It was advertised for its purported properties fighting tooth decay, attributed in advertisements to the supposed ingredient Irium. Irium is another word for sodium lauryl sulfate, an inexpensive ionic surfactant. However, in a 1994 speech, then-FCC chairman Reed Hundt claimed that the "Irium" mentioned in Pepsodent advertisements "didn't exist".
Another ingredient, "I.M.P." was purported to whiten teeth. Its best-known slogan was “You'll wonder where the yellow went / when you brush your teeth with Pepsodent!” British comedian Jasper Carrott referred to the slogan in one of his stand-up routines, saying “On your tongue - that's where the yellow went!”
Pepsodent was a very popular brand before the mid '50s, but its makers were slow to add fluoride to its formula to counter the rise of other highly promoted brands such as Crest and Gleem toothpaste by Procter & Gamble, and Colgate's eponymous product; sales of Pepsodent plummeted. Today Pepsodent is a “value brand” marketed primarily in discount stores and retails for roughly half the price of similarly-sized tubes of Crest or of Colgate.
In the 1930s a massive animated neon advertising sign, featuring a young girl on a swing, hung on a building in Times Square in New York City. This ad was re-created for the climax of the 2005 film King Kong.
The product was discontinued in South Africa in 1974. The popular slogan was also changed in South Africa to "You'll wonder where the dullness went / when you polish your teeth with Pepsodent".
Bloody Mary's chewing betel nuts
And she don't use Pepsodent.