Horse tranquilizer? Bryan Johnson’s Attempt to Tarnish Ketamine
Bryan Johnson, a leading figure in the field of biohacking, recently experimented with ketamine, and dismissed it as a mere “horse tranquilizer.” His in-depth experience with ketamine should have given him a profound understanding of its potential beyond putting down animals.
Johnson, a biohacker and founder of a neuro-gauging device called the Kernel, shared insights on X about his experiments with ketamine in a series of posts dated February 18, 2025. He detailed a 15-day experiment where he injected ketamine and tracked his brain activity using Kernel Flow. He noted that his brain’s ‘functional connectivity’ remained stable for five days before the injection, underwent significant changes during the ketamine session, and then saw a decrease in ‘connectivity’ post-session, gradually returning to baseline after three days. Johnson described this as ‘scrambling’ his brain’s predictable patterns, likening it to rerouting plane traffic from larger airports to smaller ones, suggesting potential for new neural connections. He framed this as a ‘world’s-first study’ answering what happens to the brain before, during, and after ketamine treatment, highlighting a therapeutic window that closes as patterns re-emerge.
Johnson is a bio-hacker, a devout vegan, a man of extraordinary wealth, and probably a decent human being, and surely a very nice person; but one thing he is not, is a researcher.
He’s obsessed with not getting older, spending millions to defy his age. He’s like Asprey, Greenfield, Sinclair, and Parrish – all longevity chasers terrified of their own mortality. They’re afraid of what uniquely makes us human: that we all are going to face death. Aging’s not a problem to solve; it’s the deal we signed up for. I almost pity them—every sunrise drags them closer to the inevitable.
What people like Johnson can’t wrap their minds around is that even with all the cutting-edge tricks—fasting, supplements, cold plunges, whatever—the body’s life force still slips away over time. It’s like trying to hold water in your hands; you can slow the drip, but eventually, it seeps through. Biohackers might stretch the timeline and optimize the machine, but age isn’t just a number—it’s a slow unwind of energy that no protocol can fully rewind. Still, there’s something gutsy about trying. One day, every one of them will look like Jimmy Carter did just short of his 100th birthday, his gaping mouth displaying the ‘O-sign’: a shell of a human vividly devoid of life.
So why’s Johnson zeroing in on ketamine for his latest stunt? Why not other psychedelics like psilocybin or ayahuasca? This choice remains a mystery. All the references about how different psychedelics are in my book, The Revolutionary Ketamine.
Ketamine’s Numerous Favorable Properties
Johnson’s post misses the mark and doesn’t help the problem he thinks ketamine’s creating by calling it a horse tranquilizer. Decades of research on PubMed and 70,000 articles shows how ketamine affects the brain, particularly its rapid antidepressant effects, neuroplasticity, potential downsides, but most importantly, it’s safety when used appropriately.
Ketamine was discovered in 1962 by Parke-Davis (now Pfizer Inc.) during research into the psychotropic and anesthetic effects of phencyclidine (PCP). Ketamine, identified as a PCP derivative with short-acting anesthetic effects and a strong safety profile, gained Food and Drug Administration (FDA) approval in 1970. It has been listed on the WHO List of Essential Medicines as an anesthetic since 1984 when it was first added. This isn’t fringe, it’s foundational.
Burn Victims
First, ketamine is an anesthetic that helps millions of people get through difficult times. Just think about the thousands of people and animals with severe burns. Ketamine is the drug that gets them through the excruciating pain of dressing changes. Those experiences are not something you’d wish on anybody.
Ketamine is a Drug that Saves Lives
Why? I’ve used it many times to pull back patients from the edge of suicide. I’ve written about this in my Substack and book, The Revolutionary Ketamine. We have no other medication that rapidly reverses suicidal ideations like ketamine. For the millions of us touched closely by suicide, like me, like Gavin de Becker, the potential of ketamine can be life-saving, and it’s staggeringly effective when paired with psychotherapy. This potential gives us hope for the future of mental health treatment.
So when Bryan Johnson dismisses ketamine as a “horse tranquilizer,” it’s not just clueless—it’s a slap in the face to a drug that’s anything but trivial. His post shows a lack of understanding and respect for this medication. It resembles the same tunnel vision that drives him to take hundreds of daily supplements in his quest to evade death. It’s crucial that we, as a community, seek and promote accurate information about ketamine, rather than being swayed by misleading claims.
Ketamine, an NMDA receptor antagonist, is well-known in anesthesia for providing dose-dependent anesthetic, sedative, and analgesic effects.
