There is no such thing as which is safer, glutamine or melatonin. Glutamine can be used to treat insomnia, while melatonin belongs to the health care products, does not have a therapeutic effect, to improve sleep has a certain health care role, should be selected under the guidance of a doctor. 1. Glutamine: is a drug that can be used to improve endocrine disorders and regulate autonomic dysfunction, can also be used to improve sleep and regulate neurasthenia. Some people may experience constipation, nausea, vomiting and other symptoms after taking it. Gastric and duodenal ulcer patients, allergies, use with caution. 2. Melatonin: a health product, does not have a therapeutic effect, can not replace the drug. The secretion of melatonin is affected by sleep rhythm and light, and the secretion of melatonin increases when you fall asleep at night, taking melatonin has certain health effects on improving sleep. The use may inhibit the secretion of gonadal hormones, and excessive use may affect liver and kidney function. Drugs should be taken under the guidance of a doctor in accordance with the dose, to avoid unauthorized use, causing unnecessary damage to the body.