In 2011, Radboud University Medical Centre finally agreed to test him. They injected him with a bacterial toxin that normally triggers a strong immune response. The fever never came. Since then the method has been examined in more than twenty peer-reviewed studies — some landmark, some null, all here.
One man, one injection of E. coli endotoxin, and a monitor. His adrenaline rose; his immune response was less than half of what controls had shown. The question that mattered was not whether Wim was special. It was whether he could teach it.
Twenty-four healthy men. Twelve trained for ten days in meditation, breathing and cold. All injected with endotoxin. The trained group raised epinephrine, boosted the anti-inflammatory cytokine IL-10, suppressed TNF-α, IL-6 and IL-8, and felt almost nothing.
A Radboud UMC study later separated the ingredients: the breathing technique was the active component. Cold exposure alone did not significantly reduce inflammation.
One subject.
Twelve trained volunteers.
Wayne State imaging.
Spondyloarthritis trial.
No cardiovascular benefit in fifteen days.
Promising signal, low quality.
Rumination reduced.
Four hundred and four participants.
Cytokines reduced in sixty patients.
The 2014 study is a genuine landmark: voluntary influence over the autonomic and innate immune systems. But most studies are small; several are null; expectancy effects are real; and long-term clinical claims — curing MS, cancer — far exceed the evidence. This platform grades every study and never makes a claim the library cannot support.
Every study with its DOI, its question, its method, its finding and its limits.
Could one man voluntarily influence his autonomic nervous system and immune response?
Strong signalPNAS 111(20):7379–7384 · 2014Can healthy volunteers learn to do what Wim did?
Strong signalPLOS ONE · 2014Is brown fat the secret of Wim's cold tolerance?
Early evidenceReport · 2014Does the breathing prevent altitude sickness?
Early evidenceClinical Rheumatology 35:1081–1085 · 2015Does what you expect change what your body does?
PromisingNeuroImage 172:632–641 · 2018What does Wim's brain do in the cold?
PromisingEvery new Wim Hof Method study summarized within forty-eight hours of publication. For the evidence-hungry.
Check your inbox — it is on its way. Welcome to the cold.
The research agenda, pre-registration doctrine, data partnership principles and the institutions to date.