1.1. Nitrous oxide, also known as ‘laughing gas’, is a colourless, sweet-tasting gas discovered by Joseph Priestly in 1772.
1.2. Nitrous oxide (combined with oxygen) has been used as an anaesthetic and analgesic in medical and dental settings. Also, it has many other legitimate industrial and commercial uses, for example, as a food additive, propellant in catering and component of vehicle fuel.
1.3. Furthermore, nitrous oxide is the focus of pre-clinical and clinical research for a range of potential therapeutic uses, for example, as an acute antidepressant, as a treatment for alcohol withdrawal and as a potential intervention for posttraumatic stress disorder (PTSD).
1.4. For over 200 years nitrous oxide has also been used for its psychoactive effects. When inhaled nitrous oxide can produce euphoria, mild perceptual changes and uncontrollable laughter, which last for a short period of time (30 seconds to 1 minute). When used for non-medical purposes, nitrous oxide is commonly taken by inhalation directly from canisters or balloons/plastic bags containing the gas.
1.5. The precise mechanism of action is uncertain, but anaesthesia is widely believed to be due to inhibition of excitatory glutamatergic neurotransmission via non-competitive inhibition of N-methyl-D-aspartate (NMDA) receptors in the brain. NMDA receptor inhibition may also be responsible for euphoric and hallucinogenic effects (van Amsterdam et al., 2015).
1.6. The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) recently published an extensive review of nitrous oxide use. This included the current situation and responses to nitrous oxide use in several countries, including Denmark, Ireland, France, Lithuania, the Netherlands and Portugal (EMCDDA, 2022). Most countries have implemented measures to restrict the supply of nitrous oxide and provide targeted health promotion...

[See also, Government response: ACMD nitrous oxide review]