Certs mints invented an ingredient called "Retsyn" just so that they could market themselves as "the only mints with Retsyn."
Certs mint’s trademark slogan “the only mints with Retsyn,” sure does sell. But what exactly does it mean? Why exactly is “Retsyn” so amazing? The answer to that is; it actually isn’t. According to the Certs Cool Mint Drops Page, Retsyn is a combination of partially hydrogenated cottonseed, cooper gluconate, and flavouring. Aka: oil, copper sugar, and a vague but unremarkable chemical.
But while Retsyn itself isn’t amazing, its story sure is. The ingredient (if it can even be called that) was created by Certs mints as a marketing scheme. It was meant to give them a competative edge by making it appear as though they had something no one else did. The most astonishing thing is that it worked! For a long time, Certs has been considered “America’s most popular mint”...which come to think of it would be a more catchy and honest slogan.