A conducted electrical weapon sends rapid pulses of electricity through your body that hijack your motor neurons, causing nearly every skeletal muscle between the two electrode points to contract simultaneously and uncontrollably. For the duration of the shock, typically five seconds in a standard law-enforcement cycle, you lose voluntary control of your muscles and collapse. The experience is intensely painful, but the effects extend well beyond the sensation of pain itself, touching your breathing, blood chemistry, brain function, and sometimes causing serious secondary injuries when you hit the ground.
How the Electrical Pulses Override Your Muscles
The device works by delivering short, low-energy electrical pulses designed to stimulate motor neurons directly, producing what amounts to forced, involuntary muscle contraction across a wide area of the body. The pulses arrive at a frequency high enough to sustain continuous contraction rather than individual twitches. Modeling research has shown that at the standard pulse rate of around 19 pulses per second, the contractions produced reach roughly 46% of a muscle’s maximum force, which is enough to overwhelm whatever your voluntary nervous system is trying to do at the time.1PubMed. Theoretical comparisons of nerve and muscle activation by neuromuscular incapacitation devices Lower frequencies would not reliably override volitional motor control, which is why the devices are tuned to that range.
What this feels like from the inside is total loss of bodily control. Your legs give out, your arms lock or flail, and you go down. Once the current stops, recovery is remarkably fast. In a study that measured how quickly people could perform a simple button-press task after a standard five-second exposure, the average response time was about 1.3 seconds after the device shut off, and that was statistically no different from how fast they responded to a simple audio cue under normal conditions.2Forensic Science, Medicine and Pathology. Incapacitation recovery times from a conductive electrical weapon exposure Only two out of 32 subjects in that study managed to press the button during the exposure itself, and both had delays of three to five seconds. So the incapacitation is near-total while the current flows but lifts almost immediately once it stops.
What Happens to Your Breathing
One of the most alarming effects, both for the person being tased and for bystanders, is the impact on breathing. During the exposure, your chest wall muscles contract along with everything else, which sharply reduces how much air you can move. Research on law enforcement trainees found that both inspiratory and expiratory volumes dropped significantly during the shock, with the ability to breathe in affected more than the ability to breathe out.3PubMed Central. Respiratory and Cardiovascular Response during Electronic Control Device Exposure in Law Enforcement Trainees Many people describe feeling unable to breathe during the five-second cycle, and that description is physiologically accurate: your respiratory muscles are being electrically commandeered.
The reassuring part is what happens afterward. Once the current stops, a compensatory rebound kicks in. Breathing volumes actually overshoot baseline levels as your body catches up. A separate study measuring respiratory function in human volunteers found that at one minute after exposure, minute ventilation (the total volume of air moved per minute) jumped from a resting average of about 16 liters per minute to 29 liters per minute, and tidal volume increased from 0.9 liters to 1.4 liters per breath.4Annals of Emergency Medicine. Physiological Effects of a Conducted Electrical Weapon on Human Subjects Everything returned to baseline within ten minutes, and there was no oxygen deficit or dangerous carbon dioxide buildup detected at any point. So while the sensation of not being able to breathe is real and frightening, in a healthy person the respiratory system bounces back quickly.
Blood Chemistry and Metabolic Stress
Being tased is, metabolically speaking, a form of extreme involuntary exercise. All those muscles contracting at once burn through energy and produce waste products, particularly lactic acid. Animal studies using repeated exposures found that blood lactate levels spiked dramatically after the shock, with a slow return to normal that took over an hour. Blood pH dropped significantly as well, reflecting a state of metabolic acidosis, and took a similar amount of time to normalize.5Forensic Science International. Acidosis, lactate, electrolytes, muscle enzymes, and other factors in the blood of Sus scrofa following repeated TASER exposures Both the muscle contractions themselves and reduced breathing during the exposure contributed to the acid buildup.
A key question for real-world safety is what happens when someone is tased while already physically exhausted, since many people subjected to these devices in the field have been running, fighting, or struggling. A human study examined this scenario by having volunteers exercise to exhaustion and then receive a prolonged 15-second exposure. After exercise alone, the median blood pH dropped from 7.38 to 7.23 and lactate rose from about 1.7 to 8.4. Adding the taser exposure on top of that exhaustion nudged lactate up slightly further to about 9.9 but did not meaningfully worsen the acidosis already caused by the exercise itself.6PubMed. Prolonged TASER use on exhausted humans does not worsen markers of acidosis By 24 hours, all values had returned to normal. A companion study comparing continued exertion versus taser exposure after exhaustion found no difference in pH or lactate between the two groups at any point after the initial exercise, suggesting the device does not push the metabolic stress beyond what vigorous physical activity already produces.7Forensic Science International. Lactate and pH evaluation in exhausted humans with prolonged TASER X26 exposure or continued exertion
Muscle Damage
When muscles are forced to contract intensely, some muscle cells break down and release an enzyme called creatine kinase (CK) into the blood. Doctors use CK levels as a marker of muscle injury. Research into taser-related muscle damage found that exposures can produce modest CK elevations, but the picture is more nuanced than you might expect. The number of contact points (where the probes or electrodes touch) had a clear relationship with CK increases, while the duration of the exposure did not appear to matter much.8PubMed. The effect of an electronic control device on muscle injury as determined by creatine kinase enzyme In other words, being hit with more probe points or receiving multiple separate discharges produced more muscle damage than a single longer shock. Studies looking at simultaneous discharges from multiple devices confirmed this pattern, with CK increases at 24 hours that scaled with the number of simultaneous shocks received.9PubMed Central. The physiologic effects of multiple simultaneous electronic control device discharges
For most healthy people, these CK elevations are in the same range you would see after an unusually intense workout and resolve on their own. But in someone with underlying kidney problems or in cases of extreme or repeated exposure, the muscle breakdown could theoretically contribute to a condition where those breakdown products overwhelm the kidneys, a scenario that remains a concern in prolonged restraint situations even if it has not been directly attributed to a single standard-duration exposure.
