Nitroglycerin (NG), also known as nitroglycerine, trinitroglycerin (TNG), trinitroglycerine, nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a heavy, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, yet the traditional name is often retained. Invented in 1847, nitroglycerin has been used as an active ingredient in the manufacture of explosives, mostly dynamite, and as such it is employed in the construction, demolition, and mining industries. Since the 1880s, it has been used by the military as an active ingredient, and a gelatinizer for nitrocellulose, in some solid propellants, such as cordite and ballistite.

Nitroglycerin is a major component in double-based smokeless used by reloaders. Combined with nitrocellulose, there are hundreds of powder combinations used by rifle, pistol, and shotgun reloaders

Nitroglycerin belongs to a group of drugs called nitrates, which includes many other nitrates like isosorbide dinitrate (Isordil) and isosorbide mononitrate (Imdur, Ismo, Monoket).^[24] These agents all exert their effect by being converted to nitric oxide in the body by mitochondrial aldehyde dehydrogenase,^[4] and nitric oxide is a potent natural vasodilator.

In medicine, nitroglycerin is used as a medicine for angina pectoris, a painful symptom of ischemic heart disease caused by inadequate flow of blood and oxygen to the heart and as a potent antihypertensive agent. Nitroglycerin corrects the imbalance between the flow of oxygen and blood to the heart.