Fans of far right-wing media are spreading the untrue (and somewhat transphobic) rumor that Burger King’s plant-based Impossible Whopper contains enough of the female hormone estrogen to make cisgender men grow breasts.

The rumor started because of an article written by James Stangle, a South Dakota veterinarian, and printed in Tri-State Livestock News, a publication that generally opposes plant-based meat substitutes as harmful to livestock farmers’ businesses. Stangle wrote, “An Impossible Whopper has 18 million times as much estrogen as a regular Whopper.”

Related: A Christian group is protesting Burger King’s new mental health awareness promotion

The Impossible Burger is made partly of soy, a protein-rich product of soybeans which contains high concentrations of isoflavones. Isoflavones “belong to a class of compounds generally known as phytoestrogens… [which are] similar in function to human estrogen but with much weaker effects,” according to The Washington Post.

New York University nutrition professor Marion Nestle told the publication that Asian men and boys have been eating large amounts of soy for centuries and, “No, they don’t grow breasts.” Any guy who might grow breasts in response to eating large amounts of soy could just have an extremely rare sensitivity to phytoestrogens, she adds.

But that hasn’t stopped right-wing publications and commenters from repeating Stangle’s lie. Conservative news outlets like the National File and MichaelSavage.com have republished articles repeating it as fact, and far-right Twitter users are amplifying the lie with some occasional transphobic comments.

Here are two such tweets:

Dudes..Do you want to grow Breasts?

East the #Impossibleburger. It has enough Estrogen to make you grow those Trans lookin' tits you always wanted!

UH OH!

Boy it sucks that you can't short private companies isn't it?

FLUSHHHHH you can hear the value toilet flushing!#FrogsGay pic.twitter.com/ed7sQMLkw1 — Alpha OmegaEnergy (@AOECOIN) December 26, 2019

Sure, let's turn our boys into girls fast!!! What a great agenda! Social engineering is not enough apparently these days, so let's do it with the food that we eat!https://t.co/86hx0BwUbp — Leonard Roxon (@LeonardRoxon) December 27, 2019

This isn’t the first time that soy has been a bogeyman for “feminizing” men. In 2006, James Rutz, founder of Megashift Ministries and religion columnist for worldnetdaily.com, wrote that soy “commonly leads to a decrease in the size of the penis, sexual confusion, and homosexuality.” However, no studies have ever actually linked the ingestion of phytoestrogens to becoming gay.