Reliable biomarkers have great significance in the investigation of alcohol consumption patterns and in the treatment of alcohol-induced diseases. Conventional alcohol tests are based on the measurement of indirect biomarkers (GGT, ALT, AST, CDT etc.) to determine the toxic effect caused by alcohol consumption. However, these indirect biomarkers are not specific enough since they are also affected by physiological and pathological conditions. Direct biomarkers to detect alcohol intake are non-oxidative products of ethanol metabolism. Ethylglucuronide (EtG) and ethylsulfate (EtS) are conjugated metabolites of ethanol and have narrow detection windows in biofluids. Additionally, severe clinical errors in results may occur stemmed from post-sampling process, either due to storage circumstances or medical conditions of the person being sampled. Phosphatidylethanol (PEth), blood-based direct alcohol biomarker, represents a group of unnatural phospholipids formed on leukocytes and predominantly erythrocyte membranes. Studies demonstrate that the most dominant of these possible forms is PEth-16:0 18:1 consisting of a palmitic and an oleic acid. The presence of PEth in blood samples is an indisputable indicator of ethanol consumption