How Long is Urine Good for a Drug Test: Best Practices For Storing Urine

Daniel Miller
Daniel Miller, Ph.D Pharmacology, Drug Testing Specialist

Last updated on 2024 Jun 8

Room temperature: Urine can stay fresh for up to 4 hours at room temperature. After this period, it starts to degrade.

Refrigeration: I recommend storing a urine sample in the fridge if you need to preserve it overnight. It remains good for up to 24 hours. However, this method has its limits.

Freezing: Freezing urine can preserve it for up to 6 months. Keep in mind that freezing it for longer periods can alter its composition. I will explain how to store clean urine and keep it fresh for a drug test.

How long is urine good for at room temperature for a drug test?

According to Labpedia, urine can remain good at room temperature for up to 2 hours. Another study, published on PubMed, suggests it can last up to 4 hours. You can find these details here: Labpedia and PubMed.

If you are using someone else’s urine, ensure it doesn’t stay out for more than 2 hours at room temperature. Alternatively, synthetic urine can be a viable option, as it doesn’t have a time limit and remains usable as long as needed.

For those who need to keep a urine sample fresh overnight or for less than 24 hours, placing it in the fridge is a suitable option.

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How long can you keep a urine sample in the fridge?

If you need to preserve clean urine for a drug test, you can store it in the fridge overnight.

Theoretically, it can be kept in the fridge for up to a month because lab requirements state that urine is good for drug detection for that long. However, after a month, the lab might not detect drugs effectively.

The urine will change in composition over time, affecting the pH, creatinine, and specific gravity levels. Therefore, the best practice is to keep it in the fridge for no more than 24 hours. Make sure to use an airtight, sterile container to prevent contamination.

Also, consider the time needed to get to the drug testing facility so that the total time the urine spends at room temperature is less than 2 hours.

Later, I’ll explain how to recognize when urine is contaminated and cannot be used for a drug test.

Can you freeze urine?

The main goal when storing urine for a drug test is to prevent bacterial growth. You can safely freeze it and thaw it before a drug test. According to a PubMed article, urine samples can be safely frozen and thawed at least five times. You can read more about it here: PubMed.

Labs generally cannot tell if urine was frozen. In theory, they could use advanced techniques to analyze the urine composition and detect protein degradation, indicating that the urine is not fresh. However, such tests are costly, and pre-employment tests typically do not use them.

To store your clear urine in the fridge, use the proper container. It must be clean and appropriately sized. Drug tests require 1 to 1.5 ounces of urine, so a 2-ounce container is ideal. You can find more details here:

It’s best to use the bottle that you will use for your drug test, as transferring urine between containers increases the risk of contamination. Ideally, use special bottles with temperature strips on them.

bottle for storing urine in a fridge or freezer

These bottles are available on Amazon and are excellent because you can easily check the urine temperature before submitting it. They are also discreet, allowing you to sneak them into the crotch area.

So, put this bottle in the freezer, and you can keep it there for up to 1 year.

How to thaw frozen urine for a drug test

One method is to place it in a bowl of warm water. The water should be at body temperature to avoid overheating the urine. If the urine overheats, bacteria may grow quickly, ruining the sample.

Another method is to thaw it in the microwave. Since microwave strengths vary, it’s challenging to provide a one-size-fits-all approach. I suggest using 5-10 second intervals in the microwave and checking the urine’s condition after each interval. If you are using a bottle with a temperature strip, you will clearly see when the urine temperature is normal.

Below is a photo showing how long to microwave urine to thaw it. Two minutes were sufficient to thaw the urine. After that, the urine feels slightly warm, indicating that it’s close to body temperature. At this point, you need to be careful not to overheat it.

frozen urine in microwave

If you accidentally overheat the urine, just let it sit for a few minutes. The temperature will drop, and you can safely use it.

How to notice spoiled urine

Here, I’ll show you the signs of spoiled urine. Remember, a drug test collector will visually inspect the urine sample. If they notice that the urine is spoiled, you’ll have to resubmit the sample under direct observation. This means someone will watch as the urine comes out of your body, making it impossible to fake the test. If you see any of these signs in your urine, you’ll need another sample.

Unusual color: Fresh urine typically ranges from pale yellow to amber, depending on hydration. If the urine is clear, it might be too diluted. Dark yellow or other unusual colors might suggest contamination or degradation.

Odor: Fresh urine has a mild odor that intensifies and becomes more ammonia-like as it ages, due to bacterial growth. A very strong or unusual smell could indicate contamination or storage issues.

Turbidity: Urine should generally be clear. If it’s cloudy, this could mean it contains substances that shouldn’t be there, like bacteria or sediment, suggesting it may be spoiled.

And remember, if the outcome of the drug test is crucial, such as for a dream job, it’s better to err on the side of caution. Consider using high-quality synthetic urine.

This type of urine won’t spoil, and the best synthetic urine kits include everything you need to pass a drug test smoothly—discreet methods to carry the urine, reliable ways to keep urine warm, and high-quality urine that will pass all tests.

Here’s a link to a guide on the best synthetic urines: We Reviewed The Top Fake Urine Options For Passing A Drug Test In 2024

Storing a urine sample

If you’re unable to deliver your urine sample within an hour, it should be placed in a sealed plastic bag and refrigerated at approximately 4C. Avoid storing it for more than 24 hours.

The growth of bacteria in the sample can occur if not refrigerated, potentially altering the test outcomes.

Certain sample containers come with a preservative that allows the urine to be kept at room temperature for an extended period. Instructions on how to properly store your urine sample should be provided if immediate submission isn’t possible.