Is This the New Way to Climb Mount Everest?

Picture yourself in your office. Your phone buzzes with a text message: Time to go! You sprint downstairs to a waiting taxi and zip to the airport, where you board an overnight flight to Kathmandu. You land, hop in a helicopter, and soar over the Himalayas to Mount Everest Base Camp, where Sherpas hook you up to oxygen. You and your guides climb the Khumbu Icefall, Western Cwm, Lhotse Face, and continue on to the summit, where you snap a triumphant selfie. You then descend 11,400 vertical feet back to Base Camp, where a helicopter whisks you to the airport, and you board your flight back home. One week after receiving the text, you’re back in your office.

Sounds like a scene from a science fiction movie, right?

In May, an Austrian mountaineer and guide named Lukas Furtenbach will oversee four paying clients on an Everest expedition that, door to door, will last just seven days. That’s about one-third the length of the speediest Everest expeditions currently offered by guiding companies. And it’s much shorter than most guided ascents of the world’s highest peak, which typically last anywhere from six to eight weeks. On those trips, climbers complete multiple acclimatization hikes up the mountain to adjust to the extreme altitude.

“Our type of expedition opens Mount Everest up to people who don’t have enough free time for the traditional experience,” Furtenbach told Outside. “We are confident they will summit. Our reputation is on the line, and our business would be impacted if we fail.”

All four clients are from the U.K., which means they will start their journeys at or near sea level. According to Furtenbach, each client is paying $153,000 for the trip.

So, what’s Furenbach’s secret to speed? In short, xenon gas. A few weeks before traveling to Nepal, Furtenbach’s clients will travel to a hospital in Germany where they will don a diving bell-like mask and inhale xenon gas. Studies have suggested that the odorless gas can protect vital organs from altitude sickness, while boosting the body’s production of erythropoietin, or EPO, the hormone that stimulates the production of red blood cells. When used alongside traditional at-home acclimatization methods, xenon gas can make the human body capable of withstanding Everest’s extreme altitudes, according to Furtenbach.

“We are doing this primarily for safety as a form of preventing altitude sickness,” Furtenbach says. “This is not about performance enhancement.”

The news of Furtenbach’s experimental tour caused a stir in the mountaineering world when he announced it in January, and in the ensuing weeks, the entire industry of guides and expedition operators appeared to wrestle with this new method. Some guides voiced their support of the experimental procedure, others chastised it, while others raised questions about safety. On January 22, the International Climbing and Mountaineering Federation, a global body that advocates on behalf of climbers, published a terse statement condemning the practice.

The ordeal has forced mountaineers and guides to revisit the ethics—or lack thereof—that climbers follow on the world’s highest peak, and to ask themselves how far climbers should go to improve their changes of actually reaching the top, and who belongs on the peak.

“The old adage, ‘Just because you can, doesn’t mean you should,’ applies in this context,” says mountaineer and longtime Everest chronicler Alan Arnette.

Lukas Furtenbach, Everest’s Technophile Guide

Furtenbach, 47, launched his own guiding business, called Furtenbach Adventures, in 2014. He made his first ascent of Everest two years later. These days, Furtenbach Adventures leads trips to 12 of the world’s 14 peaks above 8,000 meters, as well as to the seven summits, the highest peak on each of the seven continents.

His company touts its use of technological innovations that aid safety and summit success. His clients wear devices that track their heart rate and oxygen saturation during climbs. Clients also receive high doses of oxygen—eight liters per minute—on high-altitude ascents. In 2024, he took 40 paying clients to the top of Everest.

“He’s one of the more entrepreneurial guides on Everest,” says author Will Cockrell, whose 2024 book Everest, Inc. chronicles the mountaineering industry. “He’s young and hungry, and seems like he wants to appeal to the wider audience of climbers.”

In 2017, Furtenbach debuted his three-week Everest trip, called “FLASH” expedition, which required participants to use hypoxic tents at home for eight weeks prior to the ascent. The tents produce a low-oxygen environment, and sleeping in one helps climbers prepare for the thin air found in the Himalayas.

