Soma Half-Life: Will Carisoprodol Show Up On Drug Test?

Last Updated: December 19, 2019

Authored by Roger Weiss, MD

Many employees require an pre-employment drug test, so worrying that Soma will come up in such a test is perfectly normal. What is Soma? Knowing it and how long this drug stays in the system is crucial in avoiding possible misunderstandings related to a drug test.

How Long Does Soma Stay In The System?

This question depends on several factors, such as the dosage administered. Doctors recommend doses of Soma 350mg or 250 mg two or three times per day for no longer than three weeks due to its risk of abuse and dependence.

Blood test

How long does Soma stay in the blood? Carisoprodol could show up in a blood test for about 24 hours after a single dose. If the blood sample is collected up to a maximum of 4 hours after ingestion of Soma, it can be determined the amount of the drug that was taken. It is worth mentioning that the blood test might not be accurate if it’s taken a full day after Soma ingestion.

Urine test

How long is Soma detectable in urine? In a urine test, the drug shows up for 2-3 days after a single dose and for longer in chronic users. For some individuals, the carisoprodol level might be more prominent, while at others the meprobamate metabolites can appear in higher concentrations depending on the person’s metabolism.

Saliva test

The saliva test shows Carisoprodol up to 4 hours after administration.

Because this test is efficient for a short-duration after the drug is ingested, it is usually applied when an intoxicated individual is refusing to take the urine or blood test.

Hair test

Carisoprodol can be detected in a hair test up to a month after the last dose. There is a drawback to this test; it will take longer for Soma metabolites to appear on the hair follicle after ingestion. This means that if an individual used Carisoprodol recently, the urine test would be more efficient to detect the drug, but if it was ingested within the past three days, then the hair test would be valuable.

Half-Life of Soma

The half-life varies between 1 and 3 hours, so it will take around 11 hours to eliminate a dose of this drug.

The drug’s metabolites, such as Meprobamate, will take longer to be excluded from the system. Therefore, it will take almost four days to get rid of these metabolites, even after eliminating the parent drug.

soma pills and alarm clock

Soma (Carisoprodol): Absorption, Metabolism, Excretion

With the standard prescription of 250 mg and 350 mg, the absorption time of Soma is 30 minutes. The drug’s effects will last between 4 and 6 hours. The drug is widely distributed in the system, and it is metabolized in the liver.

Carisoprodol is excreted in urine under the form of metabolites, and only 1% of the drug will be excreted unchanged.

Will Soma Show Up On a Standard Pre-Employment Drug Test?

Does Soma show up on drug test? Carisoprodol is not included in a pre-employment drug test and on the SAMHSA-5 screening. The drug will only be detected if the employer asks explicitly for Carisoprodol to be included in the panel.

Is Baclofen like Soma in this case? The same applies to Baclofen, a muscle relaxant similar to Carisoprodol.

False Positive Test With Soma

Although Soma drug class is a skeletal muscle relaxant, it is the Soma metabolites the ones that might cause a false positive test. The effects of meprobamate, the primary metabolite of Carisoprodol, are similar to barbiturates when it comes to how they affect the body and brain.

Meprobamate was a sedative-hypnotic frequently used for the treatment of anxiety. This happened before it was classified as a schedule IV controlled substance by the FDA. Meprobamate might lead to a false positive test.

Who May Be Tested For Soma

Employers do not usually test carisoprodol, and the drug is not part of the SAMHSA-5 screening. But even if Carisoprodol is rarely assessed in a standardized drug panel, there are some situations where individuals are tested for this drug.

Military members

Some military members have to operate heavy machinery and are frequently involved in missions where they need an optimal cognitive function, alertness, and vigilance. 

Drug rehabilitation members

Rehab patients are usually subject to extensive drug tests. Even though Soma is not labeled as a significant drug abuse such as amphetamines or opioids, it is frequently abused. That is why if an individual in rehab has used or abused CNS depressants, Soma drug tests are necessary.


Because Carisoprodol has similar effects with benzodiazepines, criminals might use this for intoxication, as a date rape drug or for other illicit means. That is why if an individual is considered a suspect in a case or a criminal, the Soma drug testing will be conducted along with the potential victim.

A certain category of employees

Employees who have to operate machinery, heavy-duty equipment or motor vehicles, such as machine operators, bus drivers, pilots or truck drivers, might be subject to extensive drug testing. Employees who are under the effect of Soma are prone to injuring themselves and others or damaging equipment.

truck driver standing near his truck

Because the side effects of soma muscle relaxer include tremor, dizziness, drowsiness, and blurred vision, it has been included among the ten most common drugs associated with DUI. That is why drivers might be tested to see if their driving impaired is caused by Carisoprodol high.

Although Meprobamate is a controlled substance at the federal level, Carisoprodol is not. That is why anyone can purchase this drug online, and soma 50 mg street value is accessible to everybody. For only fifty cents per pill, anyone can acquire unlimited quantities of Carisoprodol.

Factors That Affect How Long Soma Will Stay In The System

Although the half-life of soma can be approximated, the estimated time on how long it stays in the body varies from individual to individual and depends on some factors. Several variables can influence the time this drug stays in the system, such as:

  • Dosage
  • How the drug was used
  • Quality of the drug
  • Frequency of administration
  • Co-administered drugs
  • Metabolism rate
  • Age
  • Body mass and weight
  • Food intake
  • Water amount in the body
  • Liver and kidney health

How To Remove Soma From The System Faster

Does Soma show up on drug tests for a long time after the last use? It is worth mentioning that there are ways to remove Carisoprodol from the system faster. These should be tried only after asking a doctor about their safety and efficacy.


Individuals with a high body mass index could eliminate Soma faster from the organism with an activity aimed at burning fat.


Hydration speeds up the clearance of drugs through urine. It should be noted that a proper level of hydration has to be maintained and that drinking too much water at once can do more harm than good.

Calcium D Glucarate

Calcium D Glucarate is a supplement known to clear out the detoxification pathways in the kidneys. Most of Carisoprodol metabolites are excreted by the kidneys and cleared through urine.

Activated charcoal

This supplement binds toxins and the remnants of Soma from the gastrointestinal act, cleaning the body.

Note that these options should be previously discussed with a medical professional. Do not hesitate to ask for help if suspecting drug abuse in a loved one. Treatment of substance addiction is a long but manageable process.

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Published on: June 7th, 2019

Updated on: December 19th, 2019

About Author

Roger Weiss, MD

Dr. Roger Weiss is a practicing mental health specialist at the hospital. Dr. Weiss combines his clinical practice and medical writing career since 2009. Apart from these activities, Dr. Weiss also delivers lectures for youth, former addicts, and everyone interested in topics such as substance abuse and treatment.


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