What Material is Tested

Drug tests can use numerous different bodily materials. The reliability of these materials range from not at all reliable to excellent, depending on the type of test that is conducted. The most often used bodily materials are urine, blood, sweat, hair, breath and saliva. Evidence of drug use is often also assumed from specific behavior and psychological traits.

Metabolism and Metabolites

After someone has consumed a drug (either by smoking, swallowing, injecting or snorting it) the chemical is distributed through the blood. The blood then flows constantly through the person’s liver and other organs which causes the drug to encounter a series of enzyme systems. These enzymes convert the drug into several new products known as “metabolites” which make their way into different parts of the body, such as the hair, blood and urine. The metabolism of the drug taker determines the duration of this process within their body. The period of time that the metabolites remain in the body is known as “detection time”.


Most drug tests involve testing urine. This is because it is easy to get a urine sample and the analysis is fast and inexpensive. Urine tests reveal the existence of metabolites or other by-products in the subject’s system. The main problem with drug-tests using urine is that the results are considered to be proof that the subject was affected by drugs when the sample was taken. This is simply not true. A positive result can only be used to indicate that the subject had taken drugs recently. When the metabolites actually get into the urine, the subject is no longer under the influence of the drug and their functioning is not being affected at all. This is particularly obvious when it comes to marijuana. Marijuana can return positive results in urine tests more than three weeks after consumption.

Drug Urinalysis

Screening urine samples for drugs is the way that drugs and metabolites are detected in urine. The technology used for urinalysis can vary and can be individual designed to suit particular workplaces.

The primary disadvantage of testing urine for drugs is that they are not very specific, unless it involves a GC/MC test. This is a gas chromatography and mass spectrometry test. A urine test produces less accurate results than a blood drug test for determining the time that the drug was taken. The detection time can also vary considerably according to the individual. Test results can depend on many factors, such as diet, dosage and urine flow. Moreover, the dosages at which different people test positive can vary significantly.


The most common use of breath testing occurs when police test drivers for alcohol consumption. The advantage of breath testing is that it is cheap, non-invasive and produces instant results. Positive results to a breath test indicate that the blood contains a high percentage of alcohol, which means intoxication.

Motorists can now purchase disposable breath analyzers which they can use to test their own breath before driving. This involves exhaling into a cylinder that contains yellow crystals. If the crystals change to a blue-green color, it means that the person is over the legal limit and should not drive. There are several of these types of products which can be bought online by anyone.

In 1995-96 new alcohol testing rules came into effect and these meant that breath analysis became more common. Collections sites now commonly use “evidential breath testing” (EBT). This technology can only be operated by a technician with specific training, and the device itself costs from $2,000 to $8,000.


It has been presumed that a saliva drug test can show whether marijuana has been consumed recently. This is different to testing urine which can return positive test results if the subject has used marijuana anytime in the previous few weeks. Tetrahydrocannabinol (THC) is the main psychoactive component of marijuana. When this is administered intravenously it will not be obviously apparent in human saliva. This means that when cannabinoids do appear in saliva the marijuana has been smoked or ingested orally. Testing saliva is considered more accurate for finding evidence of recent marijuana consumption than urine testing. This is because drug test THC can be seen in the urine samples weeks after the marijuana has been consumed. It can be difficult to pass saliva drug test because the THC can be found within 10 hours of smoking a marijuana joint.


Drug-testing a blood sample measures within or not a drug or a metabolite is in the body at a particular time. These types of tests are considered to be the most accurate way of telling if a person is intoxicated. Blood drug tests are not used very often because they need specialized equipment and medically trained administers. These factors make it a more costly testing method.

Assume that you were part of an accident and you are confident that you had not consumed any drugs or alcohol. It is a good idea to suggest that you provide a blood sample in addition to your urine sample. That way, if your urine sample tests positive for drugs or alcohol, you can have the blood sample tested as evidence that you were not under the influence of drugs or alcohol when the accident occurred. One important point to note is that blood samples must be frozen to prevent drug metabolites from deteriorating.

Depending on how much marijuana was consumed, it can usually be detected in blood tests within six hours of consumption. After six hours has passed, the concentration of marijuana in the blood decreases significantly. It generally disappears completely after 22 hours.


Traces of drugs and drug metabolites can also be found in hair. When the drugs are consumed it is absorbed into the hair structure and stays there as the hair grows. After it has been absorbed in the hair sheath, it remains there as a record of the drug consumption. The drug metabolites find their way into the hair around one week after the consumption. The fact that hair typically grows at a rate of one-quarter to one-half of an inch per month, means that the hair can be seen as a time line of an individual’s drug use.

