"Proto": Cases of poisoning continue to rise
Since 2020, reports of poisoning linked to the misuse of nitrous oxide, or “nitrous,” have been steadily increasing. This so-called “laughing gas” can lead to addiction as well as severe, sometimes irreversible, complications affecting the nervous system and the cardiovascular system (heart and blood vessels) when taken repeatedly and/or in large quantities.
Illegal drugs
thematic dossier
The use of illicit drugs exposes individuals to various health, social, and legal risks. In light of this major public health issue, prevention is essential.
Nitrous oxide is primarily used by adolescents and young adults: according to data from the Santé publique France Barometer, in 2022, 14% of 18- to 24-year-olds had already tried it, and more than 3% reported having used it during the year. Not all of these young users are aware of its dangers. In response to this public health challenge, the ANSM, ANSES, and Santé publique France are reiterating preventive measures and guidelines for managing harm associated with nitrous oxide use.
Between 2019 and 2020, ANSES identified a concerning increase in poisonings linked to the misuse of nitrous oxide cartridges among young people. These data contributed to the 2021 law on the prevention of dangerous uses of nitrous oxide.
Since 2013, the ANSM has been monitoring this non-medical misuse of nitrous oxide through an addiction surveillance survey. Conducted by the Centers for Evaluation and Information on Drug Dependence and Addiction Surveillance (CEIP-A), this survey is supplemented by an analysis of data from poison control and toxicovigilance centers (CAP-TV).
In 2023, 472 reports related to nitrous oxide use were recorded by the CEIP-A, representing a 30% increase compared to 2022. The CAP-TVs received 305 reports, a 20% increase from 2022. These figures confirm the rise in the number of reported cases of complications associated with nitrous oxide observed in recent years. We note that the proportion of reports involving women is increasing.
These reports also show an increase in cases linked to repeated and prolonged (more than one year) use of nitrous oxide. Among these reports of abuse, misuse, and dependence, 92% involve the consumption of high doses and the use of large-volume cylinders. 50% of them report daily consumption.
Cases of abuse, misuse, and dependence are rarely associated with the use of other substances.
On March 16, 2023, the European Chemicals Agency (ECHA) classified this substance as toxic to reproduction, Category 1B, following a proposal by ANSES, marking the first step toward European-level regulation.
In 2023, for the first time, the CEIP-A and CAPTV received reports of two newborns presenting with neurological disorders at birth in the context of the mother’s repeated misuse of nitrous oxide during pregnancy. We particularly warn pregnant women and women of childbearing age about the potentially serious risks to the unborn child from significant exposure to nitrous oxide during pregnancy.
Nitrous Oxide: Key Figures for 2023
The number of reports tripled between 2020 and 2023
The number of serious addiction-related cases increased 3.8-fold between 2020 and 2023
In 2023, 10% of these reports involved minors
More than 80% of reports involved neurological disorders
Addiction treatment is offered in only 16% of cases, with patients refusing treatment in 15% of cases
59% of reports involved repeated use over a period of more than one year
Health Risks
When nitrous oxide is used repeatedly, at frequent intervals, and/or in high doses, it can lead to serious complications, as confirmed by the latest data from the CEIP-A and CAP-TV networks:
Use disorders (loss of control over consumption), including cases of dependence;
Neurological complications: sensory and/or motor disorders with numbness, muscle weakness, or even loss of the ability to walk. Severe nerve pain, coordination problems, and urinary disorders (difficulty controlling the bladder or even urinary incontinence) may also occur;
cardiovascular problems (heart and blood vessels): formation of blood clots (thrombosis), which can lead to death in the event of a pulmonary embolism;
psychiatric symptoms: hallucinations, episodes of delirium, mood disorders.
Nitrous oxide alters sensations and impairs reflexes. Driving a vehicle after using it—whether a car, bicycle, or even a scooter—can cause serious or even fatal accidents.
Vitamin B12 as an “antidote” to nitrous oxide: a false solution
Taking vitamin B12 supplements is not enough to counteract the harmful effects of nitrous oxide. If you continue to use nitrous oxide, the vitamin B12 will be systematically neutralized and rendered ineffective.
To protect your health, the best solution is to avoid using nitrous oxide.
Support options are available.
Information and support for people who use “nitrous oxide” and their loved ones
What to do in case of nitrous oxide poisoning?
Nitrous oxide poses numerous health risks. If, after using it, you experience numbness in your arms and legs, a burning sensation or electric shock-like feeling, tingling, loss of sensation, or difficulty walking or moving, consult a healthcare professional or contact your poison control center (01 45 42 59 59).
If you or someone around you feels unwell, has difficulty breathing, or is experiencing impaired consciousness, call an emergency number immediately (medical emergency at 112, SAMU at 15, fire department at 17).
If you are pregnant or planning to become pregnant, do not use proto: this product could also pose risks to your unborn child.
What to do if you’re addicted?
“Proto” is a product that can be addictive. If you (or someone close to you) are having trouble controlling and/or stopping your use, talk to your doctor, a specialized addiction treatment center (CSAPA), or the Addiction Assessment and Information Center (Addictovigilance).
Youth Consumer Clinics (CJC) offer free and confidential support, including listening, counseling, and, if necessary, referral services, to users under 25 and their families and friends.
In addition, Drogues info service is Santé publique France’s national remote assistance service for drugs and addiction. Its mission is to provide information, advice, support, and guidance to the public (www.drogues-info-service.fr or 0 800 23 13 13, 7 days a week, from 8 a.m. to 2 a.m., anonymous and free of charge).
Drogues info service
Promotes access to information tailored to each individual, addressing both users and their loved ones through dedicated spaces;
helps create an open dialogue by encouraging interaction and mutual support through interactive modules (Q&A, forums, testimonials, etc.) and an individual chat service (a real-time dialogue space between the user and a professional);
facilitates referral by providing a directory of over 3,000 specialized addiction treatment facilities.
Information for Healthcare and Medical-Social Professionals
Certain signs or behaviors should alert you to potential nitrous oxide intoxication: Download the document on the diagnosis and management of nitrous oxide intoxication (updated on April 16, 2025).
Appropriate care must be offered to patients, with support provided whenever possible.
If you suspect significant nitrous oxide use with dependence, you should refer the patient to appropriate addiction treatment, particularly through the Addiction Liaison and Care Team (ELSA) in the event of hospitalization.
Do not hesitate to contact your Addiction Assessment and Information Center (Addictovigilance) or your poison control center (01 45 42 59 59).
Drug Information Service
Drogues Info Service offers drug users and their loved ones assistance, information, support, guidance, and advice online or by phone (anonymous and toll-free calls 7 days a week from 8...
