Ketamine: What You Need to Know to Reduce Risks

December 10, 2025

Ketamine circulates widely, often without clear information about its effects or its dangers. Without alarmism or stigma, health professionals warn about the dangers linked to repeated use and remind of the importance of risk reduction.

“Special K”, “K”, “ketamine”: from free parties to chemsex plans, the diverted use of ketamine has spread widely in recent years. According to the French Observatory for Drugs and Drug Addiction Trends, nearly 3% of adults in France have already tried this powerful anesthetic sought for its euphoric effects. Now accessible and very present in festive circles, this drug raises concerns among health professionals because repeated use can cause severe, sometimes irreversible damage. The importance of having good information to reduce the risks of its use.

Used since the 1960s as an anesthetic medication, notably in veterinary medicine and human anesthesia, ketamine gradually entered the so-called “recreational” uses. Outside a medical setting, it is valued for its expected disinhibition effects that accompany altered bodily perceptions, dissociation, and the attenuation of pain – properties that make it common in chemsex contexts, particularly during “hard” practices.

K-holes and sequelae

But just because it is used in medicine does not mean recreational use is without danger. In the short term, ketamine exposes users to several risks: bad trips with anxiety crises, hallucinations, and delirious bursts; in cases of a large dose and/or combination with alcohol, it can provoke a “K-hole,” characterized by a total loss of orientation, inability to speak or move, intense and distressing hallucinations. This type of experience can lead to memory loss, cognitive or mood disturbances, which may take several days to dissipate. It is also necessary to consider injuries and accidents related to its anesthetic effects – because one may not feel the signal of pain, one is more likely to hurt oneself. We also recall the death of drag queen The Vivienne following a cardiac arrest linked to her ketamine consumption.

As for the idea that ketamine would not cause addiction, Dr. Joëlle Micallef, from the CEIP-A (Center for Evaluation and Information on Pharmacodependence and Addiction Vigilance) Paca-Corse and AP-HM (Assistance publique – Hôpitaux de Marseille), challenges it: “There is of course a risk of dependence, with the need to progressively increase doses and an irresistible urge to consume.” Like the National Agency for the Safety of Medicines and Health Products, which published this summer a statement on the proper use of ketamine, she also warns against a side effect as little known as it is serious, and on the rise: urinary and renal damage. “Ketamine destroys the bladder. We have had cases of extremely severe damage where the bladder size is reduced by ten, which is extremely disabling”, she explains. In the most severe cases, the bladder may need to be removed and rebuilt with a segment of intestine. “Seeing this in 25-year-old users is dramatic”, laments the specialist. In addition to these lesions, there are sometimes acute abdominal pains, which further fuel the addiction cycle – some use to ease the pain – as well as liver damage.

As with any drug use, risk-reduction practices are therefore essential. “Avoid using alone and avoid mixing substances. It is also essential to monitor doses because, unlike opioids, there is no antidote to ketamine overdoses, and finally ensure the composition and purity of what one consumes”, enumerates Joëlle Micallef, stressing the importance of testing her products. When use becomes daily and solitary, it is crucial to have access to compassionate and non-stigmatizing help, whether it comes from peer groups (forums psychoactif.org or psychonaut.fr), community associations (Chempause, chemsex listening and support services from AIDES) or addiction professionals (Checkpoints, CAARUD, CSAPA).

prevention | health | drugs | chemsex
Sophie Brennan

Sophie Brennan

I’m Sophie Brennan, an Australian journalist passionate about LGBTQ+ storytelling and community reporting. I write to amplify the voices and experiences that often go unheard, blending empathy with a sharp eye for social issues. Through my work at Yarns Heal, I hope to spark conversations that bring us closer and help our community feel truly seen.