Saliva, also known as saliva, does not stop pain. Saliva is a colorless, odorless, translucent liquid. In addition to water, saliva also includes organic and inorganic substances. Organic matter has mucin, immunoglobulin, salivary amylase, lysozyme, etc., and inorganic matter has sodium, potassium, calcium, chlorine and carbon dioxide. Its chemical composition is diverse and has the physiological effects of moisturizing mucous membranes, cleansing the oral cavity, promoting starch digestion, and treating some traumas. It has been reported that French researchers have found a new pain-relieving substance, opiorphin, in saliva, which is a natural substance in the human body that can play a role in relieving pain. The substance and morphine-type narcotic painkillers work in a similar way. However, the study found that the substance is unlikely to play a role in pain relief in the human body, and its role is to protect the body’s chemicals from destruction. Therefore, saliva contains painkillers, but does not have a painkilling effect in the human body.