We have many ways of testing for alcohol consumption, tests which vary in immediacy and efficacy. A breathalyzer test can tell law enforcement whether you’ve been drinking that night, while a urine test indicates whether you’ve had a drink in the last few days. Once indicators are present, a fingernail test can detect alcohol consumption for nearly six months. That’s the key, though—once indicators are present. How long does it take for alcohol to show up in fingernails once the person has had a few drinks? We’ll explain in today’s post.

The Fingernail Advantage

Even though hair testing is a popular means of testing for EtG, the biomarker that indicates the metabolization of alcohol, fingernail testing presents a formidable alternative. It probably doesn’t cross your mind as you’re washing your hair in the morning, but hair and fingernails are made of the same substance—keratin, the fibrous protein that serves as a building block of our bodies. In fact, elsewhere in the animal kingdom, things such as bird feathers and rhinoceros horns are also made of keratin.

The difference between the keratin in our hair and the keratin in our nails is that the strands of proteins in our nails are about four times thicker than those on our heads. With that reinforced strength comes a greater capacity for absorbing biomarkers between fibers of keratin. If hair does a good job locking in the indicators of drug and alcohol consumption, the heavy fibrous strands of fingernails are practically the Alcatraz of biomarkers—once they get in, they’re not getting out.

The Window for Testing

Now we know that fingernails are particularly adept at collecting indicators of chemical consumption. The question remains, then: how long does it take for alcohol to show up in fingernails? While it doesn’t take place immediately, it may happen sooner than you think. As you should know, it takes the body roughly one hour to process a standard alcoholic beverage. From there, it takes an additional 24 hours for alcohol to leave the body completely. As it does, remnants of that metabolization process stay in the body for days, after which they eventually leave the body via sweat. Fingernails and toenails absorb this metabolite, ethyl glucuronide, about one week after initial consumption. Once keratin captures sufficient EtG, it can remain in detectable quantities for as long as 180 days.

A Closer Look at Fingernail Testing

Nearly everyone enjoys the occasional alcoholic beverage. This legal and generally safe usage pattern is one that even the reliable traps of fingernail fibers sometimes struggle with. If the goal of a test is to ascertain absolute abstinence, you may not find that a nail test indicates mild usage. However, when it comes to moderate drinking, sustained heavy drinking, or short bursts of binge drinking, there will be enough EtG present for enough time to indicate a problematic relationship with alcohol. Our fingernail alcohol test calls for 100 mg of fingernails or toenails—one or the other, please. Results of this test should return in about five business days.