Ryan Howard is no stranger to freezing temperatures, having lived through winters in New Hampshire. But standing in a tank chilled to -210 degrees Fahrenheit — while naked, save for socks and gloves — was new even for him.
Howard was dabbling in “whole-body cryotherapy,” a new biohacking trend that involves self-immersing in very cold, dry air at dozens of spas and wellness centers nationwide. Howard’s session in a liquid nitrogen-refrigerated tank wasn’t cheap: three minutes of being a human popsicle cost $55.
“It’s so cold you feel alive,” Howard, who has founded two health technology startups in San Francisco, told BuzzFeed News. “It’s like jumping in a cold pool.”
Cryotherapy devotees say the practice is worth the expense because it can treat all kinds of conditions that, depending where you look on the internet, include Alzheimer’s, anxiety, asthma, chronic pain, migraines, and stress. Other sites claim that a blast of cold reduces inflammation and cellulite, improves skin, and increases metabolism.
But in a consumer alert issued this month, the U.S. FDA warned that there is no evidence to support these claims, at least not yet. (Although researchers are beginning to study it.) And the potential health risks from exposure to extreme cold include asphyxiation, frostbite, burns, and eye injuries, according to the agency.
“Based on purported health benefits seen in many promotions for cryotherapy spas, consumers may incorrectly believe that the FDA has cleared or approved [cryotherapy] devices as safe and effective to treat medical conditions,” said Dr. Aron Yustein, a medical officer in the FDA’s Center for Devices and Radiological Health, in the alert. “That is not the case.”
In October, a 24-year-old woman made national headlines after she froze to death in a chamber at the Nevada spa where she worked.
Yet people remain enthusiastic about the practice, which originated in Japan in the late 1970s, was introduced to Europe in 1982, and has made its way to the US over the last decade.
Howard isn’t afraid of experimenting with the human body: His latest startup, iBeat, is developing a heart-monitoring wearable that alerts 911 in the case of an emergency, and he’s tried out floating in a sensory deprivation tank. So he decided to try cryotherapy this month after an intense weight-lifting session left his muscles sore.
At CryoSF, a San Francisco cryotherapy center, he walked into the chamber unclothed. His head remained above the top of the tank, so as to avoid breathing in air low in oxygen, and he said he still had control of his limbs and could leave through the chamber’s door if he wanted.
“You’re obviously not going to freeze and break off,” Howard said. “You’re fine, you’re just really effing cold. Think about the coldest you’ve ever been outside in a storm in the Northeast — it’s that bone-chilling cold and you warm right back up.” And the experience seemed to have the intended effect as soon as he warmed up again: “The muscle soreness seemed to be gone very quickly.”
As for the concerns raised by the FDA, Howard isn’t rattled. Just because cryotherapy is new and unstudied, he says, doesn’t mean it’s dangerous.
He’s not alone, especially among Silicon Valley biohackers. George Burke, who runs a group called SF Peak Performance in San Francisco, took members to a cryotherapy chamber this year and thinks that exposing the body to extreme conditions makes it more resilient. He summed up his feelings about the risks this way: “I’m pretty sure I’ve done a lot worse to my body than three minutes of cold.”
Afag Shukurova, who opened the CryoSF clinic this spring, said that the center requires customers to fill out a waiver, and will not treat them if they have conditions like hypertension, cardiovascular disease, or pregnancy. But the center’s website makes several unproven claims, such as that the practice “helps to reduce inflammation throughout the body and relieves pain in joints and muscles,” burns “400 to 800 calories” in a session, and “helps boost immunity and metabolism.”
“This therapy hasn’t been approved by the FDA,” Shukurova told BuzzFeed News, but added that there is “little to no risk involved.”
Dr. Daniel Vigil isn’t so sure. As an associate clinical professor at UCLA’s David Geffen School of Medicine and a team physician for UCLA Athletics, he routinely has athletes cool their sore muscles with ice packs and soak them in 35-degree water. But whole-body cryotherapy, he says, is something else entirely.
“Three or four minutes, exposed to an environment of -200 degrees Fahrenheit, we don’t know what that does to circulation, to organ function, to neurologic function,” Vigil told BuzzFeed News.
“I’m not aware of any proven benefits, I have no reason to say it’s good for you,” he added. “The flip side is because of the potential risks, I would advise against it.”
The FDA worries that people may be doing cryotherapy in lieu of proven and effective health treatments. According to its consumer alert, they “may experience a lack of improvement or a worsening of their medical conditions.”
Or they may feel nothing at all. Sue Zhou, a pianist in Los Angeles, recently went to a center in Beverly Hills after she read about cryotherapy online. She hoped to relieve her sore muscles after a bruising game of soccer. Plus, she had a coupon.
Which may have been a good thing, because “I absolutely did not see any effects of it, good or bad, afterward,” Zhou said.
But she’d do it again, just to see what would happen — if it were free.
“It’s like $60, that’s ridiculous,” she said. “I can just buy some ice. Or go to a cold place and run around naked.”