Furtenbach himself has acted as a guinea pig to test out his methods, including this new one that relies on xenon. He has personally tested xenon gas on his own body since 2019. That year, a German doctor named Michael Fries contacted him and asked if he’d undergo a test with the gas to see if it impacted his climbing. Furtenbach agreed. One week after the treatment, Furtenbach traveled to Argentina, took a helicopter to the Base Camp of 22,837-foot Aconcagua, and then ascended the peak the next day.

“It was surprising how well it worked—I was feeling so good on the mountain,” he says. “I had no altitude problems.”

Furtenbach saw the potential for using the treatment for Everest expeditions. In 2021, he again underwent xenon treatment prior to Everest’s spring season—he planned to climb the peak alongside his three-week FLASH clients. He ascended 21,247-foot Mera Peak nearby with no problem, then set his sights on Everest. But a COVID outbreak in Base Camp forced him to cancel the ascent.

In 2022, he returned having had xenon treatments. This time, he was not alone—a cameraman and a guide also did the treatment. The trio summited both Mera Peak and Everest with no problems. His door-to-door time from his home in Innsbruck was 16 days. That’s when Furtenbach got the idea for the one-week Everest trip.

“My heart rate and blood-oxygen was the same as guides who had been acclimatizing with altitude tents,” he said. “I knew that with the right logistics and backup of supplemental oxygen, one week was possible.”

Furtenbach planned to do a one-week test on Everest in 2023, but a film project involving him torpedoed that timeline. He targeted 2024, but again faced setbacks, when his two clients for the experimental trip backed out due to scheduling issues. So Furtenbach again tested it on himself, and ascended Everest from Tibet.

“This was my fifth time testing, and we could see an increase in my hematocrit of 10 percent,” Furtenbach says, referencing his blood’s percentage of red blood cells. “That’s about what you’d get after spending the traditional eight weeks at altitude during an Everest expedition.”

Can Xenon Gas Improve the Body’s Performance at Altitude?

During a xenon treatment, Furtenbach sits in a medical room and dons a mask attached to a ventilator. At first, the device pumps out pure oxygen, but over a 30-minute period, it gradually adds in xenon.

“You start to feel a little bit dizzy, but it doesn’t feel bad, and you don’t taste or smell anything,” Furtenbach says. “After 25 minutes or so, you turn it off and feel perfectly normal, like nothing has happened.”

But whether or not the gas actually helps the human body on the world’s highest peaks is still open to debate. Research into the impact of inhaled xenon on humans is still in its infancy.

In 2014, The Economist published a groundbreaking report about the Russian doping program during the Socchi Winter Olympics. The report stated that Russian athletes inhaled xenon to produce EPO and boost their blood’s ability to transport oxygen. Decades ago, pro cyclists injected synthetic EPO before competing in the Tour de France. The World Anti-Doping Agency (WADA) officially added xenon to the list of banned substances for Olympic competition that year.

Two separate experiments, conducted in 2016 and 2019, sought to quantify just how much inhaled xenon could increase the body’s ability to carry oxygen. Both studies showed that inhaling xenon caused the human body to ramp up its production of EPO and also blood plasma within a few days of treatment. But neither study could conclude if this led to an uptick in actual human performance.

The 2019 study concluded: “Xenon inhalation did not increase fitness or improve athletic performance, and, given the adverse symptomology associated with dosing, our findings do not support the use of xenon as an erythropoiesis-modulating agent in sports.”

Furtenbach also points to other potential qualities of xenon—specifically, that the gas may prevent high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). Dr. Fries’s research suggests that xenon protects the brain and lungs in low-oxygen environments. But Dr. Friese’s experiments were conducted on animals. Critics point out that these tests are also inconclusive.

“His studies are interesting, but they’ve never been done on humans in protection from hypoxia,” says Dr. Peter Hackett, a mountaineer and expert in high-altitude research. “It’s a big leap from studying rodents and pigs to applying it to humans.”

But Furtenbach says that his own tests on himself have convinced him that xenon works. He told Outside that the day after undergoing xenon inhalation in 2019, he did his normal ski touring ascent at home in Innsbruck. “I was seven minutes faster without putting any effort into it,” he says. “We measured my hematocrit and could see the increase within five to eight days was dramatic.”

