Those on American streets who fold their bodies!
You must have seen such weird images! A man collapsed without warning like a puppet with a broken line: his head drooped powerlessly, his waist bent like a spinal cord, his hands lolling softly on his sides, his face expressionless, his eyes hollow as if they were sucking away the light around him. He swayed so wriggling, both like a sleepwalker and like a zombie in a movie. Even standing, it gives you a sense of being asleep; He seemed to be slumped, as if he had been pulled by some invisible force, unable to take a step, and as if he were sinking into another unknown world.
 This is the famous " American fold , " also known as " fentanyl fold . "
As the deadliest drug in U.S. history, the fentanyl epidemic has become a social nightmare - someone dies every eight minutes from an overdose of fentanyl or its analogues, and "fentanyl folding" is its signature symptom. Why did this eerie gesture occur? Why is it called the "death of drugs"? Why is the fatality rate so alarmingly high? Today, we are looking at the biomedical aspects of a drug that can turn people into "folded zombies."
The original intention of fentanyl is not to harm people, but to relieve pain and save peopleă As a potent opioid analgesic , it was originally used in situations where rapid pain relief was urgently needed, such as in the last stages of cancer, surgical anesthesia, and battlefield rescueă Throughout history, the line between painkillers and drugs has often been blurred: many powerful painkillers were originally invented to relieve suffering, but have since become drugs of abuse.
The human struggle against pain has never stopped, and the quest for more powerful painkillers has never stopping. In the earliest days, people looked for medicine from nature: in the East, they used turmeric weed, and in the West, they made opium from poppies. In 1804, German pharmacists extracted morphine from opium and its pain-relieving effect was astonishing.
Decades later, British scientist Charles Wright synthesized heroin from morphine, which was then promoted as a "safer alternative." It wasn't until 1959, when Belgian pharmacologist Paul Janssen synthesized fentanyl, a new "painkiller in a second," that the arms race for analgesics went to the extreme - faster and smaller doses were needed, but more intensely.
Take intravenous injection: at the same dose, morphine takes 5-10 minutes to kick in, heroin takes only 2 minutes, and fentanyl takes only 30 seconds. In terms of pain relief, fentanyl is 30-50 times that of heroin, and 80-100 times that of the morphine. What's even more frightening is that just 2 milligrams of fentanyl - about the weight of a grain of salt - is enough to cause a cardiac arrest and death on the spot. It is this "second-acting, pain-relieving" property that leaves a permanent mark of pleasure on the brain once it is experienced, making it one of the most addictive drugs.
So why does fentanyl make pain evaporate? This begins with the human body's "pain-pleasure" mechanism. Our perception of pain and pleasure depends on a common system called the opioid receptor. This system of survival, which has evolved over thousands of years, is hidden in neurons, like a distributed "keyhole," responsible for regulating pain, emotional stress, and reward mechanisms. The "key" that can open these "keyholes" is opioids.
Fentanyl as the opioid drugs in the "ultimate form," is a synthetic product - neither heroin such a semi-synthetic products, nor morphine, papaverine and other natural extracts, but the ultimate product of laboratory synthesisă Under normal circumstances, when people are depressed or injured, the body will secrete trace amounts of natural opioid substances, such as endorphins , which bind to opioid receptors to block pain signals and stimulate the release of dopamine, making people feel relaxed and happyă This mechanism is the "self-comfort system" of the human body, but it has been completely hijacked by fentanyl.
Fentanyl's molecule is extremely fat soluble, and the human cell membranes and blood-brain barrier are also fat soluble - which allows it to enter the bloodstream as if it were uninhabited, and can penetrate the layers of barriers without impediment. In contrast, water-soluble morphine penetrates slowly, and semi-fat soluble cocaine has to travel in zigzags, and only fentanyl can "hit the dragon" and achieve "second effectiveness."
Once in the brain, fentanyl acts as a nerve lightning bolt that instantaneously hijacks the central system, especially the core areas that control motor posture and balance - the brain stem, the mycosis, and the spinal motor cortex. Within a few seconds, the person's reaction began to be slow, consciousness became blurred, hands and feet were not listening, and movements seemed to be slowed to 0.25 times the speed. The muscle tension is out of control, the body slowly leans forward, the back gradually arches, the waist slowly collapses, and the hands fall like dolls. The entire upper body looks like a heavy load attached to the body - this is why fentanyl folds: not a deliberate gesture, but a direct consequence of the central nervous system's "disconnection."
One might wonder why abusers always fold their upper body while their lower body supports their feet.
This is because the lower limbs of the human body have a basic system of reflexes of muscle tone, like "autopilot standing mode." Even when the central system fails, the muscles in the thighs, lower legs, and soles of the feet can still rely on spinal cord instincts to maintain standing. Just as a computer dies without losing power, even though the brain is "offline," the body can still rely on inertia and muscle memory to support it.
There are also those who feel that this exaggerated folding may cause a sprain, but this is not the case. This posture is not an active muscle bending, but a passive sagging of the muscle after the central "power out" - the muscle is completely relaxed, so it is not prone to traditional sports injuries. However, if this condition is maintained for a long time, the lower limbs will gradually lose strength, eventually causing the whole person to collapse or even become injured and comatose.
For first-time users with small doses, it usually takes 20 to 60 minutes to recover from the folding state; But the consequences for long-term abusers are far from a "temporary shift." Fentanyl repeatedly suppresses the central nervous system, leading to structural damage in related regions, ultimately making "folding" into difficult-to-correct muscle memory, and even causing irreversible permanent deformities.
However , folding is not the most fatal harm of fentanyl . Its suppression of the respiratory center is the real " hand of death . " Fentanyl's potency is so strong that, while blocking pain, it also suppresses the brain stem area that controls breathing - in simple terms, it makes people feel no pain and "forget" to breatheăWhat is even more frightening is that this kind of respiratory suppression is not a gradual process, but stops suddenly like turning off the light, leaving people no time to struggle and quietly die in a coma.
That's why fentanyl is called the silent killer. It has become the deadliest drug in the United States, killing between 80,000 people each year and accounting for more than 70% of drug overdose deaths. It is often mixed in a variety of illicit drugs, but in small doses it is incredibly lethal - even one inhalation could be the last breath. This is not alarmist, but a tragedy that is really playing out on the streets, in the bathroom, on the sofa every day.