Research conducted by the National Institute of Justice Research found that testing hair for radioimmunoassay (known as RIAH) for low amounts of cocaine consumption revealed around 10 times more users than urine testing. Using the same testing for a moderate amount of cocaine use, found around 4 times more users than urinalysis. Hair analysis is not as accurate for picking up infrequent or single instances of drug use.

The Danger of Hair Testing

Drug-testing hair and urine relies upon the same technology; the only difference is the material that is being tested. The primary danger with hair testing is that it is much more threatening to an individual’s freedom than other methods of drug testing. This is because components of drugs remain in the user’s hair for longer durations. Evidence of drug use can be found in hair samples weeks or months after the drug was consumed. Blood or urine samples, on the other hand, only retain traces of heroin or cocaine for 2 or 3 days. Moreover, hair samples are much easier to obtain than urine or blood. Many of the privacy and invasive issues of collecting samples are eliminated with hair. The removal of this invasiveness means that hair testing is generally viewed more favorably by the judicial system.

The increased prevalence of drug testing in daily life has led people to develop ways to pass drug test. A rise in the use of hair tests means that the previous rules and strategies of drug testing will be changed. This is because testing hair expands the time frame in which illicit drug use can be detected. Whereas testing urine samples will only reveal evidence that drugs were used within the previous few days or weeks, testing hair samples can reveal drugs that were consumed several months ago (depending on the length of the hair). This can have serious implications for people who don’t want to lose their jobs because of recreational drug use. They can no longer abstain for a specific time period in order to be able to provide clean samples to pass drug test.

A further concern is the fact that hair samples are easy to manage and don’t require any specific storage conditions. Hair samples are able to be tested several times and it is relatively easy to collect several samples to compare. Also, unlike urine samples which can be manipulated in different ways, hair analysis is very difficult to foil. Hair analysis can even be done on samples from a deceased body many years after death. The same cannot be said for urine or blood tests. One famous example of this occurred when Dr. Ron Siegal from UCLA tested a hair sample from the nineteenth century poet John Keats. The results of these tests proved that Keats regularly smoked opium.

These factors can be it difficult to pass hair drug test. Whereas in the 1960’s the typical image of a pot-smoker was someone with long hair, the increased use of hair testing may mean that pot-smokers of the future will have shaved heads. As they search for new answers to the question of how to pass a hair drug test, they may also shave their legs, arms, chests, eyebrows and even pubic hair in order to remove all traces of drugs from their bodies! An important point to remember is that longer hair means a longer record of drug use. mbdetox.com contains a lot of additional information about hair drug tests.

Problems Involved in Testing Hair

One problem with the hair drug test is the fact that type of hair affects the rate at with the drug is absorbed into the strands. African-American hair, for example, absorbs drug metabolites 10 to 50 times more than Caucasian hair. These different absorption rates than have an impact upon drug test results. A further problem is the fact that contaminants in the air are also absorbed by hair. This means that exposure to marijuana smoke can cause the metabolites to be absorbed into the hair which can then lead to a positive drug test. This happens quite easily with marijuana smoke due to the fact that the fat soluble elements contained in THC bind readily with the human hair structure.

This means that if a friend smokes dope somewhere in your vicinity (particularly when this is in a confined area like a bedroom or car) the marijuana smoke will bind with your hair. You may then return a positive result to a hair test. Don’t forget, longer hair means a longer drug record.


Heroin and cocaine are particularly apparent in sweat samples. These drugs are usually tested using urine samples, but this method can only test for consumption in the previous 2 or 3 days as after that traces of the drugs disappear from urine. This means that continuous drug monitoring using urine would require screening to be carried out several times per week.

Drug metabolites can also be found in sweat which is excreted from the body. Small patches can be attached to the skin in order to collect sweat samples over a set period (from a few days to weeks). This type of swab drug test is currently being used to detect amphetamines, cocaine and opiates.

Using a sweat patch is an effective way of monitoring the possible drug use of people who are in a drug treatment program or under probationary court supervision. After the patch has been removed it is impossible to reattach. This prevents the device from being tampered with. Once removed, the patch itself can then be frozen up until the time it is tested. The method of drug testing is still being refined and further developed. Cutoff levels and assays are yet to be determined.

Still, this potential way of testing is quite daunting. It may be that one day people will be forced to wear a sweat patch while working so that possible drug use can be monitored on a continuous basis.