Nitroglycerine has medical and non medical use. Medical use is in tiny quantities in a highly purified form. Non medical use is an explosive (the original use).
Nitroglycerine tablets and injection are available. Both are used to treat angina pectoris, due to narrowing of coronary arteries supplying blood to the heart. Nitroglycerine dilates these vessels and relieves the pain due to angina pectoris.