Skip to main content

Many employers are turning to drug testing as an effective way of preventing drug use in the workplace. Drug abuse has long been a problem in many workplace settings in the U.S, and the numbers are staggering. According to the National Council on Alcoholism and Drug Dependence, about 14.8 million Americans use illegal drugs and about 70% are employees. Because of this, many companies test their workers for drugs at least once per year, with many more implementing random tests when they suspect someone may be using illegal substances.

Companies can use instant or home drug test kits, with remote workers for instance, to help detect the usage of commonly abused drugs like marijuana, amphetamines or cocaine, among other things. They are fast and easy to use. With these kits, you will only need to provide a urine or saliva sample and get the results within minutes. But there’s one problem: how do you know if the urine sample is not diluted in a home drug test? To mask positive results, urine samples can be adulterated with other substances or by ‘diluting’ it on urine drug testing.


What can cause a urine sample to be diluted?

There are many possible reasons for a urine sample to be diluted. It can even happen accidentally even if the person is not trying to cheat on their drug test. Here are some possible causes of a diluted urine sample.

Drinking lots of water.

Drinking lots of water is important to stay hydrated, but it can be a factor in the dilution of a urine sample. If a person has consumed large amounts of fluid before a drug test, there is a possibility that the urine can get diluted. 

Taking diuretics.

Diuretics are substances taken to increase the amount of urine passed by the body. Drinks like coffee and tea are diuretics and may lead your urine sample to be diluted. For this reason, it is important to restrict too much consumption of these drinks before a drug test. Additionally, some prescription medicines also have a diuretic effect which can also result in diluted urine.

Kidney problems

If a person has kidney problems, the sample may be diluted because of leakage or inability to concentrate urine. If your kidneys are not working properly, they may release too much water which can dilute the urine.


How can you detect diluted drug tests?

Luckily, there is a way for testers to determine if the urine sample is diluted. Most of the time, diluted urine has a lighter color than normal. Testers can also refer to validity checks such as the urine specific gravity and urine creatinine.

The normal range of creatinine concentration in your urine should be between 20 and 400 milligrams per deciliter. If the creatinine level found in a urine sample is only between 2 and 20 mg/dL, then the urine sample is diluted.

Additionally, normal urine has a specific gravity of between 1.002 and 1.030. Diluted urine will only have a specific gravity of between 1.001 and 1.003.


How can you ensure accuracy and prevent cheating on instant or home drug tests?

A drug-free workplace can be achieved by setting up proper guidelines for everyone to follow. Employers will need their HR managers to draft and implement a drug-free policy that includes guidelines that will prevent the adulteration of urine samples.


Here are five proven strategies you can take to prevent cheating on instant or home drug tests.

Enforce a random drug testing policy.

Employers should make it clear that they will enforce and have a random drug testing policy in the workplace. This way, employees won’t get too much notice of the testing beforehand. For a casual drug user, time can be his or her friend. So when you hand out the drug tests randomly and unannounced to everyone in the workplace, you can prevent cheating and ensure more accurate results.

Try using alternative testing methods.

Companies should consider using alternative drug testing methods. It’s important to include this in your policy and guidelines so you have an option to select another method if one is not effective in your workplace. The best thing about home drug tests is that they are not limited to one method. There are also home drug test kits that can test oral fluid instead of urine and it provides the same accuracy. Employers can include alternative testing methods in their drug policy guidelines to ensure no employee can cheat on it.

Consider setting up an on-site collection.

Doing the drug testing on-site can prevent adulteration of samples since you can enforce rules rather than sending them to another testing area. Employers can still collect samples on-site in home drug tests. Consider using a supervisor to collect samples. Once the employee provides the sample, you can immediately get the results within minutes.

Monitor the check-in time on site.

Be sure to check how long it takes for an employee to show up once you send them to take the drug test. Did the employee go straight away to the collection area or had reluctance and showed up hours later? There are many ways to cheat a drug test and a long delay can buy them time to dilute their urine sample. Employers can also monitor the time spent when collecting the sample. For instance, collecting a urine sample can be done in minutes or even a few seconds. A long delay can be a cause of suspicion.

Collect the urine sample early in the morning.

Drug levels in urine are at their highest in the early morning because the bladder is reliably full, and urine is most concentrated. This makes it the best time to collect a urine sample for a urine drug test.



As with most things, proper guidelines and preparation is the key to effective enforcement of drug testing in the workplace. Know that ‘cheating’ can happen anywhere especially when it comes to drug testing. However, having a solid guideline can give employers an upper hand. To ensure accurate and reliable instant or home drug test results, make sure to get your drug testing kits from a trusted provider like

Drug Testing

Author Drug Testing

More posts by Drug Testing