You can also get the appearance of a black tongue if you use a chlorhexidine mouthwash (these are often uses to treatmouth ulcersor other mouth infections) or the medicine type antacid that has bismuth. If you think your medication may be causing a black tongue, you should continue taking ...
It depends on the mouthwash you are using. There are many over the counter alcohol based mouthwash’s that I feel can affect your health if used frequently in a negative fashion. Right off the bat if I mouthwash has alcohol in it this has been shown to be a carcinogen in many studies...