Do You Suspect You Got A ‘False Positive’ Result For Meth? Here’s What To Do

The use of meth has become so rampart that nowadays employers are not hesitating to ask their employees or employees-to-be for drug tests. If you ever found yourself at the tail end of getting a drug test, that must have knocked the socks off you! And you’d not be alone, as many just like you probably had just as many questions as you, going through their minds about these drug tests and what they entail. This is especially true of patients who receive drug & alcohol addiction treatment at a drug rehab Orange County.

You’ve also probably heard professional athletes decry false positive when they test positive for doping or other drug tests. This line of defense may seem desperate, but false positives do actually occur in these drug screening tests.

Accuracy during these drug screenings is of utmost importance as negative results can adversely affect lives, families, career, friendships and quality of life. Hence people are justified to be a little wary during these drug tests should a false positive result arise.

Now more than ever we are witnessing an increase in random workplace drug screening, onsite and home-testing kits hence the need for drug tests to be accurate. A false positive may cost someone their job, limit their movement and privileges through probation or worse still, it may land an innocent person in jail. We’ve witnessed professional sportsmen and women being excluded from competing as a result false positives. Then there’s the blaring danger of receiving wrong medical attention for a non-existent condition.

Meth is no different and just like many other drugs; it is possible to receive a false positive result during a drug screening. If yours happens to turns out positive, just remember to ask for a further confirmatory test known as GC/MS from the lab that did your test. We will look at GC/MS tests later, but first let’s delve into meth, screening and its implications during drug testing.

What is Meth?

Meth is short for methamphetamine and it just one of the many versions the drug methamphetamine. It is a white crystalline drug with the same addictive and potent quality as cocaine and other powerful street drugs. It is known by many names: crank, ice, chalk, glass and so on.

Methamphetamine overstimulates the central nervous system giving users a heightened sense of productivity, alertness and energy. Stimulants like amphetamine and methamphetamine give users an elevated sense of euphoria, but also delusions, hallucinations and cause overwhelming agitation. They develop paranoia and become physically aggressive. Persons using these stimulants are easily provoked and easily result to violence.


While Methamphetamine is banned in most countries globally owing to its classification as a schedule II drug, meaning it has absolutely no benefit to man, it is prevalent in the US, Oceania and some Asian countries. In the US, doctors sometimes prescribe low doses of Methamphetamine to patients to clear nasal congestion and sometimes to persons with attention-deficit disorder (ADD) and attention-deficit/hyperactivity disorder (ADHD).

Healthcare providers sometimes use Amphetamine to treat narcolepsy – a sleep disorder characterized by falling into a sudden deep anytime, and in the most inappropriate places. They also use it to treat patients with depression.

However, majority of Meth users use it for recreational purposes, to increase their productivity and just achieve that high. People take it by snorting it, injecting it, smoking it, or ingesting it. Whichever the method used to consume Meth, it will gives it users a serious dependency to it due to its ability to create a false sense of euphoria. Users say they experience a gush of happiness unlike any they’ve ever felt before. They have renewed confidence; they feel invigorated, alive and alert. And these effects can last between six to twenty-four hours. Meth is taken by people of all walks of life, but you will mostly find it rave parties or night clubs to keep the party going.


Crystal meth is highly addictive and just the first use gets people hooked for years. It is very concentrated, and though it gives people an unimaginable pleasure, they begin their downward spiral in life. Many users have reported getting addicted the very first time they used it. And as with other drugs Meth gives its users that that first feeling of euphoria, but begins to systematically alter their brain and bodily functions until they are no longer in control.

It is a dangerous and potent poison that first acts as a stimulant then begins to destroy the body. People addicted to Meth have debilitating health conditions, including brain damage resulting in memory loss, psychotic behaviour, aggression and acute heart conditions. Meth also uses up the body’s resources, creating a severe dependency on the drug.

Abusing these stimulants can also cause other serious health complications like, convulsions, severe tooth decay, heart diseases and even stroke.

Unfortunately, Meth happens to be one of the hardest drug addictions to treat and as a result many have died unable to wiggle themselves out of its potent clasp.

Why Do A Drug Test For Meth?

