Hair vs. Nails Alcohol Testing

Gail Evans, Alphabiolabs

By Gail Evans, Technical Trainer at AlphaBiolabs
Last reviewed: 19/06/2020

Head hair vs. body hair vs. nails for alcohol testing

To determine which is the best method for your case, you need to ascertain what period of detection you wish to cover. You also need to establish whether your client has the required amount of head hair, or body hair, or nail clipping samples.

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.

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.

Hair alcohol testing

Biomarker testing in head hair can establish a person’s history of alcohol consumption for up to 6 months. The recommended minimum length of hair is a 3 cm section taken from nearest the scalp which covers a 3-month time period. This is consistent with the consensus on hair alcohol testing for chronic excessive alcohol consumption published by the Society of Hair Testing (SoHT) in June 2019 [1].

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). The reasons that both EtG and FAEE markers are analysed is because they are affected by external factors in different ways.

Therefore, 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.

Window of detection: 3- or 6-month overview.

Advantages: useful for detecting long-term alcohol use. History of alcohol use can be established. Chronic and excessive levels can be measured.

Body hair alcohol testing

Head hair is preferred over body hair for alcohol testing because it can detect both EtG and EtPA. 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 be analysed to provide up to a 12-month overview.

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

Advantages: useful for detecting long-term alcohol use. History of alcohol use can be established. Chronic and excessive levels can be measured.

Nail alcohol testing

EtG biomarkers trapped within the keratin fibres along the length of a nail 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).

If you have further questions about hair vs. nails alcohol testing

For expert advice on legal alcohol testing solutions, please call our Customer Services team on 0333 600 1300 or email us at

[1] Consensus of the Society of Hair Testing on hair testing for chronic excessive alcohol consumption 2011.

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Gail Evans, AlphaBiolabs

Gail Evans

Technical Trainer at AlphaBiolabs

A professionally-trained forensic scientist, Gail joined AlphaBiolabs in 2012 and holds the role of Technical Trainer.

Her day-to-day responsibilities include delivering in-depth training sessions both internally and externally, covering DNA, drug, and alcohol testing.

Before joining the company, Gail was a practicing forensic scientist with 25 years’ experience working for the Forensic Science Service, attending scenes of crime, and analysing physical and biological material with potential evidential value.

Gail also holds qualifications in chemistry and is a Lead Auditor for the ISO 9001 standard, the international standard for quality management.

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