Ketamine has gained popularity as an anesthetic agent owing to its favorable cardiovascular effects in hemodynamically compromised patients. However, ketamine also has more diverse effects, including bronchodilation in asthma, anti-inflammatory effects in sepsis, neuroprotective properties in brain trauma, tumor inhibition in cancer, prolonged antidepressant effects, and finally, its ability to stop suicide.
Military and Ketamine
Its hospital, military, and disaster medicine are well documented throughout Iraq and Afghanistan. Many services use ketamine for both sedation and anesthesia in a pre-hospital context owing to its beneficial effects, wide safety margin, multiple routes of administration, and ease of storage and transport. In addition, it has become a preferred anesthetic in resource-limited environments.
In 2002, Bonanno reported that ketamine with a benzodiazepine provided safe and effective general anesthesia during the civil war in Somalia. Following this, an Australian medical team reported using ketamine anesthetics to perform 120 surgical procedures in austere conditions following the Boxing Day tsunami in Indonesia in 2004. Mulvey and colleagues also published their experiences of using ketamine to facilitate emergency surgery for victims of the 2005 Kashmir earthquake. Both reported ketamine as safe and effective in a resource-constrained environment, with a low incidence of reported significant adverse events.
More recently, the pre-hospital use of ketamine received global attention after 13 people, 12 of whom were children, were rescued from a flooded cave system in Thailand in 2018. The rescuer, an Australian anesthetic consultant and cave diving expert, successfully used ketamine to provide anesthesia to the individuals whilst avoiding the need for tracheal intubation and avoiding hemodynamic or respiratory compromise.
For example, in 2004, Porter published a case series of 32 pre-hospital adult and pediatric trauma patients treated by the British Association of Immediate Care Scheme (BASICS). Porter described ketamine as safe and effective for analgesia and anesthesia in a mixed cohort of pre-hospital trauma patients, with no significant adverse airway effects and maintained blood pressure in patients with hypotension.
Other European countries have also adopted the pre-hospital use of ketamine; in a 2020 survey of members of a Swiss-based alpine helicopter rescue service, 100% of respondents reported ketamine to be safe and useful, and 62% even described ketamine as “irreplaceable.”
Brain Connectivity and Johnson’s Research Stunt
A closer look at how Johnson tosses around words – horse tranquilizer, functional connectivity, and scrambling. This whole stunt is a sales pitch for his device called the Kernel. It’s labeled as a neuroimaging device. Devices that measure brain activity and electrical activity are blunt tools at best. Even the best brain researchers are honest in that short of doing fMRI, we’ve not a clue what’s going on in the brain. Johnson claims he’s the first one to get ketamine and measure brain activity. Not true. Good research has already shown that ketamine affects many brain structures like the hippocampus, the prefrontal cortex, amygdala, cingulate cortex, the brainstem, and more. It’s the rigorous research and professional expertise that we should rely on for accurate information.
Consciousness and awareness? That’s the razor’s edge of adaptation. Awareness cannot be explained, especially with the Kernel. The brain’s complex and everything in the brain happens unconsciously, and we do not have any access to it. No gizmo can explain that.
Johnson’s use of Kernel Flow to track brain changes during his ketamine experiment revealed a disruption in his brain’s ‘functional connectivity.’ This disruption, which peaked during the session and gradually returned to baseline over three days, suggests a temporary ‘therapeutic window.’
It’s difficult to even know what he means by ‘functional connectivity.’ Connectivity – is a word that assumes a connection. The brain receptors function within a complex dance and depend on the context. Calling it connectivity is childish at best. Of course, we can see more active parts of the brain, and we automatically assume this represents connectivity. But in reality, we don’t know. All one has to do is examine the picture of neurons to know that we have no idea what or how our brains connect.
The process is so complex that we don’t even know what is happening inside the brain, especially when it comes to psychedelics. The main point about psychedelics is that they allow more sensory information than usual, thus increasing brain activity and entropy.
“Functional” refers to how a system operates. The brain, like the heart, functions constantly without us ever knowing. We don’t even know where brain function comes from. Is information truly in our brains? There are many examples of knowledge that may be out there somewhere in the cosmic ether and not in our brains.
EEG, infrared, and fMRI are blunt instruments, like trying to read a novel with a sledgehammer. The point is that we are all using blunt instruments in an attempt to understand what’s going on in the brain. A great example that is mind blowing is decorticated cat studies—where the cerebral cortex is surgically removed—offers a window into how much locomotion is wired into lower brain structures like the brainstem and spinal cord. These experiments, mostly from the mid-20th century onward, show that even without the cortex, cats can still move in ways that look like walking. It’s not perfect, but it’s rhythmic and coordinated enough to suggest the brain’s upper layers aren’t the whole story.
Underwent significant changes?
