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.
Drug screenings most often test your body for meth by examining your urine or your hair. A blood test can also detect meth.
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.
If you only used meth once, a urine test can detect meth or its metabolites for about a few daysTrusted Source.
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.
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%Trusted Source 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.
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:
- It prompts your body to produce more urine, allowing you to expel more meth and meth byproducts.
- 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:
- muscle weakness or cramps
- nausea or vomiting
- drowsiness and lethargy