Strategy: Abstaining
Abstinence is a legal strategy for passing the drug test in which all prescriptions*, over-the-counter medicines, and recreational drugs are avoided prior to testing. The duration of abstinence--called the "detection time"--depends on how long certain drug metabolites can be detected by a urine test. For example, cocaine is usually undetectable after 3-5 days, whereas chronic marijuana use can be detectable for as long as 2 months. With this strategy foods with poppy or hemp seeds are avoided because they can cause positive tests for opium and marijuana. (*Prescription users should always check with their physicians before they stop using medication.)

Strategy: Flushing
You can pass the drug test by putting liquid through the urinary system washes drug metabolites out, which reduces the danger of testing positive. A problem is that after flushing urine is colorless, which can arouse suspicion. This can be solved by taking vitamin B, which turns urine dark yellow so that the sample appears normal again. Over-the-counter diuretics, available in drugstores, accelerate flushing by stepping up secretion of water from the body. Caffeine is a diuretic, so drinking coffee, black tea, and caffeinated cola--all of which are perfectly legal--helps flush the system. Flushing is legal, and, in fact, drinking a lot of fluids is recommended by nutritionists. Nonetheless, talking about beating the test by drinking water is not a good idea, because it can cause suspicion and lead to closer scrutiny with more sophisticated tests. Flushing can be detected by measuring the creatine and specific gravity of the urine. But these tests are expensive and rarely done.

Strategy: Masking
Masking is a strategy for passing the drug test in which a legal substance masks or covers the presence of drug metabolites in the urine so that they are not detected when the urine is tested. Antacids like Tums and Rolaids are thought to mask amphetamines, cocaine, and PCP. Aspirin and ibuprofen can sometimes hide cannaboids and opiates.

Strategy: Diluting
With the diluting strategy for passing the drug test, water is added directly into the urine sample, which dilutes the concentration of drug metabolites. This technique is effective but dangerous, and if caught, one can get into serious trouble. Under the stringent Federal Guidelines, blue dye is added to the toilet water and the back of the toilet is taped up to prevent diluting. Additionally, the temperature of the sample is recorded. On the other hand, many drug testing situations are not stringently monitored, making it easier to add water to the sample.

Strategy: Substituting
In substitution strategy for passing the drug test, the person does not provide any urine but pours someone else's urine into the specimen cup. This strategy is dangerous, because monitors are on the lookout. If substitution is suspected, there is a lot of explaining to do. In some states, tampering with a drug test is a misdemeanor. Aside from the challenge of successfully sneaking a fake sample into the test site, getting uncontaminated urine can be difficult. Supposedly "clean" urine may test positive for something the donor did not know would trigger the positive test. Some people have put the substitute sample into "bladder bags" strapped to the body, which keeps it warm and (hopefully) avoids detection during a "pat down."

Strategy: Adulterating
Another strategy for passing the drug test is adding a substance to the sample that nullifies the urine test. People have tried lye, salt, household ammonia, bleach, soap, and Liquid Drano. Each has problems and effectiveness is far from guaranteed. Table salt and soap are the most reliable. Salt can be carried into the test site under the fingernails. However, Federal Guidelines require that the hands be washed in the presence of a monitor for just this reason. In more casual testing settings, adulteration can be relatively easy. Tampering can be detected by testing the pH of the sample, but this is rarely done--except when suspicions have been aroused.

Strategy: Handling the Paperwork
Before you can be legally tested, you must complete and sign a Consent Form, which requires that you disclose all medications taken recently. The purpose of the disclosure is to provide an explanation if you test positive because of having consumed a food or legal medicine that tests like an illicit drug, called "cross-reacting." All positive results are supposed to be review by a Medical Review Officer (MRO), who decides if it is valid and reported as a positive, or if it is a "false positive," which is reported as a negative. Interviewing you and discussing the substances you disclosed is central to this decision. Refusing to sign the Consent Form or to take the test is not advised, because it brings suspicion regardless of your reasons for refusing. People who use drugs illicitly sometimes use the disclosure form to create an "alibi" by disclosing over-the-counter medicines and foods known to cross-react with the drugs they've been taking. Some people have procured a legal prescription from a family physician, such as one for codeine cough syrup, to disclose in case the test comes up positive for use of an illicit drug, such as heroin.