Plus, Furtenbach says, the xenon treatment simply supplements the tried-and-true acclimatization that his FLASH clients already complete before tackling Everest. Like the three-week FLASH clients, Furtenbach’s one-week clients will spend eight weeks sleeping in an altitude tent prior to the expedition. They will also complete a series of hypoxic athletic workouts prior to the trip.

“Xenon is just one component,” he says. “With acclimatization using hypoxic systems, one can achieve the same or even higher acclimatization than would occur at real altitude on the mountain.”

Critics Sound Off on Xenon

Furtenbach first spoke to Outside in December 2024, and predicted that his idea would likely ruffle feathers in the small world of Everest guides.

“I know there is going to be criticism,” he said. “People will say it’s doping. People will say it’s not real mountaineering anymore.”

The pushback was even harsher and more substantial than he predicted. On January 22, the International Climbing and Mountaineering Federation released a statement condemning the use of xenon. The statement called into question the science behind xenon’s use for acclimatization, and also pointed out the ethical dilemma of using a substance that’s banned by WADA. “Acclimatization to altitude is a complex process that affects the various organs/systems such as the brain, lungs, heart, kidneys and blood to different degrees, and is not fully understood,” the statement read. “Since the physiological changes take days to weeks to influence the organism, from a physiological point of view, a single, one-off drug cannot be the key to improved acclimatization or increased performance.”

But not everyone in the climbing world is as critical. In an interview with Austrian news site Der Standard, mountaineering legend Reinhold Messner, the first person to climb Everest without supplemental oxygen, called the method “fantastic.”

“I think it’s brilliant of Furtenbach to have realized what xenon can do for high-altitude mountaineering,” Messner said. “I congratulate him on his success.”

Furtenbach shrugged off the ethical questions over using the substance. WADA rules do not apply to mountaineering, and clients and guides already use a wide array of substances to artificially enhance their performance on the mountain, most notably bottled oxygen. Some mountaineers also bring an anti-inflammatory steroid called dexamethasone—or DEX—on expeditions to mitigate symptoms of altitude sickness.

Furtenbach claims xenon isn’t doping, but rather a protective measure similar to bottled oxygen.

“We are paid to be responsible and to care about the lives of our clients,” he said. “We have to do everything we can to make the climb as safe as possible. And if using oxygen or other gasses makes the client safer, then that’s what we will do.”

Still, the climbing federation wasn’t the only body to criticize Furtenbach’s use of xenon. Throughout January, other Everest guides also chimed in with pushback on the new method. New Zealand guide Guy Cotter told Outside that he viewed ascents using xenon to be “no more than a stunt.”

“My feeling about this new proposal to use xenon to dope up for Everest is ‘why all the rush?’” Cotter told Outside in an email. “An ascent of Mount Everest, when done properly, is one of the most amazing adventures on earth.”

British guide Kenton Cool told The Financial Times that, while he respected Furtenbach, he would not recommend the method to his clients. “Maybe it’s a reflection on modern-day society, where we want everything yesterday, and nobody’s willing to wait,” he said.

American guide Garrett Madison echoed that sentiment. Madison also offers rapid guided ascents on other peaks. But he said that the traditional six-week tour to Everest offers much more to climbers than just a moment spent on the summit.

“The tried-and-true ascent is a spiritual journey,” Madison told Outside. “You soak up the culture of Nepal and the culture of the Sherpa people and you get to really know this amazing environment. I wish expeditions could last longer.”

Madison said the week-long trip is just the next step in Everest’s evolution as a bucket-list travel destination. “Why not just fly up there in a helicopter and touch the top so you said you did it?” he says.

Furtenbach pushed back against the criticism in a series of emails with Outside: “For those with the time and flexibility to spend eight or ten weeks on an expedition, I congratulate them on the opportunity to immerse themselves in a new culture and environment at their own pace,” he wrote. Furtenbach Adventures also offers the traditional eight-week trip to Everest, as well as the three and now one-week tours, he pointed out.

“Everyone should be free to choose their expedition style and duration, with tolerance for differing approaches, provided no one else is harmed or endangered,” he added.

