Instagram influencers are sunning their naked butts, but should you?

"Perineum sunning" is catching on with Instagram influencers, but is it safe to butt-chug sunlight?

Jackson Ryan Former Science Editor
Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
Jackson Ryan
3 min read

As CNET's science editor covering the intricacies of climate change, wrestling with the infinite complexity of the universe and explaining the medical advances putting humans in suspended animation, I'm used to being surprised by the wonders of the scientific endeavor. But sometimes you come across articles and ideas that go beyond "surprise." Put simply, they're bonkers. 

"Perineum sunning," the latest craze sweeping through Instagram influencer feeds, feels like one such bonkers idea. 

For those not in the know, perineum sunning is the act of lying on your back completely naked and throwing your legs up in the air, your private bits and pieces pointed directly at the sun. The "perineum," a region of skin between the anus and the scrotum/vulva, is then exposed to the sun's UV radiation. The claims, by some Instagram influencers, is this practice gives you the same amount of sunlight in 30 seconds that you would usually receive from an entire day being outside with clothes on.

The extremely evocative language used by Twitter user @sisterofonline ("butt-chugging sunlight") brought the wellness practice to a more mainstream audience after a viral post gathered steam. 

The viral tweet used a photo and caption from Instagram user @metaphysicalmeagan, showing herself fully naked and pointed at the sun. The caption claims it's an ancient Taoist practice that's been around for a while, that Meagan practices it for a maximum of 5 minutes in the morning and it's "more energizing than slamming cups of coffee." 

A whole raft of health claims follow in the caption, including the idea that sunning the gooch provides "surges of energy almost immediately" and "better sleep," in addition to "attracting soul tribe & people who are on the same frequency and wavelength as me."

In a follow-up, @metaphysicalmeagan shared a video admitting she "never claimed that [pernieum sunning] is backed up by scientific studies, at least not yet" -- and that's an important point to make. However, as a result of this small batch of influencers pointing their behinds at the sun, "perineum sunning" has taken social media by storm, with the reactions ranging from eyebrow-raising to straight-up disbelief and confusion to revelatory admissions of its benefits.

Is there any science at all to back up these claims?  

There are well-known benefits of sunshine in regards to vitamin D synthesis. The sun is able to kick-start a production cascade in the skin that ultimately provides the body with the hormone, which is necessary for calcium regulation and maintaining bone health. But this process occurs because ultraviolet (UV) radiation penetrates the cells of the skin. However, UV radiation can cause skin cancers and thus, prolonged sun exposure is detrimental to health. Genetic factors are one of the main driving factors for skin cancer risk, but UV exposure increases the likelihood of getting melanoma, the most severe form of skin cancer. 

Noted obstetrician-gynecologist and New York Times contributor Jen Gunter, who frequently writes about women's health, wrote a pretty sharp rebuttal Wednesday on Twitter.

Searching the National Institutes of Health database of medical journal articles turns up no results for "perineum sunning" and one article for the terms "perineum vitamin D" (though it's completely unrelated to butt-chugging sunlight). Unless there're particulars of the perineum, the anus and all the other bits scientists and health care professionals are yet to discover, it's unlikely these body parts can absorb energy from the sun any better than the rest of the human body.

We've seen the butt get a lot of play in the wellness space before. Gwyneth Paltrow's oft-maligned Goop wellness site once suggested coffee enemas could help clear toxins from the body. There's no scientific evidence to back up such a claim, either, and scientists have even suggested the enemas could result in severe burns or death.

It's probably a good idea to stick with the expert opinions on this one -- and definitely don't go overboard on the bum sun unless you're keen for a burnt backside.

Watch this: I got my face professionally scanned for wrinkles and UV spots