Ethanol monitoring     

Support recovery through direct ethanol biomarker testing

Alcohol, or ethanol, is the most commonly abused drug in the world and is regularly consumed by more than half of adults in the United States. Excessive alcohol consumption, which includes binge drinking and heavy binge drinking, is the leading cause of preventable death in the U.S. Alcohol use disorder (AUD), defined as a pattern of alcohol use involving inability to control drinking, preoccupation with alcohol, and continued use even when it causes problems, ranks among the leading health problems worldwide and is estimated to affect 300 million people.1

Because hazardous drinking practices and associated morbidity remain underdiagnosed, routine screening for unhealthy alcohol use is recommended by the U.S. Preventive Services Task Force as a cost-effective, clinical preventive service. Further, the incorporation of alcohol biomarker testing is recommended by the American Society of Addiction Medicine and the American Psychiatric Association to help diagnose AUD and support patient recovery.2

By the numbers

14.8 Million

14.8 million Americans have AUD3


140,000 deaths in the U.S. each year caused by excessive alcohol use4

$249 Billion

Annual financial burden of AUD was $249 billion in 20104 

Optimized testing

Mayo Clinic Laboratories offers a menu of direct ethanol biomarker testing to accurately assess alcohol use and AUD. As opposed to the limited sensitivity and specificity of indirect ethanol biomarker testing, direct biomarker testing offers heightened sensitivity and specificity to identify AUD. This methodology enables detection of even small amounts of ethanol eliminated via non-oxidative pathways into ethyl glucuronide (EtG), ethyl sulfate (EtS), and phosphatidylethanol (PEth).6 Because these direct alcohol biomarkers have a longer half-life and extended detection window, alcohol consumption over a period of several days can be more accurately assessed.

Additional benefits of biomarker testing include:

  • Improved analysis of the specific role alcohol plays on an individual’s health.7
  • Test results clarify actual amounts of recent consumption, which, combined with questionnaires, can support initiating clinical interventions.

Precision answers

Our urine alcohol testing offers clinical specificity to evaluate for alcohol use through the detection of EtG and EtS. In addition, we offer blood biomarker testing to evaluate for PEth, which provides an expanded window of detection to identify ethanol consumption. PEths, a group of phospholipids formed in the presence of ethanol, phospholipase D, and phosphatidylcholine, are incorporated into the phospholipid membrane of red blood cells. Based on blood concentrations of PEth, it is possible to determine recent alcohol consumption and how much has been taken for several weeks following the last use.

Key urine alcohol biomarker testing

ETGR  | Ethyl Glucuronide Screen with Reflex, Random, Urine

Clinical utility

  • Detects EtG, which is a direct metabolite of alcohol formed by enzymatic conjugation of ethanol with glucuronic acid. Alcohol in urine is normally detected for only a few hours, whereas EtG can be detected in the urine for up to five days.
  • Testing begins with a screening assay. If positive, then the liquid chromatography-tandem mass spectrometry confirmation with quantification (Mayo ID: ETGC) will be performed at an additional charge.
  • Care should be taken when interpreting results, since there are many factors (e.g., fluid intake) that might influence the urine test result. It is possible that substances other than those investigated in the specific study may interfere with the test and cause false positive or false negative results.

ETGC  | Ethyl Glucuronide Confirmation, Random, Urine

Clinical utility

  • Uses liquid chromatography/tandem mass spectrometry (LC-MS/MS) to quantify levels of both ethyl glucuronide (EtG) and ethyl sulfate (EtS) in urine.
  • A positive interpretation will be given if either the EtG result is greater than or equal to 250 ng/mL, and/or EtS is greater than or equal to 100 ng/mL.
  • Combined testing provides sensitivity and specificity to low levels of ethanol.
    • When screening for only EtG, false positives may occur.


  • Offers an extended window of detection that can reliably identify alcohol consumption in urine up to five days.
  • Can help facilitate diagnosis.
  • Can help monitor ethanol abstinence or relapse in outpatients treated for alcohol-related problems.

