Sunbathing your derrière is the bizarre ancient wellness trend that’s all over Instagram. We get to the bottom of it…

Some have praised the social media savviness of Metaphystical Meagan and others like her: “on the one hand that is the dippiest naked yoga practice I’ve ever seen,” said @ringcycles. “On the other, [they] likely gained 8k new followers from that post. You can’t buy that kind of, um, exposure.”

And others seem ready to indulge in a little bum-bathing (that’s bum sunbathing) of their own: “I wonder if I could do this w my SAD lamp? [sic]” said @hunnylord. “Life is short, sun yr buns if ya want to [sic]” concurred @e_lee_sule.

To remove any confusion and guide others in their bum-bathing endeavours, Metaphysical Meagan also posted a deeper dive into the dos and don’ts of the practice. “The intention is not to tan your butthole!” she said. “Sunscreen is not required & all you really need is 30 seconds of sun exposure,” she added, with the hashtag #ButtholeSunning. “Mantak Chia speaks about this in his work, as does my friend @ra_of_earth.”

But – safety first – to clarify the scientific advantages of sunning your nethers, we consulted a GP to get the low-down on “perineum sunning” before anyone lies back and thinks of England.

A leading medical expert (who asked not to be named) told us, “Obviously sun rays give you vitamin D [which can help keep bones and teeth healthy]. That said, you’d be exposing an area of your body that is never normally exposed to the sun, which can increase the likelihood of skin cancer.” As for its ability to increase energy and strengthen organs, she dubbed it “unlikely”.

And TikTok’s favourite dermatologist, Dr Dustin Portela took to the platform to clear up his own thoughts on the matter. “The claims made in these videos have absolutely no evidence,” he says. “You don’t need to sun that really sensitive area.” Also, he adds “we literally evolved to walk upright where that area doesn’t get sun, so you shouldn’t be turning it up toward the fireball in the sky in order to expose it.” Most concerningly, he revealed “I’ve removed skin cancer from people: around the anus, on the vulva, on the penis. You don’t want cancer around that area and, definitively, putting sun on that area, you’re highly likely to get burned if you’re doing that because it’s an area that doesn’t get a lot of sun exposure, and that’s going to increase your risk of skin cancer.” He concludes, “don’t do perineum sunning. It’s a stupid idea.”

So there you have it, your behind isn’t a solar panel after all, and charging it up like a Sony Walkman sadly won’t enable you to store energy in your rear end to power you through the day. That said, for many, nakedness can encourage feelings of liberation, so as far as your sexual libido goes, you do you. Just, maybe skip the risqué butthole sun salutations.

For more from GLAMOUR’s Beauty Editor, Elle Turner, follow her on Instagram @elleturneruk