Glutathione (GSH) is a principal cellular scavenger of free radicals. Chronic alcohol abuse, as well as liver disease, induces a decrease of hepatic GSH. We evaluated the effect of GSH administration (2.4 g day-1 in saline i.v. for 15 days) on the concentration of GSH in plasma and erythrocytes and on liver function tests, including galactose and antipyrine tests. We studied 40 alcoholic cirrhotic patients: 22 treated with GSH (10 persistent alcohol abusers and 12 weaning from alcohol during the study) and 18 treated with saline only (8 persistent alcohol abusers and 10 abstainers). Treatment with GSH improved the concentration of GSH in plasma and erythrocytes only in abstainers from alcohol; it did not affect liver function tests or galactose clearance. Persistent alcohol consumption significantly prolonged antipyrine metabolism; GSH administration counteracted this effect.