The Cardiac Question
Whether being tased can stop your heart is probably the most debated aspect of these devices, and the evidence paints a reassuring but not entirely clean picture. Over 1.4 million documented human exposures, including training and field use, have occurred without credible evidence of the device directly triggering a dangerous heart rhythm.10PubMed Central. Physiology and pathology of TASER electronic control devices That is a strikingly large safety dataset by any standard.
However, animal research tells us that the possibility is not zero. In pig studies, when a taser dart landed close enough to the heart, the device’s current could directly trigger ventricular fibrillation, the chaotic rhythm that causes cardiac arrest. The critical dart-to-heart distance averaged about 17 millimeters for the first episode. Echocardiographic measurements of living humans show that the distance from skin to heart over the ventricle ranges from about 10 to 57 millimeters, meaning the dart-to-heart gap could be as small as 1 millimeter in a thin person hit in exactly the wrong spot.11PubMed. Taser dart-to-heart distance that causes ventricular fibrillation in pigs The researchers calculated the probability of a dart landing on the roughly one-square-centimeter zone over the ventricle and being close enough to cause fibrillation at about 1 in 5,800. That is low, but not negligible across millions of uses.
The practical takeaway is that the cardiac risk from a standard deployment in a person with a normal heart is extremely small, but it is not zero, and it may be higher in very thin individuals or in cases where one dart happens to embed directly over the heart.
Cognitive Effects After the Shock
The physical effects get most of the attention, but what happens to your brain after being tased matters too, especially in the context of law enforcement encounters where people are often questioned or asked to make legal decisions shortly after being shocked. A randomized controlled trial found that participants who received a taser exposure experienced meaningful drops in verbal learning and memory, and reported significant difficulty concentrating, along with increased anxiety and a feeling of being overwhelmed.12Applied Cognitive Psychology. Examining Cognitive Functioning Following TASER Exposure: A Randomized Controlled Trial These deficits lasted less than an hour for most participants but were substantial while they persisted.
A related study focused specifically on the kind of mental abilities needed to understand and waive legal rights, such as Miranda rights in the United States. The findings showed significant reductions in short-term auditory recall and the ability to take in new information through listening. Most subjects returned to their cognitive baseline within 60 minutes of the exposure.13Criminology & Public Policy. TASER Exposure and Cognitive Impairment: Implications for Valid Miranda Waivers and the Timing of Police Custodial Interrogations The researchers raised direct questions about whether legal waivers obtained within that first hour after a tasing could be considered truly informed, given the documented impairment. This is one of those areas where the science has clear policy implications that have not been fully absorbed by the institutions that use these devices.
Injuries From Falling
When you lose all neuromuscular control and fall, you fall the way an unconscious person would: without any protective reflexes. You do not put your hands out, you do not twist to absorb the impact, you just go down. The injuries that result can be far more serious than anything the electricity itself causes. A case series of taser-associated injuries documented a basilar skull fracture with brain hemorrhage requiring emergency surgery, a concussion with comminuted nasal and orbital floor fractures, and a case where a taser probe actually penetrated the outer layer of the skull.14PubMed. Taser and Taser associated injuries: a case series
The head injury problem is serious enough that researchers have tried to quantify it at scale. An analysis of fatalities across approximately three million field uses identified 16 probable cases of fatal brain injuries caused by falls following an electrical weapon deployment, giving a risk of roughly five per million uses.15PubMed. Fatal traumatic brain injury with electrical weapon falls That rate is small in absolute terms, but the same study noted it was higher than the theoretical risk of the electrical current itself causing death. In other words, the fall may be more dangerous than the shock, particularly when the person is standing on a hard surface, at height, or near obstacles.
Eye Injuries From Probes
The barbed metal probes fired by taser-type devices travel at significant speed and are designed to embed in skin or clothing. When one of those probes hits an eye, the results are devastating. A comprehensive review identified 28 cases of penetrating eye injury out of about 3.4 million field uses, giving a risk of roughly 1 in 123,000 deployments.16PubMed. Eye injuries from electrical weapon probes: Incidents, prevalence, and legal implications Of those 28 cases, 18 resulted in total loss of vision in the affected eye or required surgical removal of the eye entirely. At least one case involved a probe that impaled the orbit deeply enough to require primary enucleation, meaning the eye was removed during the initial surgery because the damage was beyond repair.17PubMed. Impaled Orbital TASER Probe Injury Requiring Primary Enucleation
These injuries are rare but essentially untreatable when they occur. They represent a risk that is entirely distinct from the electrical effects of the device and arise purely from the ballistic impact of the probes. The face and eyes are not targeted intentionally, but in a dynamic encounter, probes can land anywhere on the upper body.
