RU-21 RU-21 is an all-natural supplement that has been clinically proven to regulate alcohol metabolism in order to prevent alcohol-related damage to the vital organs of the body. RU-21 was developed by the scientists at the Russian Academy of Sciences in the course of a 25 year-long research project studying alcohol metabolism. RU-21 neutralizes the effects of acetaldehyde by regulating the metabolic process of alcohol in the body. RU-21 slows down the process of ethanol oxidation into acetaldehyde, so less acetaldehyde occurs in the first place, and then speeds up the process of decomposition of acetaldehyde and acetic acid into water and carbon dioxide.