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Methamphetamine, or meth, is a stimulant that can energize both your body and mind. It poses a high risk of addiction.

Meth is known for giving people a “rush” or “high” of good feelings. This sensation only lasts a short while — often a few minutes — but the drug itself can stay in your body for a much longer period of time.

A urine test can detect traces of meth in your system within the first week after use. If you need a negative drug test for employment or legal reasons, you’ll want to avoid using meth during that time period, since there aren’t any guaranteed ways to make meth fully leave your system before the test.

Read on to learn how drug tests detect meth and how your body processes the drug.

Healthline does not endorse the use of any illegal substances, and we recognize abstaining from them is always the safest approach. However, we believe in providing accessible and accurate information to reduce the harm that can occur when using.

Drug screenings most often test your body for meth by examining your urine or your hair. A blood test can also detect meth.

Urine test

When meth enters your bloodstream, your body breaks the drug down into other, simpler chemicals called metabolites. Your body will absorb some of these chemicals, but most of the drug and its metabolites wind up in your kidneys to become part of your urine.

Anywhere from 37% to 54% of the meth you take will come out in your urine chemically unchanged.

If you only used meth once, a urine test can detect meth or its metabolites for about a few days.

But if you use meth regularly, some of it may remain circulating in your system, waiting until you release it as urine. You may need to wait up to about a week after using meth to get a negative urine test, though the exact amount of time this takes can vary.

Hair test

When you use meth, your bloodstream carries it to every part of your body, including the cells in your hair follicles. As your hair grows, your body pushes these cells out of your follicles. By the time you can see your hair, the cells have already died — but they’ve also become microscopic time capsules, trapping the meth they absorbed inside.

A hair follicle test can reliably detect meth and its metabolites for about 90 days (3 months) after you last used the drug. However, around 16% of people who use meth regularly will still have detectable meth in their hair after about 120 days (4 months). So, you may need to wait for several months to test negative for meth on a hair test.

If you need a negative test result, you might wonder what you can do to help meth leave your system faster.

The short answer is, not much.

Hydration

One strategy you may have come across involves drinking a lot of water at once — with “a lot” meaning two or three 12-ounce glasses.

Drinking a lot of water does two things:

  1. It prompts your body to produce more urine, allowing you to expel more meth and meth byproducts.
  2. It can dilute your urine 10-fold within 30 minutes, lowering the concentration of meth in your urine enough that you test negative.

Of course, this plan has one drawback: The screening will show that your urine has been diluted.

Your body produces the same amount of a chemical called creatine each day — under typical circumstances, that is. Diluted urine will have low levels of creatine. That said, other physical conditions can also affect your creatine levels, so testers typically can’t say for sure that you intentionally diluted your urine.

It’s also important to keep in mind that drinking very large amounts of water in a short period of time can cause water intoxication, which can be fatal. Drinking more than a liter (L) of water per hour for several hours is very dangerous.

You’ll want to get emergency medical attention if you’ve had more than 3 L of water in a few hours and experience:

  • headaches
  • muscle weakness or cramps
  • fainting
  • nausea or vomiting
  • drowsiness and lethargy
  • seizures

FYI: Drinking vinegar won’t help

You may have read or heard that drinking vinegar can help your system clear a substance within a day.

But vinegar won’t remove meth from your body — or give you a negative result.

Diuretics

Diuretics, or water pills, may also dilute your urine and help you pee more. But they also put more sodium in your urine, which may provide a pretty obvious sign that you intended to dilute your sample.

Shaving your head

A hair follicle test isn’t restricted to hair on your scalp — body hair can also work. So unless you remove every hair on your eyebrows, chin, armpits, chest, legs, and pubic area, you’ll still have detectable meth on your body.

What about bleaching your hair?

Bleaching your hair breaks down the chemicals inside, so technically it would remove meth from your system. But examiners may still be able to find chemicals in your hair that confirm a positive result.

So what’s going on in your body between the time you use meth and when you take the test?

No matter how you consume meth, whether by snorting, swallowing, or injection, it ends up in your bloodstream eventually. Your blood carries meth all over your body, but it deposits most of the drug in your brain, lungs, liver, and kidneys.

Meth that enters your brain drastically increases your dopamine levels, creating a powerful reward incentive to keep using. However, it can also kill brain cells, causing long-term damage to your memory, attention, and executive functioning.

Meth that doesn’t go to the brain will either leave your body in your urine or be gradually broken up into two components:

  • Amphetamine: Another stimulant that poses a high risk of addiction, amphetamine also raises your brain’s dopamine levels, though not as much as meth does.
  • Para-hydroxymethamphetamine (p-OHMA): This metabolite raises your blood pressure and boosts your adrenaline. It has little effect on your brain.

These metabolites will also eventually get washed out of your body via your urine.

Beyond a positive drug test, meth can affect your mind and body in many ways:

Short-term effects include:

Long-term effects include:

If you get a positive result after a drug screening, the examiners may encourage you to consider substance use treatment. They may refer you to a local program, but you can also ask a doctor or mental health professional for treatment recommendations.

You can also explore options for treatment programs in your area using the Substance Abuse and Mental Health Services Administration (SAMHSA) services locator.

The Food and Drug Administration (FDA) has not approved any drugs to treat meth addiction the way it has for opioid use disorder or alcohol use disorder. So, treatment for meth use may rely heavily on therapy.

Treatment goals of therapy may include:

  • building motivation to stop using meth, such as finding alternate hobbies
  • learning how distorted or distressing thought patterns can contribute to self-sabotaging behaviors
  • educating your family members on how meth addiction works and how they can support you
  • addressing underlying trauma or emotional pain that plays a part in meth use

Keep in mind, too, that addiction isn’t a choice you make. Meth use disorder and meth addiction are serious mental health conditions that often require professional treatment. There’s no shame in asking for help, and it’s never too late to reach out for support.

A urine test can detect meth use for roughly a week, while a hair test’s detection window is usually somewhere around 3 months. That said, the detection window may be longer if you use meth regularly.

If you’d like to stop using meth, support from a trained specialist can help you take the first steps toward recovery.


Emily Swaim is a freelance health writer and editor who specializes in psychology. She has a BA in English from Kenyon College and an MFA in writing from California College of the Arts. In 2021, she received her Board of Editors in Life Sciences (BELS) certification. You can find more of her work on GoodTherapy, Verywell, Investopedia, Vox, and Insider. Find her on Twitter and LinkedIn.