Biotech & Biomedical/alcohol


QUESTION: Would phenoxyethonol present in a shampoo used regularly effect a hair strand test ? If so in what way would it do so

ANSWER: Hi, Jon,

Thanks for your question.

I assume you are thinking about the hair test for ethanol and its metabolites.

Phenoxyethanol is not metabolised to ethanol in the body but actually to phenoxyacetic acid so use of shampoo containing phenoxyethanol would not lead to any build up of ethanol or its known metabolites in hair.

Hope this is helpful to you.

Best wishes,


[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: Do you know of any chemicals or foods which would effect the test to create a positive FAEE and a negative EtG outcome when there has been no alcohol intake over a period of more than twelve months. Any information about how this result could occur would be very helpful.

Hi, Jon,

Thanks for your follow- up question.

There is documented evidence that FAEE can be found in the hair of teetotallers in the absence of EtG. Most labs would look for both as evidence of alcohol use.

See example below:

Comparison of ethyl glucuronide and fatty acid ethyl ester concentrations in hair of alcoholics, social drinkers and teetotallers.
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Best wishes,


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Dr.Paul Skett


drug metabolism or biotransformation from basic to advanced, hepatocytes from basic to advanced, drug toxicity and side effects, alcohol clearance and levels


32 years research experience in above areas, 30 years educational experience in University. Retained expert for numerous legal firms dealing with matters of drugs (legal and illegal)and alcohol.

B.Sc(Hons) Biochemistry, University of Liverpool, UK
fil.dr. (Medical Chemistry) Karolinska Institute, Stockholm, Sweden

Fellow of the British Pharmacological Society

Fellow of the Higher Education Academy

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