Melatonin (Standard) is the standard substance of Melatonin, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Melatonin (Melatonine) is a natural hormone secreted by the pineal gland that activates melatonin receptors. Melatonin is a hormone that regulates the biological clock and also has antioxidant and anti-inflammatory activities.