Investigating the Middle School Rumor that Mountain Dew Lowers Your Sperm Count
Illustration by Katherine Killeffer


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Investigating the Middle School Rumor that Mountain Dew Lowers Your Sperm Count

One of the greatest rumors in middle school was that the yellow dye in Mountain Dew killed off your sperm. Naturally, it became a much beloved contraceptive choice for countless teens. Was there any truth to the rumor?

The year was 1999 and teenage boys were under a spell cast by Mountain Dew. Rumors flew that one of the very popular soda's synthetic food dyes decreased sperm count; as a result, some sexually-active teens began binge-drinking the alleged spermicide as their only form of birth control. That year, the rumor gained so much traction that the Wall Street Journal published an article chronicling susceptible teens' belief in it.


According to the urban legend, the soda lowers sperm count and thus works as pre-coital contraception because of the soda's dye, Yellow No. 5, also known as tartrazine. The US Food and Drug Administration approved the dye in 1969, and soda producers have included the dye in Surge, Fanta Pineapple, and Gatorade, among others. (Pepsi Cola produces both Gatorade and Mountain Dew; they did not return Broadly's request for comment.) Despite the ubiquity of Yellow No. 5 in orange-hued beverages, it was Mountain Dew that reigned supreme as the contraceptive of choice for teens—despite the complete lack of evidence regarding its efficacy. Nearly two decades later, many millennials still wonder: Did Mountain Dew really lower sperm count, or were teen boys just attempting to use the baseless rumor to their advantage?

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Scientists at the University of Oran, Algeria conducted an experiment on the impact of tartrazine on mice's sperm count in 2009. The study found that sperm count decreased and sperm abnormalities increased in the group of mice that drank excessive amounts of tartrazine. However, scientists have yet to carry out the experiment on human subjects, and there are no known reported cases of reduced sperm count after drinking Mountain Dew. Additionally, when the European Food Safety Authority reevaluated the effects of Yellow No. 5 in 2009, they found that "there were no indications of [Yellow No. 5]-related adverse effects on reproduction or development." Scientists regard the dye as safe for human consumption, and it has since remained in Mountain Dew.


Experts and volunteers have also tried to debunk the myth on a larger scale. In 2000, longtime Planned Parenthood volunteer Marjorie Saltzman asked Dear Abby to address the claims in a letter. "Let me go on record as stating that Mountain Dew—although a refreshing and enjoyable beverage—is NOT A CONTRACEPTIVE," Abigail Van Buren wrote in response. "It may give the drinker a 'buzz' because of its sugar and caffeine content, but it will do NOTHING to lower the sperm count."

Sean Prichard, a Mountain Dew expert and former director of communications at the Association of Reproductive Health Professionals (ARHP), says that the rumor may have encouraged unsafe sex among young straight men and women. "I think my colleagues, like me, thought the whole thing was hilarious and weird, but also we all saw the opportunity to teach about birth control that actually worked," Prichard tells Broadly. "There is a pretty low percentage that any given sex act will result in a pregnancy, so when a couple [believes] that Mountain Dew is actually working in preventing conception, in reality, it's just statistics."

It's impossible to know how many births resulted from chugging the so-called "rocket-fuel" before sex, but teens definitely fell for the rumor. Karissa Johnson, who attended high school during the height of the Mountain Dew myth, says that at least one girl in her hometown of Huntington, West Virginia, got pregnant after trying to use the soda as contraception. "There was this couple in high school—the first to have a baby—who swore for a year that because of his Mountain Dew intake, they had nothing to worry about," she says. "And it wasn't just them [who believed the rumor], either."

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Johnson's account mirrors the air of naiveté recorded years earlier. In 1999, Kristen Hayes told the Wall Street Journal that classmates were serving each other six packs of Mountain Dew before intercourse. The pervasiveness of the Mountain Dew urban legend, and its resulting impact on teens' sexual behavior, could speak to a lack in access to birth control or accurate information on sexual health and human biology in the American education system: In 2008, lawmakers in Florida pushed for a more comprehensive approach for sex education following a survey that indicated teens believed drinking a shot of Mountain Dew would prevent pregnancy.

"If you're healthy, you're making millions of sperm per month, and hundreds of billions over the course of your life. Not having enough sperm is really going to be the least of your problems," Prichard says. "My guess is when people don't want to use protection, they'll say anything and they'll believe anything."