This private blood test measures phosphatidylethanol (PEth), a direct cell-membrane biomarker formed only when ethanol is present in the body. The catalogue test price is £146.88 plus a £50 phlebotomy fee, with results available in 5-7 days.
Unlike liver enzymes or MCV, which can be altered by non-alcoholic liver conditions or medicines, PEth specifically reflects alcohol intake over the preceding 2 to 4 weeks.
Written by Mr Stephen Lingam. Reviewed by Dr Mohammad Bakhtiar (GMC 4694470) on 18/10/2026.
PEth typically reflects alcohol consumption over the past 2 to 4 weeks, depending on the amount and frequency of drinking.
Yes. PEth is formed directly from ethanol on red blood cell membranes, so it is not raised by non-alcoholic fatty liver disease, medications or genetic transferrin variants.
Yes. Our phlebotomists collect a venous EDTA blood sample at 117a Harley Street, avoiding the false positives that can occur if alcohol skin wipes contaminate a finger-prick sample.
Yes. You can book PEth individually or choose the Alcohol Profile, which combines PEth, CDT, liver function tests, blood alcohol and MCV under one £50 phlebotomy fee.