We all know that when we swish minty mouthwash around in our mouths we feel cleaner and more confident because we are removing odors and nasty germs. Unfortunately, the downsides of this outweigh the advantages. For example, if you are one to suffer from a dry mouth or ulcers, using a typical alcohol-based mouthwash can make these problems worse. Mouthwash containing alcohol actually dries out the tissue in the mouth as they evaporate. This may lead to a minty mouth but an irritated one too. Another disadvantage of using an alcohol based mouthwash is when you consume favourite beverages such as soda, red wine, coffee and tea they will actually stain your teeth more easily. The alcohol in the mouthwash means that your teeth and gums are losing protective mucus and saliva and this can actually lead to an ongoing cycle where your teeth build up plaque more easily causing decay and bad breath at a faster rate.
Commercial mouthwash is especially bad for you because in order to make the product shelf stable, manufacturers add acidic stabilising agents. This acid will eat away at your tooth enamel making you more at risk of decay.
Away from alcohol and acid, there are artificial food dyes being used in most over the counter mouthwashes. For example, Cool Mint Listerine contains the dye Green 3. This has been linked to bladder cancer.