Introduction. Mineral waters are administered in medical hydrology as prophylaxis or treatment, both internal and external. The mineral water from spring 3 in Baile Tusnad, with a total mineralization of 3351.0 mg/l, is recommended in chronic liver diseases. From the point of view of its chemical composition, it contains sodium chloride, iron, carbon dioxide, traces of iodine, boron. Some studies have evaluated the therapeutic properties of mineral water as a whole, but it is considered that the different components of the waters may also act in an antagonistic manner. Material and method. For the experimental study, 25 white rats were used. The animals were assigned to 3 groups: group I – negative control, 5 animals; group II – positive control, 6 animals; group III – experimental group, 14 animals. Group I animals received tap water (50-75 ml/animal/day) throughout the experiment; group II and III animals received 12% ethyl alcohol (12-15 ml/animal/day) during the first 70 days. Over the last 30 days, group II animals received tap water (50- 75 ml/animal/day), while group III animals were administered mineral water from spring 3 in Baile Tusnad (50-75 ml/animal/day). Before starting alcohol administration, at 70 days, after alcohol administration, and at 100 days, after administration of tap water and mineral water for 30 days, 0.1 ml serum/blood sample from each animal was collected in order to determine the values of some biochemical components: transaminases, glycemia, total protein, urea, creatinine, sodium, calcium, iron, potassium. Results and discussions. Transaminases, particularly aspartate aminotransferase (ASAT), increased after alcohol consumption, but after mineral water consumption for 30 days, they decreased more compared to the group that drank only tap water. Renal function was not affected. There were slight increases in glycemia and total protein values after alcohol administration, which decreased after water administration. During the study, the blood iron value statistically significantly increased at 100 days compared to day 70, p<0.005. Sodium (Na) and potassium (K) values increased on day 70 after alcohol consumption, but on day 100 they decreased to normal in both groups. A slight increase in calcium ion (Ca) levels was observed in the group that consumed mineral water compared to the group that drank tap water, but without statistical significance. Conclusions. Both the indications and the methods of treatment are based on pharmacodynamic effects in the pre-absorption phase and after absorption of the water in the digestive tract. However, administration of mineral water requires careful monitoring of some biochemical components after its consumption.