How Long Does Phenobarbital Stay in Your System?

Detection Timetable Depends on Many Variables

Phenobarbitol tablets
Phenobarbital Is a Barbiturate. DEA

How long phenobarbital is detectable in the body depends on many variables, including which kind drug test is being used. Phenobarbital - which is a barbiturate - can be detected for a shorter time with some tests, but can be "visible" for up to three months in other tests.

The timetable for detecting phenobarbital in the system is also dependent upon each individual's metabolism, body mass, age, hydration level, physical activity, health conditions and other factors, making it almost impossible to determine an exact time phenobarbital will show up on a drug test.

The following is an estimated range of times, or detection windows, during which phenobarbital can be detected by various testing methods:

How Long Does Phenobarbital Stay in Urine?

Phenobarbital can be detected in a urine test for up to 2-3 weeks

How Long Does Phenobarbital Remain in the Blood?

Blood tests for Phenobarbital can detect the drugs for up to 5-10 days

How Long Can Phenobarbital Be Detected in Saliva?

A saliva test can detect Phenobarbital for 1-10 days

How Long Does Phenobarbital Remain in Hair?

Phenobarbital, like like many other drugs, can be detected with a hair follicle drug test for up to 90 days.

Preventing a Phenobarbital Overdose

Phenobarbital is in a class of medications called barbiturates. It works by slowing activity in the brain and can cause relaxation and sleepiness. Phenobarbital is prescribed to control seizures.

To prevent an overdose, do not take larger doses, take it more often, or take it for a longer time than prescribed by your healthcare provider.

Barbiturates are also highly addictive and should be taken only as directed.

Symptoms of Phenobarbital overdose can include:

In case of a Phenobarbital overdose, call the poison control center at 1-800-222-1222.

If the person has collapsed or is not breathing, call 9-1-1 immediately.


Always Test Clean. "What Are Drug Detection Times?" Drug Test Facts Accessed December 2015

American Association for Clinical Chemistry "Drugs of Abuse Testing." Lab Tests Online. Revised 2 January 2013.

LabCorp, Inc. "Drugs of Abuse Reference Guide." Accessed March 2013.

OHS Health & Safety Services. "How long do drugs stay in your system?." Accessed March 2013.

National Institue on Drug Abuse. "Phenobarbital." Drugs, Herbs and Supplements May 2013

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