Barbiturates Drug Test
Updated October 16, 2026
Barbiturates are older sedatives, such as phenobarbital, butalbital and secobarbital, still prescribed for seizures, and butalbital appears in some migraine medicines.
The Barbiturates panel is one of the 14 on every Testr urine drug test, read on site by a certified collector at your door anywhere in the Los Angeles area. On a Testr report it is printed as BAR (Barbiturates).
How long do barbiturates stay in your system?
That range is typical rather than a guarantee: how much was taken, how often, body weight and hydration all move it.
The screening cutoff above is the level at or above which the on-site cassette reads positive. Below it the panel reads negative even when a trace is present, which is why the cutoff matters as much as the number of days.
Can a prescription cause a positive on the Barbiturates panel?
A valid prescription can cause a positive. Lab confirmation reports measured levels, and every laboratory report goes to a Medical Review Officer (MRO), a physician who reviews laboratory-confirmed results and accounts for valid prescriptions before the report is released.
What does a positive on the Barbiturates drug test panel mean?
The on-site read is a drug screen. It reports positive or negative against the screening cutoff, not a measured level. Laboratory confirmation is what produces a number: a CAP-accredited laboratory quantifies the specimen by LC-MS/MS and reports measured levels, in about 72 hours. Every laboratory report goes to a Medical Review Officer (MRO), a physician who reviews laboratory-confirmed results and accounts for valid prescriptions before the report is released. Confirmation can be added when you book, or from the app within 2 hours of collection, while the specimen is still viable.
Phenobarbital, butalbital and the BAR panel
Barbiturates are older sedatives, and the ones that still turn up on a drug test arrive by a few familiar routes. Phenobarbital is prescribed for seizures. Butalbital is an ingredient in migraine and headache medicines such as Fioricet and Fiorinal. Secobarbital, sold as Seconal, is a short-acting barbiturate. The BAR panel screens the whole class at 300 ng/mL, and how long a positive lasts depends on which barbiturate it was.
Short-acting and long-acting barbiturates
The window shown above spans a wide range, and in practice that splits the panel in two. A short-acting barbiturate such as secobarbital clears in 1-4 days, while long-acting phenobarbital can be detectable for two to three weeks. The cassette cannot tell one barbiturate from another; it reads the class against one cutoff and reports positive or negative, and only the laboratory names the drug.
Barbiturates are not benzodiazepines
Both are sedatives, but they are separate drug classes, and the cassette reads them on separate strips. Xanax, Valium, Klonopin and Ativan read on the BZO panel, not on BAR, and a barbiturate prescription is not an explanation for a BZO positive. Laboratory confirmation measures butalbital and phenobarbital at 200 ng/mL each and secobarbital at 100 ng/mL, so the report names the barbiturate behind a positive BAR line and gives its level.
Barbiturates at a glance
| Barbiturate | Where people meet it | Laboratory cutoff |
|---|---|---|
| Phenobarbital | prescribed for seizures; long-acting | 200 ng/mL |
| Butalbital | Fioricet, Fiorinal and other headache medicines | 200 ng/mL |
| Secobarbital | Seconal; short-acting | 100 ng/mL |
All three read on the same BAR line at the 300 ng/mL screening cutoff, so the rapid result is one positive or negative for the class. The laboratory column is what confirmation adds: each barbiturate measured on its own, at its own cutoff, by LC-MS/MS.
Other sedatives sit outside the BAR line entirely. Zolpidem (Ambien) is on the laboratory menu under sedative hypnotics at 1 ng/mL, and carisoprodol (Soma) and meprobamate are listed under muscle relaxants at 100 ng/mL each; none of them has a rapid panel on the cassette.
What BAR means on the report
What does BAR mean on a drug test?
BAR stands for barbiturates. On a Testr report, and on most test cups, this panel is printed as BAR. On a Testr screen the BAR panel reads positive at or above 300 ng/mL, and short-acting types clear in 1-4 days; long-acting phenobarbital can be detectable for two to three weeks.
What is the BAR cutoff on a drug test?
300 ng/mL on a Testr screen: at or above that level the BAR panel reads positive, below it negative. Other cups can print BAR with a different cutoff. Laboratory confirmation applies its own cutoff to each compound it measures and reports the measured level rather than a positive or negative.
Every code on the cassette, with its cutoff and detection window, is on one page: drug test abbreviations, decoded.
More questions about barbiturates
Does Fioricet show up on a drug test?
Yes. Fioricet contains butalbital, a barbiturate, and the BAR panel screens for the class at 300 ng/mL. Fiorinal, another butalbital medicine, reads the same way, and a valid prescription can cause a positive; laboratory confirmation measures butalbital itself.
How long does phenobarbital stay in urine?
Longer than most barbiturates. Long-acting phenobarbital can be detectable for two to three weeks at the 300 ng/mL screening cutoff, while short-acting types clear in 1-4 days. How much was taken and how often both move it.
Is the barbiturates panel on a 10-panel drug test?
Often. Barbiturates are one of the additions a 10-panel kit makes most often, along with benzodiazepines and methadone, but they are not on a standard 5-panel. BAR is on every Testr visit.
Is a barbiturate the same as a benzodiazepine on a drug test?
No. They are separate classes on separate strips: barbiturates read on BAR, and benzodiazepines such as Xanax or Klonopin read on BZO. A prescription for one does not account for a positive on the other's line.
Does Seconal show up on a drug test?
Yes. Seconal is secobarbital, a short-acting barbiturate, so it reads on the BAR panel at 300 ng/mL; short-acting types clear in 1-4 days. The laboratory measures secobarbital at 100 ng/mL.
How the Testr drug test screens for it
This panel is part of every Testr drug test. A certified collector handles the urine collection at your home, checks specimen temperature, and reads a clinical 14-panel drug screen cassette on the spot. For measured levels rather than a positive/negative read, add laboratory confirmation: a CAP-accredited lab quantifies the result by LC-MS/MS, with measured levels on the report. Testr covers the Los Angeles area seven days a week, 7 AM to 7 PM, with the earliest window 3 hours after you book.