It is impossible with this biomarker to distinguish small amounts of drinking from extraneous exposure to alcohol.

[5] A growing number of articles are documenting the high sensitivity and specificity of hair (or nail) EtG for detection of heavy drinking.

[6][7][8][9][10] EtG testing in hair specimens was previously attempted by laboratories in the United Kingdom, but has suffered from numerous lawsuits.

Due to the concerns of legal risk, few laboratories offer this type of testing anymore, as it has been determined to be unreliable and unsupportable.

"[13] Other experimental serologic tests (biomarkers) for recent alcohol use include 5-hydroxytryptophol, ethyl sulfate, phosphatidyl ethanol, sialic acid level, β-hexosaminidase, mitochondrial AST levels, and alcohol metabolites such as erythrocyte acetaldehyde and acetaldehyde adducts.