- Have an alcohol intake that exceeds 7 units per week with no more than 3 units per day, or are unwilling to stop alcohol consumption for the duration of the study (1 unit = 12 ounces or 360 mL of beer; 5 ounces or 150 mL of wine; 1.5 ounces or 45 mL of distilled spirits), or are a regular user of known drugs of abuse