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PEth Testing

  • Most accurate blood alcohol test
  • Detect chronic and single-drinking episodes
  • Detected in blood after 1–2 hours
  • Monitor abstinence, drinking behaviour and identify relapse
  • Verify patterns of alcohol consumption

PEth is a direct biomarker of alcohol

Biomarkers are used to detect the consumption of alcohol or its harmful effects on the body. There are two types: Direct and indirect biomarkers.

Direct biomarkers are created when ethanol is metabolised or reacts with substances in the body.

Indirect biomarkers are enzymes or cells, which undergo measurable changes in response to acute or chronic alcohol consumption. Indirect biomarkers are measured in the carbohydrate deficient transferrin (CDT), liver function test (LFT) and mean corpuscular volume (MCV) tests (see Blood alcohol testing). While medically useful, these blood tests generally require the daily consumption of over 60 g/day of alcohol over several weeks to cause clinically significant elevations. This means that either normal or chronic and excessive levels of alcohol can be detected.

Phosphatidylethanol (PEth) is the most accurate blood test to determine alcohol abuse because is a direct biomarker of alcohol. This means that it can only be detected when alcohol has been consumed. Its high specificity (48–89%) and sensitivity of 88–100% is because it is directly related to alcohol consumption.

We provide the fastest, most cost-effective legal alcohol testing in the UK

What is PEth alcohol testing?

PEth is actually an abnormal phospholipid, which is produced after alcohol exposure in red blood cell membranes. It requires ethanol for its production and is formed on the surface of a red blood cell when the alcohol reacts with phosphatidylcholine.

PEth production begins as soon as ethanol is consumed and accumulates in blood with frequent alcohol consumption. The result provides a detection period of up to 3–4 weeks. However, the greater the exposure and/or larger the binge session(s), the longer the period of detection.

Accuracy of PEth alcohol testing

Experiments have shown that PEth can be detected in blood after 1–2 hours and for up to 12 days after a single drinking episode. In addition, daily alcohol consumption of more than 60 g ethanol can clearly be distinguished from lower alcohol consumption. As such, PEth testing can detect chronic and single-drinking episodes. It can also be used to monitor abstinence, drinking behaviour and identify relapse. PEth analysis can also verify whether an individual has changed their pattern of alcohol consumption. Indirect biomarkers are unable to monitor abstinence or episodes of binge drinking.

PEth is also the only blood alcohol test that can be undertaken during pregnancy.

PEth level (µg/L)
< 10Abstinence or very low alcohol consumption in the past month.
10–35Low/occasional alcohol consumption in the past month.
35–210Social/moderate alcohol consumption in the past month.
> 210Excessive alcohol consumption in the past month.
In terms of all alcohol tests, PEth is second to the detection of ethyl glucuronide (EtG), which is another direct metabolite of ethanol, in hair alcohol testing. However, PEth analysis has the advantage of allowing faster verification as to whether an individual has changed their drinking behaviour.

Contact AlphaBiolabs to order a PEth alcohol test or other alcohol testing solution including instant breath tests, blood analysis and 3- or 6-month hair analyses to show alcohol consumption over a period of time. Real-time results are also available with SCRAM Continuous Alcohol Monitoring®. For expert advice, please call 0333 600 1300 or email us at

Enquire about PEth testing now. Call us on 0333 600 1300