Superman's Body On The Inside Is Inhuman - And Deeply Unsettling

First introduced in the first issue of "Action Comics" in 1938, Superman has become one of the most popular and enduring characters in popular culture, appearing in numerous comic books, television series, and movies. A new feature film, "Superman: Legacy," is coming in 2025, bringing the story of the Man of Steel to the forefront of the DC Universe once again.

When Superman arrives on Earth as an orphan from the planet Krypton, he adapts to Earth's weaker gravity, making him famously "faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound."

While on Earth, he alternates between fulfilling his duties as a superhero and posing as Daily Planet reporter Clark Kent from Smallville, Kansas. But in his decades battling various villains, fans have come to wonder whether his internal anatomy is more earthling or Kryptonian and just what the latter might entail. Fortunately, the films and comics have addressed some of those questions, particularly with regard to his metabolism.

Superman gets his energy directly from the sun, so he does not need to eat for sustenance like humans. However, he is seen gorging on hamburgers after particularly taxing adventures and, on other occasions, eats meals for purely social reasons. One particularly graphic image from the comics shows an X-ray vision scan of Superman's internal organs, which look similar to a human's, with what appears to be a heart, liver, blood vessels, and digestive organs.

Superman was among 12 DC characters who had details of their anatomy published in a dossier

In 2018, DC Comics published "Anatomy of a Metahuman," a dossier compiled by Batman of twelve characters from the DC universe, from Aquaman and Swamp Thing to Doomsday and Superman himself. The book shows detailed drawings of their internal workings and — for Superman in particular — descriptions of how some of his superpowers work, such as his X-ray vision. Many of Superman's powers are simply a product of his adaptation to the weaker gravity of Earth when compared to his home planet of Krypton, like his ability to leap great distances, giving the illusion of flight.

In a thread on the r/AskScienceFiction subreddit, u/RobotFolkSinger observed that Superman had to make necessary social and biological adaptations to survive when he came from Krypton to Earth as a child. "He doesn't need to breathe as long as there's a yellow sun around," they wrote. "Superman can draw energy directly from the radiation of a yellow sun, so he doesn't need to take in oxygen. He probably still does breathe when on Earth, though, so that the people around him don't notice he isn't and get weirded out."

Some users noted his ability to store and discharge massive amounts of air in his lungs. At the same time, fans seem divided on Superman's biological need to breathe like an ordinary human does.At least one user is convinced Superman has to take in oxygen like any native Earthling. According to u/vadergeek, "He needs to breathe, but he can hold his breath for a ludicrously long period of time." Perhaps writer and director James Gunn will provide fans with some more answers regarding Superman's physiology in "Superman: Legacy" when the film lands in theaters.