Understanding Your Laboratory Test: What It Is, How It Is Done, and What Your Results Mean

What is this test, and what does it measure in my body?

The Barbital Hair Test is a laboratory test that measures the amount of barbital (a barbiturate medication) in a hair sample. Barbiturates are a class of medications that were historically used as sedatives, sleep aids, and to treat seizures. While less commonly prescribed today, they may still be used in certain medical situations.

How is this test performed, and what can I expect during the procedure?

A small hair sample (typically 100-200 strands) is collected from the scalp, usually from the back of the head. The hair is then sent to a laboratory where it is analyzed using specialized equipment to detect and measure barbital concentrations. Hair testing can detect substance use over a much longer period than blood or urine tests—typically weeks to months, depending on hair length.

Why might my doctor order this test, and what conditions can it help detect?

Healthcare providers may order this test to: monitor patients taking barbital medications for compliance, detect non-prescribed barbiturate use, evaluate potential drug exposure, or investigate unexplained symptoms that may be related to barbiturate use. It may also be used in forensic or addiction medicine settings.

What do my test results mean, and how should I talk with my doctor about them?

Results are reported as the amount of barbital per weight of hair (mass/mass). Your healthcare provider will interpret the results based on your medical history, medications, and the reason for testing. Positive results may indicate barbital use or exposure, while negative results suggest no detectable use within the testing window. The presence of barbital in hair does not necessarily indicate impairment—it reflects use over an extended period.