Nitrous oxide (N2O) Sedation (Laughing Gas): Nitrous oxide (N2O) is simply a gas which you can breathe in. It has no color, smell, and doesn't irritate. it kills pain - and it induces a pleasureable feeling. After 5 minutes or so of breathing in the gas, you should feel a euphoric feeling spread throughout your body. It really kind of feels like a 'happy drunk' feeling. Some people find that there are auditory or visual effects as well.