EtG: Nail vs. Body Hair

Liz Wood AlphaBiolabs

By Liz Wood, Health Testing Specialist at at AlphaBiolabs
Last reviewed: 26/05/2023

Consumed alcohol circulates in the bloodstream and a proportion of it and its metabolites become incorporated into the keratin that makes up nails and hair. This tough, fibrous protein traps any biomarkers ready for detection.
Therefore, both hair and nails can be used for legal alcohol testing and have similar turnaround times. In the case of body hair and nail alcohol testing, only one long-term marker of alcohol called ethyl glucuronide (EtG) can be detected. For this reason, we would also recommend a blood test to detect alcohol biomarkers, in conjunction with clinical assessment, to gain a greater insight into an individual’s alcohol use.

Nail alcohol testing

EtG biomarkers become trapped within the keratin fibres along the length of a nail, which can provide a detection period of up to 12 months.

Approximately 10 mg of nail is required for the test. The nail is collected as close to the nail bed as possible. If the nail is long (5 mm or above) then only one would be required. If the nails are short then it may be best to take clippings from several nails. Toe nails as well as finger nails can be used, but not a mixture of both. The advantages of using toe nails is that there is less potential for environmental exposure.

Acrylic nails, Shellac and other forms of nail varnish would need to be removed as this may damage the surface of the nail and impact on the results.

Window of detection: up to a 12-month overview.

Advantages: simple-to-collect sample to measure levels of EtG. Ideal for those cases where hair testing is not possible (such as the donor has no or little hair, for religious reasons, and for those concerned with their appearance).

Body hair alcohol testing

Biomarker testing in body hair can establish an overview of a person’s alcohol consumption for up to 12 months. AlphaBiolabs determines alcohol abuse in head hair by detecting two metabolites of alcohol: EtG and fatty acid ethyl esters (FAEEs).

These markers of alcohol intake are incorporated into the hair via different routes: EtG via sweat and FAEEs via sebum (an oily substance secreted by glands in the scalp). Performing these two different types of hair analyses can assist in building evidence to support the diagnosis of chronic excessive alcohol consumption with a greater degree of certainty.

Head hair is preferred over body hair for alcohol testing. However, body hair can be useful to measure EtG if head hair is not available. The time period would also be more approximate due to the nature of body hair growth. Chest, arm, leg and beard hair can all be analysed.

Window of detection: up to 12-month overview of EtG only.

Advantages: useful for measuring EtG if head hair is not available.

Sample collection options

Nail clipping and body hair samples would need to be collected under chain of custody conditions to support legally defensible results.

One of our trained sample collectors could visit a donor at any convenient address. Alternatively, the donor could visit our Dublin Walk in Centre.

If you have further questions about EtG: nail vs. body hair

For expert advice on alcohol testing solutions, please call our Customer Services team on 01 402 9466 or email us at

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Liz Wood AlphaBiolabs

Liz Wood

Health Testing Specialist at at AlphaBiolabs

Liz joined AlphaBiolabs in 2021, where she holds the role of Health Testing Specialist.

As well as overseeing a range of health tests, she is also the lead on several validation projects for the company’s latest health test offerings.

During her time at AlphaBiolabs, Liz has played an active role in the validation of the company’s Genetic Lactose Intolerance Test and Genetic Coeliac Disease Test.

An advocate for preventative healthcare, Liz’s main scientific interests centre around human disease and reproductive health. Her qualifications include a BSc in Biology and an MSc in Biology of Health and Disease.

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