Employers use drug tests to make hiring decisions. You may need to be tested for meth and other drugs if your new job requires it. Also, even if you don’t use amphetamines, you may still be required to take the amphetamine test as a condition for continued employment.

People in professional sports may are also be subjected to random drug tests every once in a while to keep them on the right track, or qualify them to join a team.

Federal employees are also required to take mandatory drug tests. Federal authorities raised the required concentration for some drugs including morphine, methamphetamine among others to reduce the number of false positives.

Probation and parole officers administer drug tests to monitor whether someone being treated for drug use or a parolee is complying with the conditions of their probation and parole.

Court systems often require these tests to be conducted on recovering drug users, and parolees during their day in court.

Alcohol and drug abuse treatment programs conduct mandatory tests to evaluate the compliance of their patients and their adherence to the treatment plan. Indeed, a drug test is the first step to helping a meth addict on the recovery path.

Healthcare providers order drug tests for patients exhibiting symptoms of Amphetamine overdose such as psychosis and severe agitation. These tests include an ECG, acetaminophen test, and finger stick blood sugar test.

However, in as much as fast, inexpensive drug tests for meth are admissible, whether for personal or professional reasons, including home-based tests; tests that are not positive are still considered inadequate. This also applies to professional amphetamine screening.

Amphetamine Screening: What is this test?

Meth drug testing involves a biotic testing of specimen from a person’s body to detect if they have traces of methamphetamine metabolites. The following samples can be used for testing:

  • Urine
  • Blood
  • Saliva
  • Hair Follicle

Amphetamine, methamphetamine or meth is a central nervous system stimulant. These tests are able to reveal just how much this group of drugs are in a person’s blood.

This test can also differentiate between recreational use and prescription use.

Meth Detection Period

Meth detection period refers to the time it takes for the drug to be detected when a drug test is administered on a biological specimen. This period is usually dictated by factors such as the amount of meth ingested, the frequency, the class of the drug, the age of the user and their overall health.

For instance, a urine methamphetamine drug test will take between 3 to 5 days to be detected. Blood and saliva methamphetamine screening will be detected within 12 hours of use. Hair follicle test of the same methamphetamine takes longer, even up to 90 days to be detected.

What Drugs Are Tested?

The following five categories of drugs are usually tested, as is also mandated by the Federal workplace guidelines.

  • Phencyclidine (PCP)
  • Amphetamines/Methamphetamine
  • Opiates/Heroin
  • Marijuana/THC/Cannabinoids
  • Cocaine

Other categories according to SAMHSA guidelines may include:

  • Prescription opiates such as oxycodone, hydrocodone and methadone
  • Designer drugs like Ecstasy (MDMA), Bath Salts or Spice.
  • Barbiturates
  • Alcohol (Ethanol)
  • Benzodiazepines, like Xanax (alprazolam) or Valium (diazepam)

Meth Screening: Types Of Meth Drug Tests And Screens

Meth drug tests and screening are done on the blood, urine, sweat, hair, and saliva. Each is unique, and offers different information about the drugs in use. Experts are able to draw parallels, distinguish weakness and strengths and derive relationships between people’s reaction to certain drugs.

The following are the various types of drug screens for methamphetamine:

Meth Blood Test: These tests require blood to be drawn from the vein using a needle. They are the most accurate. Apart from the negligible bruising and discomfort where the needle pricked, this method poses no danger at all. This type of testing is able to connect drug concentrations to behavior change. However, it is limited to recent usage only and does not necessarily paint an accurate picture of past drug use.

Hair tests– These tests take longer, up to 90 days since use. However, they provide a historical insight of the drug use. Its only limitation is waiting for hair to actually grow so that hair can be collected for sampling –that takes roughly a month to achieve about one-half inch of hair growth.

Saliva testing– Saliva drug tests are particularly useful at home and are not as invasive as urine or blood. In just 5 minutes, one can get the results and they are usually very accurate. This is because with saliva you actually see traces of the drug itself rather than meth metabolites that are tested in the urine.

Urine testing– Again this tests is quite straightforward. You put your urine in a special cup for drug testing and present it to the concerned professional to test it. Usually, Meth metabolites can be detected several days from use.

