Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula N ₂O. At room temperature, it is a colourless non-flammable gas, with a slight metallic scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidizer similar to molecular oxygen. One of its benefits is that it can be inhaled, so it is recommended for patients who have a fear of needles. Because it’s a gas, it reaches the brain quickly to induce a state of relaxation.