A urine drug test can identify drug use in the last few days, while a hair follicle drug test may detect drug usage in the last 90 days. This is important because even after you stop using drugs, traces of them may remain in your body for some time before they are completely removed.
Hair follicles are found inside each human being and grow at a consistent rate of about 1mm per month. By taking small samples of your hair over time, it is possible to estimate how long ago you stopped using drugs and how often you did so. A hair test can be used in place of a urine test to screen employees for drug use. The sample of hair must be from the same area of the head, so that variations in growth rates do not cause an false result.
Hair grows in three-month cycles, so to perform a reliable drug test, you need to take several samples over time. It is best if these samples are collected regularly, such as every three months. If you only collect one sample from someone, then that person will likely fail the test, because there's no way to know how much drug usage he or she had in between samples.
The most common form of drug testing is called a urinalysis (also referred to as a urine screen).
The only drug test that can identify recurrent drug use up to 90 days previous to the test is a hair follicle drug test. This is feasible because medications in the circulation become a component of hair cells as they develop. Thus, if drug use is prevalent within the past 90 days, the concentration of these medications in the hair will increase at a rate consistent with their current usage.
Some medication classes are more likely than others to be found in hair samples. These include antidepressants, anti-anxiety medications, beta-blockers, and opioid painkillers. Hair tests cannot distinguish between different medications from the same class. For example, someone taking both an antidepressant and an antianxiety medication would have both classes of drugs detected in her hair.
A hair sample can reveal whether you used marijuana recently. However, since marijuana becomes present in the body after use it cannot be used as evidence of recent drug activity.
Hair tests can also reveal whether you took which drugs at particular times during a given period. For example, if you wore jewelry made out of cocaine or heroin at some point during the last month, then those substances were in fact used by you during that time frame.
Because hair takes time to grow, a hair follicle test may not identify drug use a few days before the test if the subject is an occasional or first-time drug user. Employers must consider this while deciding on a drug testing procedure. However, this test may offer a respite for infrequent or one-time users. Subjects who use drugs but are clean when they go in for their job application may not be detected by this method.
Hair tests look for the presence of drugs in the bloodstream. As such, these tests can show whether someone has used drugs within the previous few months. They cannot show what type of drug was used or how recently it was used. To determine whether a person uses drugs regularly or frequently, employers may want to consider other methods of screening such as urine tests, saliva tests, and blood tests.
Occasional or one-time users can still perform jobs requiring only occasional contact with others. If a job requires constant contact with others, such as an office worker, then an occasional user will not be able to keep up with the demands of the job. Occasional users are likely to be fine working in jobs that do not require constant contact with others.
People who use drugs regularly or frequently need to be sure that they do not show up positive on a drug test. Such subjects should avoid jobs where a positive result would be detrimental to their employment prospects or cause them to be excluded from further participation in the company's drug program.
Hair samples can reveal a longer time of drug usage than other kinds of testing (urine, blood, and oral fluids). Urinalysis, for example, can identify most drugs only within 2-3 days of usage, with the exception of marijuana, which may be identified for a longer length of time. Blood tests can show whether someone has used drugs in recent history but cannot tell how long ago they were taken.
Drugs enter the body through pores in the skin called "gaps" in the nail bed where there are no nails. This is also where urine flows out of the body. Drugs can also enter through your mouth, nose, and lungs. They go into your bloodstream and are distributed by the protein molecules in blood cells called "globulin." The more sensitive your test, the longer you can be exposed to drugs without being detected.
Your body gets rid of drugs very quickly once they are no longer needed. It does this through metabolism in the liver and through the kidneys. Some drugs are removed from the body entirely in the feces while others are stored in the body's fat cells. If you have used drugs recently, a drug screen will show up positive.
In general, it takes about one month for all drugs to leave your system.
A hair drug test may identify drug usage how far back in time? Hair drug tests have the greatest detection time, detecting drug usage for up to 90 days. Depending on the medications used, a hair sample can sometimes be used to identify when drug usage began and whether it was ended. A hair sample can also reveal information about recent use of drugs not readily apparent from other testing methods.
Hair grows at a constant rate until it is cut or pulled out. Then growth stops until new growth appears. This means that if you stop using drugs, your hair will grow out of any medication that was in it at the time of stopping.
If you are seeking to enter a drug-free lifestyle, it is important to understand how long-term drug use affects your hair. Drug use can lead to hair loss and changes in hair texture, color, and structure. Also, certain medications can cause changes to the brain that affect how we perceive beauty and fashion, which can influence what kind of hairstyle will look good on us.
Studies show that hair follicles contain drug residues for up to 90 days after cessation of use. This means that if you stopped using drugs 90 days ago, then your hair would no longer contain those compounds.
90-day period Hair drug tests have the greatest detection time, detecting drug usage for up to 90 days. However, since drugs are not destroyed by sweating or bathing, a positive result may still be present even if the user stopped using them recently.
30-day period A study conducted by the National Institute on Drug Abuse found that drug testing results remain valid after 30 days if samples are stored at room temperature and not frozen. However, if a person goes without drugs for more than 30 days, their sample will no longer detect drugs used previously.
7-day period A study conducted by the University of Michigan Health System found that urine drug tests remain reliable even if users go without drinking for only one day. However, since sweat contains some of the same drugs found in urine, this means that drug tests based on sweat will also be accurate even if users stop drinking entirely for seven days.
The length of time that your drug test will show you tested positive for drugs varies depending on the type of test and the amount of medication in your system. Most drug tests can detect recent use of opioids, cocaine, marijuana, methamphetamines, hallucinogens, and other substances. Some tests can also detect exposure to pesticides, heavy metals, and solvents.