“Friends” star Matthew Perry repeatedly injected ketamine before his death, and the recent chatter surrounding tech billionaire Elon Musk’s ketamine use has rekindled debate. The substance, available for decades, has in recent years surged in popularity not only among celebrities but also within club scenes and segments of the gay community. A Berlin study, according to Felix Betzler of Charité in Berlin, found that ketamine was already the fourth most-used club drug six years ago. “Since then, ketamine has gained additional traction,” Betzler notes.
Several factors contributed to its rise: easy availability, comparatively low price, and the immediate effects it produces. Ketamine’s profile in pop culture also reinforces its appeal. It’s been referenced in music and media, with Placebo’s “Special K,” The Polish Ambassador’s “Space Kitten,” and Kissy Sell Out’s “Get Ready for the K-Hole!” among the examples that keep the drug in the public eye.
Then there is the celebrity factor. Musk has said that ketamine helps him climb out of dark mental places. In a 2024 interview, he disclosed that he uses a very small amount about every two weeks. After a critical media report, he recently stated that he has not used the substance since then.
In fact, ketamine is being studied in numerous clinical trials for its effectiveness in treating depression. A ketamine-derived drug called esketamine has already been approved in both the EU and the United States for emergency treatment of treatment-resistant depression when administered under medical supervision as a nasal spray. That the substance is viewed as a medication—and thus as safe—appears to be another driver of its rising popularity, Betzler says.
Where does ketamine come from?
The active ingredient is synthesized in the lab. It first appeared in 1962 in the United States during research for a new anesthetic. Ketamine was tested on American soldiers in Vietnam and later became established in both human and veterinary medicine. Because of side effects like hallucinations and near-death experiences, it is now rarely used as an anesthetic; instead, emergency responders use it as a painkiller.
As a recreational drug, ketamine has also been used for decades. The substance, often called “Special K” or simply “K,” is typically snorted as a white powder, Betzler explains. The effects last about one to two hours. Because it reduces pain, ketamine is also sought by some people who engage in certain sexual practices.
What effects do users hope to experience?
As a party drug, ketamine is used for its euphoric and dissociative effects. Perception of the surrounding environment—colors, sounds—can change dramatically as the dose rises. In clinical terms, a user may feel a detachment from their body or a sense of ego dissolution, sometimes called a “K-hole” in its strongest manifestation. Viewers often interpret this state as unconsciousness.
Do users see ketamine as less harmful than it is?
In many cases, yes—according to experts. The familiarity of ketamine’s medical use is a key reason. “Whenever a substance is used therapeutically as well, it can dull the awareness of its risks,” Betzler says. Schäfer also believes there’s a danger of normalization due to therapeutic use: “There’s a risk of downplaying the dangers because some people think of it as medicine.”
In a British study, a large portion of users with what researchers call a ketamine-use disorder reported that they only realized the danger when their use had already spiraled out of control. Many indicated that the therapeutic exploration of the drug might have masked its potential for abuse, as noted in the journal Addiction.
How strong is the addiction potential?
The most common pattern is using ketamine occasionally in leisure settings or at parties, Schäfer, director of the Hamburg Center for Interdisciplinary Addiction Research (ZIS) at the University of Hamburg, says. Unlike heroin or fentanyl, there is no clear physical dependence on ketamine. Psychologically, however, the craving can be intense—driven by a desire to escape from burdensome feelings. “Often it’s about escaping painful emotions.”
Because the drug is also used in supportive therapies, many people turn to it as a form of self-medication for mental health issues, Betzler notes. “It’s creeping into everyday life, reducing anxiety in some cases. That can lay the groundwork for dependence.” Schäfer adds that those who want to explore ketamine therapeutically should seek professional counseling rather than experimenting on their own. “Self-experimentation with psychedelics is never a good idea.”
What are the consequences of ketamine use?
Ketamine dependence is linked to a high burden of physical health problems and psychological consequences, according to a study by Celia Morgan and colleagues from the University of Exeter, published in Addiction. The study involved 274 people, who on average used two grams of ketamine per day.
Sixty percent reported bladder or nasal issues, and a similar share experienced abdominal cramps—pain that often drove them to redouble their drug use to alleviate the discomfort. A hallmark of prolonged ketamine misuse is the so-called ketamine bladder, which damages the lining of the bladder, leading to incontinence and, in extreme cases, removal of the bladder with urine collected in bags.
A ketamine bladder can develop after only a few weeks of heavy use, Betzler warns. In the long term, substantial cognitive impairments—such as problems with concentration and memory—are possible, and in people predisposed, depressive symptoms may worsen or psychosis may be triggered, Schäfer adds.
Ketamine use can lead to respiratory arrest
Under the influence, ketamine can trigger more impulsive behavior. Judgment and self-control diminish, and risk-taking escalates, which can result in aggressive confrontations or accidents. When ketamine is used in combination with other drugs, there is a real danger that the drug will depress the respiratory center, causing life-threatening breathing problems or loss of consciousness.
The acute danger can also come from temporary immobility. “You can be largely unable to move for up to six hours,” Schäfer explains. The combination of a hot tub and ketamine use is not a good one: the late Friends character’s storyline is often cited because of the high ketamine concentrations found in Matthew Perry’s blood when he died alone in a hot tub in October 2023.
“Ketamine is not a harmless drug,” Schäfer emphasizes. “Even long-term use for recreational purposes is extremely risky.” The risk is even greater for young people, whose brains are still maturing.
More education is needed — also because the number of young users appears to be rising, Betzler observes. He notes that ketamine users used to skew toward people in their mid-20s; today, it’s more common at younger ages. There are no robust, up-to-date statistics on this yet. (cw/dpa)
