Fastest Ascent on World’s Highest Peak: How 4 Brits Reached Everest in 3 Days Using a Mysterious Gas

What usually takes climbers 6 to 8 weeks was reduced to less than a week by four British men. Their whirlwind expedition began in London, reached the 29,000-ft summit of Everest, and wrapped up back home — all in just six days, shattering expectations of what's possible in extreme altitude climbing.

The team’s game-changing secret? Inhaling xenon gas. This rare, odorless gas has been shown to activate a molecule called the hypoxia-inducible factor (HIF), which mimics the body’s natural adaptation to low oxygen — the very process that usually takes weeks on the mountain.

The stunt has stirred backlash in the climbing community. Veteran mountaineers say it undermines the spirit of Everest — turning a symbol of endurance into a “bucket list” activity for the rich. Nepal’s tourism officials have launched an investigation, calling the gas use “against climbing ethics.”

While some experts believe xenon could potentially help the body prepare for high altitudes, others are skeptical. Researchers say there’s little concrete evidence proving it enhances performance — and warn of potential dangers, like accidental overdose, since xenon acts like an anesthetic.

The climbers spent 10 weeks sleeping in hypoxic tents to simulate high-altitude conditions. But their edge came two weeks before the climb, when they visited a clinic in Germany where a doctor administered controlled xenon doses via ventilator masks — a method never before used this way in mountaineering.

Once they landed at Everest base camp, the ascent to the top took just under three days. That’s a blistering pace, especially for climbers not acclimatized on the mountain itself. For comparison, the average non-acclimatized climber would risk severe altitude sickness — or death — without gradual ascent.

Despite the fast timeline, the expedition still employed five Sherpas to guide and assist the team — highlighting that even with futuristic prep methods, local expertise and support remain vital for survival and success on Everest.

Lukas Furtenbach, the expedition organizer, says this is just the beginning. He plans to launch commercially guided, two-week Everest trips starting in 2026, using xenon gas to bypass the traditional acclimatization phase. He’s calling it the future of commercial mountaineering.

Xenon has been banned by the World Anti-Doping Agency since 2014, but because mountaineering isn’t a competitive sport, the ban doesn’t apply. That loophole is raising alarms about unregulated enhancements creeping into high-altitude adventure tourism.

The controversy touches a deeper nerve: Should the most iconic climbs be “conquered” in fast-forward? Critics argue that speed and ease erase the physical and mental transformation that comes from the struggle. One expert asked: “Are we missing out on the joy that only comes through sacrifice?”