People With Implanted Heart Devices
A reasonable concern is what happens if a person with a pacemaker or implantable defibrillator gets tased. A bench study using a taser-type device applied to implanted pacemakers and defibrillators found that the electrical pulses were detected by the implanted defibrillators as a rapid heart rhythm, but because the five-second exposure ended before the device could fully charge and deliver a shock, the detection was aborted and no inappropriate therapy was delivered. Pacemaker and defibrillator lead measurements were unchanged before and after the exposure, and no device malfunctions occurred.18PubMed. Do electrical stun guns (TASER-X26) affect the functional integrity of implantable pacemakers and defibrillators?
A more recent study testing several different handheld electrical weapons found a more varied picture. Some devices caused temporary inhibition of pacemaker stimulation in up to 100% of tested units and triggered stored high-rate episodes in up to 60% of defibrillators, depending on the specific weapon model used. Importantly, no permanent damage to any device was detected.19Heart Rhythm. Effects of handheld electro-shockers on cardiac implantable electronic devices The temporary pacing inhibition is the real concern: if someone is fully dependent on their pacemaker for every heartbeat, even a few seconds without pacing could cause a dangerous drop in cardiac output. The risk varies substantially depending on the specific weapon and the specific implanted device, which makes it difficult to give a single clear answer about safety for this population.
Cocaine and Other Stimulants
Many in-custody deaths following taser use have involved individuals under the influence of stimulants, which has fueled speculation that drugs like cocaine make the heart more vulnerable to the device’s electrical pulses. The animal evidence actually runs in the opposite direction. A study in pigs found that cocaine infusion raised the threshold for taser-induced ventricular fibrillation by 1.5 to 2 times at every electrode position tested, meaning the heart was harder, not easier, to push into a lethal rhythm after cocaine exposure.20PubMed. Effects of cocaine intoxication on the threshold for stun gun induction of ventricular fibrillation This does not mean stimulant intoxication is safe during a taser encounter; people on stimulants are often in a state of extreme physiological stress, with elevated heart rate, high body temperature, and dehydration, all of which create independent cardiac risk. But the electrical threshold data suggests the device’s pulses are not synergizing with cocaine to make fibrillation more likely.
The deaths in these cases are more plausibly related to the broader crisis of physiological collapse in an agitated, overheated, exhausted person rather than a specific electrical-cardiac interaction amplified by the drug. Research on encounters involving signs of extreme agitation found that when a conducted electrical weapon was applied, no arrestees died in any of the 240 incidents studied, and about four out of five sustained no injury.21Forensic Research & Criminology International Journal. Assessing the symptoms associated with excited delirium syndrome and the use of conducted energy weapons That said, the broader context of these encounters, including prolonged restraint, prone positioning, and sustained physical struggle, introduces risks that go well beyond the taser itself.
Skin and Probe Wounds
The probes leave small puncture wounds at the entry sites, typically a few millimeters across. In dart-mode deployments where the probes embed in the skin, removal can cause minor tearing, and the wounds occasionally become infected if not properly cleaned. In drive-stun mode, where the device is pressed directly against the body without firing probes, the electrical arc can leave superficial burns at the contact points. These are generally first-degree or shallow second-degree burns that heal without scarring in most cases, though the marks can persist as small, paired, discolored dots for weeks or months. The skin injuries themselves are rarely medically significant, but they are among the most visible reminders of the experience and are often documented in forensic examinations.
How Long the Full Recovery Takes
Motor control returns within seconds, as the incapacitation recovery data shows. Breathing normalizes within ten minutes. The cognitive fog lifts within an hour for most people. Blood chemistry takes longer: lactate and pH typically return to baseline within a few hours in a healthy person, though animal data suggests the process can stretch beyond an hour after heavy or repeated exposures.5Forensic Science International. Acidosis, lactate, electrolytes, muscle enzymes, and other factors in the blood of Sus scrofa following repeated TASER exposures Muscle soreness, similar to what you would feel after an extremely intense workout, can last a day or two, and the CK elevations reflecting muscle cell breakdown peak around 24 hours before resolving. The probe puncture wounds take a week or so to heal fully.
The experience most people describe, looking back, is not one of lasting physical injury but of overwhelming, disorienting intensity. The combination of total loss of bodily control, pain, inability to breathe, and the sudden fall creates a psychological impact that can exceed the purely physical one. That is by design: the devices are intended to achieve compliance through temporary incapacitation, and for the vast majority of exposures, the temporary part holds up. The exceptions, while rare, tend to involve secondary trauma from falls, probe injuries to vulnerable anatomy, or the compounding effects of pre-existing medical conditions and extreme physiological stress.