There are a few common ways to test for drug use. Generally, it entails getting a DNA sample through a sample of your urine, saliva, hair, or blood. These are the most common ways which are handled depending on the drugs tested and on the addicts themselves. Let’s see how these tests are being done.
This is the most common drug test and the most reliable one. On these tests, even a person who has never taken drugs can be positive. How is that possible? Well, some medications and herbal remedies can be mistaken for real drugs of abuse. So, before the testing starts, a person has to handle the list of all the medications and remedies previously taken. Most urine tests detect the following drugs:
- Phencyclidine (PCP)
The most important thing a laboratory person has to know here is how long drugs remain in a human body. A few factors can influence the concentration of drugs in our system: our metabolism, a number of drugs taken, hydration levels, and our overall health. Generally, drugs remain in our system as follows:
- Heroin – for 2 days
- Amphetamine – for 2 days
- Benzodiazepines – for 3 days for therapeutic dose or 4-6 weeks for habitual use
- Barbiturates – for 2 days to 3 weeks
- Ecstasy – for 2 days
- Cocaine – for 4 days
- Methamphetamine – for 2 days
- PCP – for 8-14 days (single use); or for 30 days (chronic users)
- Marijuana – for 2-7 days (single use); or for 1-2 months (habitual use)
- Morphine – for 2 days
These numbers don’t only show the presence of the drug itself in a human body, but also of their metabolites – substances which appear during drug’s decomposition. In today’s medicine the urine samples are also being tested for the masking substances which addicts can use when they want to fake a test, but in these cases, when these masking substances were used, the sample becomes automatically positive. Also, when a person tries to dilute the sample, the drug testing laboratories can detect the dilution from the start.
Hair drug testing can identify the drugs someone has used in the previous few months. This is actually a more accurate test for long-term drug users than urine or blood tests are. It is taken on 50-80 strands of hair cut from the back of the head. On these tests, a single or minor drug user will probably not be detected, so these tests are not done in these cases. If a person has only smoked a joint in the past 3 months, he will pass this drug test and the laboratory people know that. On the other hand, if a person has smoked a joint every day for a week, this will be detected.
Some other thing laboratory people know about this test is that if a drug hasn’t been used 90 days before this test is taken, the results will be useless. But generally, chronic users wouldn’t be able to avoid the drug usage for so long. Additionally, there are studies which show that cosmetically treated hair can fool this test for cocaine. That is why this test is taken when a person hasn’t dyed his hair for less than a month. If he dyes his hair regardless, he will be suspicious from the start.
This drug test can generally detect drug usage during the previous few hours or days. They can find any drug that can be found through the blood analysis. Most of the occasional drug users could pass this saliva test, so they are combined with the other two kinds of tests. These are the drug detection times for this test which laboratory people have in mind when testing:
- Opiates: From the point of ingestion up to 2 to 3 days.
- Marijuana and hashish (THC): From one hour after ingestion, and up to 24 hours.
- Benzodiazepines: From the point of ingestion up to 2 to 3 days
- Cocaine: From the point of ingestion up to 2 to 3 days.
- Methamphetamine and ecstasy: From the point of ingestion up to 2 to 3 days.
This is the most expensive and the longest method for drug testing. It is done by taking samples of your blood and it is not always relevant. This test only identifies if a drug is present in your system at the moment when the sample is taken, unlike urine test which detects even the metabolites of the drug indigested. So, it is relatively easy to fake the blood results and laboratory people know this. That is why they combine it with a urine test.