Each test really depends on the individual. It is important to know that tests need to be as accurate as a possible, especially if you are planning to administer the test yourself. Parents/guardians can test their kids at home. However, should you seek the services of a professional ensure that they have the proper paperwork and experience.

Meth Cut-Off Levels

In a lab your tests can be affected by many factors including the methodology used to get the drug test results. However, just because a test shows you have a small amount of amphetamine concentrations should not be cause for alarm. But if on the other hand, your tests results show you have huge amounts of the drug coursing through your veins that may be potentially fatal to you and something has to be done before it gets out of hand. The following are the typically ranges used in blood tests:

  • Amphetamine Levels of within the range 0.02 to 0.05 milligrams/liter (mg/L) is considered therapeutic, or prescribed use.
  • Amphetamine Levels greater than 0.2 mg/L is likely a sign of use.
  • Amphetamine Levels greater than 2.5 mg/L are considered toxic and possibly lethal.
  • Methamphetamine levels greater than 300 ng/ which is the cut off level for hair meth is considered toxic and possibly lethal.
  • Methamphetamine levels greater than 50 ng/ml which is the cut off level for Saliva meth is considered toxic.
  • Methamphetamine levels greater than 500 ng/ml in initial test urine is considered toxic. The cut-off for confirmatory test, done through mass spectrometry and chromatography, is 250 ng/ml.

These test results only indicate the amount of Methamphetamine in your system at the time of testing. Healthcare providers diagnose amphetamine use in their patients only after conducting a physical examination on them. They also record their medical history.

Positive Drug Testing For Meth

Urinalysis is usually conducted for most meth drug testing. Tests indicate positive within 1-4 days of use, and in cases of heavy usage even up to a week.

The method of ingestion also determines how long and in which state meth stays in the urine. When meth is ingested about 30-54 percent is shed into the urine as methamphetamine, and 10-23 percent as amphetamine. When Meth is taken intravenously, 45 percent ends up being expelled in the urine as methamphetamine, while 7 percent is expelled as amphetamine.

Some False Positives For Meth Drug Test

What Might Affect Your Test Results?

For one, the method used to administer the drug test may increase/decrease the chances of a false positive owing to their accuracy.

Blood tests for amphetamines are generally more accurate compared to their urine counterpart. Blood tests also cost more, but they are worth the investment. Urine tests can easily be altered just by adding a substance to it, so there is a risk factor.

Remember, any positive drug test should always be followed up with a secondary test such as the Gas Chromatography Mass Spectrometry (GC/MS). This particular test identifies specific substances and levels of a specific compound in the test.

When preliminary drugs screening tests also called immunoassays are done, if the result is positive, then a second confirmatory can be requested. This is usually done on positive results only and in this way, it greatly reduces the possibilities of false positives results to zero. But, GS/MS can also produce false negatives.

The benefit of the immunoassay is that large scale screenings can be done, and the costs are minimal. This allows the tester to split the test samples into two, where the second batch of samples are kept aside for confirmatory testing, in case the first samples returns a positive result.

In this way the GC/MS becomes the gold-standard since it is the test that confirms or denies the immunoassay.

Rare cases emerge where the immunoassay may produce positive results for illicit or prescription drugs even though the subject has not used the said drugs. Bearing in mind that tests cannot be 100% accurate, all the time, it is important to give a full disclosure of your prescription history to the relevant authority, frequency, including any over the Counter Drugs as well as supplements or herbal drugs taken prior to taking the drug test.

Usually, no prior preparation is needed before taking a Meth drug test. However, it is important to be aware of the common medications, both over-the-counter (OTC) and prescription that could potentially give you false positive results.

These classes of drugs will give a false positive for meth on a drug test.

  • Decongestants
  • Antihistamines
  • Antibiotics
  • Analgesics
  • Antidepressants
  • Antipsychotics
  • Some OTC products

Bupropion (Wellbutrin): it is used as an antidepressant, helps in quitting smoking and for weight loss. However, bupropion may give a false positive test result for methamphetamine, amphetamine, and even LSD.

Fluoxetine (Prozac) and trazodone: These two drugs are used to treat depression. However, if one has taken any of them before a drug test is administered to them, it may give them a false positive result for methamphetamine, amphetamine, and even LSD.

