Background <p>Alcohol consumption may induce multiple disorders, and decreased alcohol consumption has been proved to be effective to reduce the incidence of alcohol-associated diseases and mortality. Pharmacotherapy is the most common option for the management of alcohol problems; however, it suffers from multiple problems. Non-pharmaceutical interventions are therefore of urgent need to change alcohol intake among alcohol users. Aldehyde dehydrogenase 2 (ALDH2), which encodes the <i>ALDH2</i> gene, is an important enzyme in ethanol metabolism. Previous studies have demonstrated that individuals harboring <i>ALDH2</i> gene mutations are more likely to present discomfort symptoms and are more susceptible to multiple cancers. It is hypothesized that <i>ALDH2</i> gene testing may reduce alcohol consumption and the incidence of alcohol-associated disorders among unhealthy alcohol users.</p> Methods <p>A single-center, open-label, randomized, controlled clinical trial was designed, aiming to recruit 940 unhealthy alcohol users at ages of 18 to 60&#xa0;years. All participants are randomized into the interventional and control groups, and both groups are given alcohol consumption health education. In addition, blood samples are collected from participants in the interventional group for <i>ALDH2</i> gene testing, with testing reports issued, while <i>ALDH2</i> gene testing is not performed in the control group. Changes in alcohol intake, hazardous drinking days, and alcohol-associated adverse events are recorded prior to and post-interventions. The primary outcome is alcohol intake, and the secondary outcomes are hazardous drinking days and alcohol-associated adverse events.</p> Discussion <p>This trial will provide strong evidence regarding the impact of <i>ALDH2</i> gene testing on alcohol use behaviors.</p> Trial registration <p>The study has been registered in the Chinese Clinical Trial Registry (registration no. ChiCTR2400087726) on 2 August 2024.</p>