The shelf life of nitroglycerin is generally one year. If patients repeatedly open the bottle to take the medicine every day, nitroglycerin will be affected by temperature, humidity and sunlight, and the validity period will be reduced to 3-6 months. Therefore, it is necessary to pay attention to the expiration date when using nitroglycerin, and each time you take the medicine, you should open and cap it quickly, and then cap the bottle tightly, and it is better to replace nitroglycerin once every 3-6 months. Not only that, the storage conditions of nitroglycerin are very demanding, and it should be kept in a place below 20 degrees, and it must be kept away from light. Some patients put nitroglycerin in plastic bags, which are not protected from light and heat, and have a certain adsorption effect, which will lead to the volatilization and oxidation of the effective drug components in nitroglycerin over time, and the drug will fail.