Metoclopramide (Standard) is the standard substance of Metoclopramide, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Metoclopramide (5-Chloro-2-methoxyprocainamide) is a dopamine D2 antagonist which has been used for treatment of a variety of gastrointestinal symptoms over the last thirty years. In various countries, metoclopramide is the antiemetic drug of choice in pregnant women. Findings provide reassurance regarding the safety of metoclopramide for the fetus when the drug is given to women to relieve nausea and vomiting during pregnancy. Evidence also supports its use for gastroparesis (poor stomach emptying) and gastroesophageal reflux disease. It appears to bind to dopamine D2 receptors where it is a receptor antagonist, and is also a mixed 5-HT3 receptor antagonist/ 5-HT4 receptor agonist.