Xenon makes up less than one part in ten million of the atmosphere. Extracting it means distilling liquid air, which is why a single therapeutic session costs a few hundred euros — the gas itself is the expense. It is chemically inert, biologically it is anything but: it blocks the NMDA receptor, the same target ketamine acts on, and it does so without the dissociative profile.

Soviet and then Russian anaesthesiology took xenon seriously from the 1990s onward, both as a surgical anaesthetic and, at lower concentrations, as a therapy for anxiety, withdrawal, insomnia and fatigue. That tradition never crossed into Western practice — not because it was tested and rejected, but because the Cold War split medical literature into two libraries that rarely read each other. Europe approved xenon as a general anaesthetic in 2007 under the name LENOXe. The US never did.

Then there is the patent problem. Modern drug approval is financed by the expectation of exclusivity: a company spends hundreds of millions on trials because a patent lets it recoup that. Xenon is element 54. No one can own it. So the trials that would settle the question have no sponsor, and the question stays open indefinitely — which is not the same as being answered.

Hamilton Morris covered exactly this tension in Hamilton's Pharmacopeia, Season 3, Episode 3 — "Xenon: the Perfect Anesthetic?" — examining why a gas with a strong safety profile in surgical use has remained a curiosity rather than a treatment.

There is no US clinic offering therapeutic xenon that we could verify. Providers are concentrated in Serbia, Russia and the Czech Republic. Three are listed in the directory with their own entries: Swiss Medica (Belgrade — xenon as an adjunct to stem cell therapy), Kivach Clinic (Karelia, Russia — the established Russian tradition), and Dr Vorobjev Clinic (Belgrade — addiction treatment, €300 per session).

One finding that belongs here rather than buried in a listing. Two of the clinics offering xenon also offer ultra-rapid opioid detoxification under anaesthesia. The American Society of Addiction Medicine states this is "NOT recommended due to high risk for adverse events or death". The CDC investigated one New York clinic performing it and documented two deaths and five hospitalisations among 75 patients in nine months. Neither clinic's page mentions mortality risk. That is a counted outcome, not a regulatory opinion, and it would sit in this Charter whichever direction it pointed.

We list xenon because refusing to would be its own kind of dishonesty. "The FDA has not approved it" is a fact about a regulatory process, not a fact about a molecule — and this directory exists partly because that distinction matters. The mainstream view on trans fats was fine for decades. Red 3 stayed legal in food until 2025, thirty-five years after it was banned in cosmetics. Being unapproved is not evidence of anything.

But the same scepticism has to point both ways. The strongest study for xenon has precisely the flaws we would call out in a pharmaceutical trial: no control group, an open label, retrospective registration, and authors who owned the company. If we would not accept that from Pfizer, we should not accept it here. And clinics claiming "no side effects" for a gas that renders people unconscious at 33% are not being persecuted by regulators — they are misrepresenting their own product.

What we think is true: xenon is pharmacologically real, structurally under-researched for reasons that have nothing to do with merit, and plausibly useful. What we do not know is whether it works for the things it is sold for, and there is currently no honest way to find out. Anyone pursuing it should treat it as a medical procedure, insist on anaesthetist-level supervision and oxygen monitoring, and be particularly careful with any clinic bundling it with detox under anaesthesia.