Again, what does this even mean? Changes in brain electrical activity that is barely measurable in the first place? To measure a change in something, we have to know what we are measuring and where we start from. Even using very high-level EEGs doesn’t give us this information.
Ketamine’s chaos isn’t random—it’s a cascade. NMDA receptor blockade spikes glutamate, ripples through AMPA receptors, and tweaks dopamine, serotonin, and opioid systems. Structures like the PFC and hippocampus get a plasticity boost; amygdala and Anterior Cingulate Cortex dial down distress; thalamus fades the sensory feed.
The Gap Between Well-Trained and Untrained Athletes
Take, Dr. David Eagleman, a Stanford-based neuroscientist (not a biohacker) who was recently on the Jordan Peterson Podcast. He’s known for his work on brain plasticity and time perception and conducted a fascinating EEG study with cup stackers to explore how expertise shapes brain activity. This wasn’t a formal PubMed-published experiment, but a demonstration tied to his PBS series The Brain with David Eagleman (Episode 3, aired October 2015). He teamed up with Austin Naber, a world-record-holding cup stacker who was 10 at the time, to compare their brain responses during the task.
They used EEG helmets to measure brain electrical activity. Eagleman, a novice, stacked cups alongside Naber, a pro who’d practiced 3-4 hours daily. The results were striking. Eagleman’s EEG showed a storm of beta-wave activity (13-30 Hz) tied to active problem-solving and effort. His brain worked overtime trying to figure out rules and coordination. Naber’s EEG, in contrast, was quiet—minimal beta spikes despite his lightning-fast stacking (he could finish a cycle in under 5 seconds). His brain barely flinched, suggesting the task was automatic, handled by unconscious circuits honed through repetition.
Eagleman’s takeaway was about efficiency: beginners burn energy wrestling with conscious control, while experts offload to the non-conscious brain, freeing up resources. It’s not that Naber’s brain was less active overall—subtler alpha (8-13 Hz) or theta (4-7 Hz) waves might’ve been at play, reflecting a relaxed, flow-like state—but the EEG highlighted how expertise dials down the noisy effort signals. This aligns with broader neuroscience: practice shifts tasks from the prefrontal cortex (deliberate thought) to the basal ganglia and cerebellum (automated action). It might have something to do with glutamate efficacy in the brain and less entropy in the system.
Similarly, we would expect well-trained athletes with very good VO2 maxes versus untrained athletes to have a quieter and possibly more accurate EEG representation at VO2 max. This is my current PhD thesis at the University of Paris with Dr. Veronique Billat.
Conclusion
I’m glad that Bryan Johnson is dabbling with ketamine. One day, when the biohacking dream fades and when he learns that the date of his death certificate is likely fixed and not decided by him, at least he’ll know that ketamine might help him through these difficult times as it has thousands of others. On the other hand, it’s great that people like Johnson are improving their health and, hopefully, will decrease their disability-free days in life.
Perhaps Johnson should try another experiment. Using his Kernal device, he could dose himself with ketamine, jump inside a hyperbaric oxygen chamber, with red lights intact, and measure what happens. That would be interesting.
Refs
https://news.harvard.edu/gazette/story/2023/05/how-ketamine-affects-three-key-regions-of-brain/
https://www.frontiersin.org/journals/neuroanatomy/articles/10.3389/fnana.2022.795231/full
https://news.mit.edu/2024/study-models-how-ketamines-molecular-action-leads-to-brain-effects-0604
https://news.columbia.edu/news/new-study-maps-ketamines-effects-brain
https://pmc.ncbi.nlm.nih.gov/articles/PMC8972190/
https://pmc.ncbi.nlm.nih.gov/articles/PMC6612456/
https://news.yale.edu/2024/04/17/ketamine-produces-wide-variety-responses-brain-researchers-find
https://theherstonproject.com/2022/02/the-brain-summary/
The fact that BJ is a Vegan makes the study a lame duck for me overall unfortunately. There’s No substitute for animal Fat especially where the brain is concerned, and I lack respect for him as a biohacker because of this blind spot. Ketamine is a powerful tool on so many levels. To put Ketamine in a small mental box like this is immature at best and is irresponsible & irrelevant. Plus in all honesty he looks a bit like a ghoul lacking in vitality might be a nice guy, but he doesn’t radiate light and I’ve seen his list of protocols and it’s definitely lacking in my opinion.
Thanks Johnathan. Johnson is another example of "The Human Condition" of Hubris. The miracle of life and cycle of life are within us all and while we can slow the aging process to a crawl we eventually hit a point of inflection or a point of inflection where an acute condition/disease runs amuck. Labelling Ketamine as a Horse Tranquilizer only demonstrates this hubris and ignorance rather than as a wonderful tool in capable hands and the appropriate situation.