When 68-year-old Li Wei collapsed in his Beijing apartment, doctors rushed him to Beijing Tiantan Hospital, where he became one of 32 stroke patients enrolled in a groundbreaking trial that would lower his body temperature not with ice, but with two old drugs given together for the first time in this context: chlorpromazine and promethazine. For decades, inducing hypothermia has been seen as a potential way to protect the brain after stroke, but cooling patients safely and effectively has remained a challenge. Now, researchers from Capital Medical University have shown that this drug combination—dubbed C+P—can safely trigger a hibernation-like state in humans, reducing metabolic demand and potentially shielding the brain from further damage.
Stroke is a leading cause of death and disability worldwide. Even when blood flow is restored, the brain often continues to deteriorate in the hours that follow—a phenomenon known as reperfusion injury. Cooling the brain can slow this process, but traditional methods like ice packs or cooling blankets are imprecise and can cause shivering, which raises body temperature and counteracts the benefits. The idea behind C+P therapy is to mimic the natural torpor seen in hibernating animals, where metabolism slows dramatically without harmful side effects.
The journey to human trials began in mice. After inducing stroke-like conditions, researchers administered C+P and observed a drop in core body temperature to around 30–32°C, accompanied by a 40% reduction in oxygen consumption—a sign of slowed metabolism. Crucially, the animals didn’t shiver, and brain injury volume was reduced by up to 50% compared to controls. The same pattern held in rhesus monkeys: intravenous C+P lowered body temperature to 33–34°C, shifted metabolism from glucose to fat and ketones, and led to significantly smaller brain lesions.
In the Phase I clinical trial, 32 acute ischemic stroke patients received either 100 mg of C+P or a placebo within six hours of symptom onset. The treatment was well tolerated, with no serious adverse events linked to the drugs. Patients’ core temperatures dropped by an average of 1.5°C, and metabolic rate decreased—mirroring the animal findings. While the trial was not designed to measure long-term recovery, early neurological assessments suggested improved outcomes in the treated group.
Published in Science Translational Medicine, these results open a new frontier in neuroprotection. With millions of stroke survivors facing long rehabilitation journeys each year, a simple, drug-based method to buy time for the brain could transform care—especially in settings where advanced cooling equipment isn’t available. As research moves toward larger efficacy trials, the hope is that this hibernation-inspired therapy could become a standard part of stroke treatment, turning an ancient survival strategy into a modern medical breakthrough.