Laughing gas (Nitrous Oxide) is the mostly examined sedation technique. It was discovered in 1772.
The gas has an anxiolytic, relaxing and painkilling effect. Most people have after a few minutes an euphoric feeling, sometimes in combination with a tingling sensation in arms and legs or a warm feeling all over.
When the treatment is done the gas is elaminated from the body within 3 to 5 minutes, so that you can drive home safely.