Key blood alcohol biomarker testing

PETH  | Phosphatidylethanol Confirmation, Whole Blood

Clinical utility

  • Uses liquid chromatography/tandem mass spectrometry (LC/MS-MS) to measure PEth concentrations in blood.
  • Measures and reports the two most common PEth homologues: PEth 16:0/18:1 (POPEth) and PEth 16:0/18:2 (PLPEth), which, combined, account for over 60% of all the observed PEth homologues in the blood.


  • Identifies relapse, especially to heavy ethanol consumption.
  • Helps monitor ethanol abstinence over time.
  • Offers a detection window of two to four weeks in the blood. Among individuals who chronically or excessively consume alcohol, the detection window can be longer.

To assess concurrent substance use and abuse, consider ordering a comprehensive urine drug testing profile.

ADMPU  | Addiction Medicine Profile with Reflex, 22 Drug Classes, High Resolution Mass Spectrometry and Immunoassay Screen, Random, Urine

Clinical utility

  • Detects recent drug use involving alcohol, amphetamine-type stimulants, barbiturates, benzodiazepines, cocaine, opioids, nicotine, and THC-COOH in urine.
  • Useful for the assessment and management of patients at risk for substance use disorders.

In instances where nicotine testing is not required, our enhanced controlled substance monitoring profile can provide accurate answers about other substance use.

Interpretation EtG/EtS8

Interpretation of PEth8

A Test in Focus

Paul Jannetto, Ph.D., describes Mayo Clinic Laboratories' new direct biomarker test for alcohol consumption. PETH is a blood test with a window of detection of about two to four weeks — compared with five days for urine-based screening for alcohol use.

Learn more about how to order these tests at your institution.


Learn more about alcohol use disorder

Learn more about ongoing research at Mayo Clinic on alcohol and substance abuse disorder  


  1. U.S. Preventive Services Task Force. (2018). Final recommendation statement: Unhealthy alcohol use in adolescents and adults: Screening and behavioral counseling interventions. Retrieved from
  2. Jarvis M., Williams J., Hurford M., et al. Appropriate use of drug testing in clinical addiction medicine. J Addict Med. 2017 May/Jun;11(3):163-173. doi:10.1097/ADM.0000000000000323
  3. Key Substance Use and Mental Health Indicators in the United States: Results from the 2018 National Survey on Drug Use and Health (
  4. Centers for Disease Control and Prevention. Alcohol-Related Disease Impact (ARDI) website. Accessed April 19, 2022.
  5. Sacks JJ, Gonzales KR, Bouchery EE, Tomedi LE, Brewer RD. 2010 National and state costs of excessive alcohol Consumption. Am J Prev Med. 2015;49(5):e73–e79
  6. Alcohol Facts and Statistics | National Institute on Alcohol Abuse and Alcoholism (NIAAA) (
  7.  Chaudhari R., Moonka D., Nunes F. Using biomarkers to quantify problematic alcohol use. J Fam Pract. 2021 Dec;70(10):474-481. doi:10.12788/jfp.0317.
  8. Kapur B, Aleksa K., What the lab can and cannot do: clinical interpretation of drug testing results. Crit Rev Clin Lab Sci. 57:8, 548-585. doi:10.1080/10408363.2020.1774493
  9. Niemela, O. Biomarker-based approaches for assessing alcohol use disorders. Int J Environ Res Public Health. 2016 Jan 27;13(2):166. doi:10.3390/ijerph13020166
  10. Hakim F, Wiart JF, Ménard O, Allorge D, Gaulier JM. Dosage sanguin du phosphatidyléthanol [Phosphatidylethanol blood analysis]. Ann Biol Clin (Paris). 2019 Dec 1;77(6):638-644. French. doi:10.1684/abc.2019.1499. PMID: 31859640.
  11. Ulwelling W, Smith K. The PEth blood test in the security environment: what it is; why it is important; and interpretative guidelines. J Forensic Sci. 2018 Nov;63(6):1634-1640. PMID: 30005144