But there are lingering questions about whether or not rapid trips up Everest increase the risk. Guides who spoke to Outside stressed that patience on Everest is often a virtue, especially in years when the weather presents challenges. These days, hundreds of climbers surge onto the mountain at the same time to make the most of narrow windows of good weather. Climbers on traditional eight-week ascents can wait out the crowds.

Guides also said that acclimatization hikes on Everest give a client “mountain sense,” which can come in handy during an emergency. “There’s a lot to be gained by going onto the mountain in terms of overall preparedness,” Madison said. “You adapt to the cold and the wind. You learn the route. You get a sense of where you are on the mountain.”

Experts also expressed concern that climbers on rapid ascents may have a lower chance of survival if they were to lose access to bottled oxygen above 26,000 feet—the so-called “death zone.” At that altitude, climbers no longer breathe in enough oxygen to stay alive.

“A climber that’s been on Everest for six weeks and has done multiple rotations to Camp II or Camp IiI—if their oxygen runs out, they will be in trouble but they won’t die as quickly,” Dr. Hackett said.

Furtenbach disagreed and argued that at-home acclimatization is just as good as doing so on a mountain. Furtenbach said his clients will be hooked up to oxygen “as soon as it makes sense,” and that the four climbers on the one-week expedition would have a one-to-one or two-to-one guide-to-climber ratio. This high ratio, he says, will ensure that clients always have access to oxygen, and have the help they need in case of an emergency.

And Furtebach also pushed back on fears that Everest’s route will someday be clogged with climbers who are on rapid ascents. The expensive trips, he says, will always cater to a small number of climbers.

“The one-week expedition will always be a niche offering,” he wrote in an email. “It is decidedly not suitable for everyone and requires such extensive preparation, logistics, and financial resources that it could never become a mass-market product.”

Why Are Rapid Everest Ascents Becoming Popular?

Furtenbach’s one-week ascent represents the latest chapter in the ever-evolving history of guiding on the world’s highest peak.

In Everest Inc., Cockrell chronicled the rapid rise of Nepali-owned guiding businesses on Everest and other 8,000-meter peaks. Companies like 8K Expeditions, Asian Trekking, and Seven Summit Treks now dominate the guiding industry on Everest, in part because they offer low-cost alternatives to expeditions led by European and North American guides.

Clients can now get a shot at the Everest summit for less than $40,000 with a Nepali outfitter, versus double that with a western guide. Some Nepali companies now bring between 50 and 100 clients to Everest each year.

“Western guides absolutely recognize how hard it is to be competitive with the Nepalis,” Cockrell says. “They have to fight for their existence on the mountain, and one way to do that is being more innovative.”

Cockrell views the rise of faster expeditions as a result of the market dynamics. Furtenbach, as well as British-American guide Adrian Ballinger, offered some of the first rapid ascent using pre-acclimatization technology. Furtenbach led trips to 26,846-foot Cho Oyu and 26,414-foot Broad Peak in 2006 and 2007 that required climbers to use tents. In 2012 Ballinger led a trip up Makalu that lasted just one month, which was remarkably fast at the time. Ballinger had his clients acclimate at home by using hypoxic tents. Ballinger began offering similar speed trips up Cho Oyu and then Everest. Other western guiding companies followed suit.

“The Nepalis are doing such big numbers on these peaks, so it makes sense that other companies are going to target the high-end clients with different types of trips,” Cockerell says. “Innovation is always going to be more expensive by default.”

The proliferation of different durations—and different price points—for Everest trips, Cockrell says, is a sign that the mountain is rapidly being opened up to a wider swath of climbers. Gone are the days of the eighties and nineties, when only experienced mountaineers—or the extremely wealthy—dared to scale the peak. Like marathon running, or Ironman triathlons, climbing Everest is quickly becoming an activity for the masses.

“There’s still no easy way to climb Mount Everest—climbers are going to suffer their way up it one way or another,” Cockrell says. “What guides and companies have done is to create different versions of suffering. And they can accommodate a wide swath of people.”

“But no matter what, they still have to come down the same way Reinhold Messner did,” he says.