to do, when an application is filed. All applications have to be made public. This means some of the patent applications are a little vague but it’s easy to see which plumpers have been tested and shown to work, because patents aren’t issued for things that don’t work. Here’s some of the scientific evidence relating to lip plumping (click the links to read original reports):