How To Avoid a “Negative Dilute” On Your Drug Test

When you have to take a drug test at work, it can be an extremely stressful process. Even if you have no reason to believe you’ll test positive, there are a number of different factors outside of your control that can affect the result. Worse yet, because certain industries have strict regulations that require these drug tests, your job could very likely depend on the result.

One of the most common results that come out of a drug test is a “negative dilute”, which occurs when the sample you provided doesn’t contain a high enough concentration of the drug being tested for. Depending on your employer’s policies and the circumstances surrounding the test, a negative dilute result may be treated as a failed drug test, which can have obvious negative effects on you and your family. Because the stakes can be so high with a drug test, it’s important to understand how these results happen and what to do to avoid them.

How Does a “Negative Dilute” Drug Test Result Happen?

There are a number of ways a “negative dilute” result can happen. Most often, they occur when the sample provided is diluted with water or some other liquid, either intentionally or unintentionally. Generally speaking, a “negative dilute” result most often occurs because of the following factors:

  • Over-hydration – One of the most common ways a negative dilute result happens is when you drink an excessive amount of water before the drug test. This can dilute the urine and lower the concentration of drugs or metabolites, resulting in a negative dilute drug test result.
  • Medications – Certain medications or medical conditions can cause an increase in urine output, leading to a dilute sample. For example, diuretics or water pills prescribed for high blood pressure or edema can cause dilution of urine.


  • Certain health conditions – Health conditions such as kidney disease or diabetes can affect the concentration of urine and lead to a negative dilute drug test result.


  • Laboratory error – Although rare, errors can occur during sample collection or analysis that can cause a false negative dilute result.


Usually, when a sample is diluted, it doesn’t provide a clear enough indication of the presence or absence of drugs. As a result, the drug testing laboratory will typically classify the result as “negative dilute.”

It’s important to note that while a negative dilute result does not necessarily mean that you have used drugs, it does raise suspicions and may require you to take another test. This can mean that you miss time at work, especially if your job is safety-specific or requires a negative drug test result as a condition of your employment. Thus, you should familiarize yourself with ways to avoid this result.

How To Avoid a “Negative Dilute” Result On Your Drug Test

Having to provide a urine sample for a drug test isn’t always easy. When you add the stress of your ability to work hinging on the result, it often makes providing a sample even more difficult. This can sometimes lead you to overprepare in terms of drinking water or, worse, trying to intentionally dilute your sample. Ultimately, your best option is to simply not use drugs and provide a clean, non-diluted sample. This is sometimes easier said than done, but there are a number of ways that you can avoid a “negative dilute” result on your drug test:

  • Drink normal amounts of water – Drinking too much water can dilute your urine, so avoid over-hydrating before your drug test.


  • Do not add water or other liquids to your urine sample – Adding water or other liquids to your urine sample can be detected by the laboratory and can lead to a failed drug test.


  • Provide a midstream urine sample – When providing a urine sample, start urinating in the toilet, then catch the midstream urine in the sample cup. This can help reduce the chance of dilution caused by urine in the bladder.


  • Avoid diuretics – If you are taking medications, check with your doctor to ensure that they will not cause dilution of urine. Avoid diuretics or water pills, as these can increase urine output and dilute your urine.


  • Avoid excessive sweating – Avoid activities that cause excessive sweating, such as strenuous exercise or sitting in a sauna, as this can cause dehydration and dilution of urine.


  • Follow instructions carefully – Follow the instructions provided by the drug testing facility carefully, including any specific instructions about diet or hydration.


Obviously, attempting to cheat a drug test by diluting your urine sample or taking other measures to mask the presence of drugs is illegal and can result in severe consequences, including loss of your job. Not only that, but it can lead to fines and legal action.

What Should I Do If My Test Results In a Negative Dilute?

There is any number of reasons that your drug test result comes back with a “negative dilute.” At the same time, no matter what the cause is, your employer likely has a policy that guides what will happen after this result. If this happens, you should take the following steps:

  • Speak with your employer or the entity that required the test
  • Retake the test
  • Provide a different type of sample
  • Discuss the possibility of a false negative
  • Follow any other instructions or policies

Although frustrating, having a “negative dilute” result on your drug test doesn’t necessarily mean that you’ve used drugs or intentionally diluted the test. However, it is possible for substances to be present in your system at levels that are below the test’s threshold. Thus, if your test result comes back with a “negative dilute”, it’s important to immediately seek guidance from your employer.

Fleet Drug Testing Has the Solutions You Need

Whether you’re an employee or employer, Fleet Drug Testing has the solutions you need to stay up-to-date and compliant with any rules and regulations. Our team of knowledgeable professionals provides a full range of services relating to DOT drug testing guidelines and can help make sure that the results you get are accurate and reliable. To learn more about our services, contact us today.

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