Metformin (Glucophage): This an effective drug for managing diabetes. Ingesting Metformin may result in a positive test for methamphetamine or amphetamine.

Pseudoephedrine (Sudafed): This drug is used for sinus and as nasal decongestant. Sudafed however may result in a positive test for amphetamine or methamphetamine.

Methylphenidate (Ritalin): This suppressant is used for the treatment of ADHD. Ritalin is however well-known for giving false positive test results for methamphetamine, amphetamine, and even LSD.

Labetalol (Trandate): As an alpha and beta blocker, this drug is very effective for controlling blood pressure. However, if one has taken labetalol, it may give a false positive result for methamphetamine, amphetamine, and even LSD.

Further, upon the initial testing based on immunoassay, these substances reportedly gave a false-positive urine result.

Listed below are drugs containing elements that will give a false positive result during meth drug test.

  • Trazodone(Desyrel): gave a false positive result for Amphetamines/methamphetamines1,7
  • Tramadol: gave a false positive result for Phencyclidine (PCP)1
  • Thioridazine (Thorazine): gave a false positive result for Methadone1,7, Phencyclidine (PCP)1
  • Desipramine, gave false positive result for Amphetamines1
  • Clomipramine, gave false positive result for Methadone7
  • Chlorpromazine (Thorazine), gave false positive result for Amphetamines/ methamphetamines7, Methadone7
  • Bupropion (Wellbutrin), gave false positive result for Amphetamines/ methamphetamines7
  • Brompheniramine , gave false positive result for Amphetamines/ methamphetamines3,7
  • Sertraline (Zoloft): gave false positive result for Phencyclidine (PCP)1,7
  • Selegiline (Eldepryl, Zelapar), gave false positive result for Amphetamines1,8
  • Ritodrine, gave false positive result for Amphetamines1
  • Ranitidine (Zantac), gave false positive result for Amphetamines/methamphetamines1,7
  • Quetiapine (Seroquel) , gave false positive result for Methadone7, Tricyclic antidepressants1
  • Pseudoephedrine, gave false positive result for Amphetamines1
  • Promethazine (Phenergan), gave false positive result for Amphetamines/ methamphetamines1,3,7
  • Phenylpropanolamine, gave false positive result for Amphetamines/ methamphetamines1,3,7
  • Benzphetamine (Didrex, Regimex), gave false positive result for Amphetamines1
  • Amantadine (Symmetrel), gave a false positive result for Amphetamines1
  • Verapamil (Calan), Methadone7, Other opiates1
  • Venlafaxine (Effexor), Phencyclidine (PCP)1,7
  • Trimipramine, gave false positive result for Amphetamines1
  • Trimethobenzamide (Tigan, Ticon, Benzacot), gave false positive result for Amphetamines1
  • Phentermine, gave false positive result for Amphetamines1
  • Methylphenidate, gave false positive result for Amphetamines1
  • MDMA, gave false positive result for Amphetamines1
  • Labetalol, gave false positive result for Amphetamines1
  • Ketamine, gave false positive result for Phencyclidine (PCP)1
  • Imipramine, gave false positive result for Phencyclidine (PCP)1
  • Ephedrine nasal inhaler, gave false positive result for Amphetamines/ methamphetamines1,3
  • Diphenhydramine, Doxylamine (antihistamines), gave false positive result for Methadone7, Opiates1, Phencyclidine (PCP)1, and Tricyclic antidepressants1
  • Diet pills, gave false positive result for Amphetamines3

In conclusion

We have seen that there is an increased demand for drug screening by employers. Courts, parole officers and health workers demand for meth drug tests, and indeed other drugs as well to ensure their former meth addicts stay in line. But we have seen that with more information about correct drug testing, more cases of false positives to Meth on drug test are emerging, genuine cases.

Employers and other stakeholders who demand drug tests need to be fashioned with accurate drug test of the concerned people.  A false positive can end up costing someone their family and friends; their career; limit their movement and privileges through probation; or worse land an innocent person in jail.

It is possible to receive a false positive result during a meth screening time. Should this happen to you, simply request for a further confirmatory test known as GC/MS (Gas Chromatography Mass Spectrometry) from the lab that did your test. This is the ‘gold-standard; test that confirms whether your initial test is actually a false positive, or not.