How Drug Tests Work
When you take a drug of any kind, it takes a certain amount of time to be fully processed and expelled from the body in waste matter. During this time, the drugs are broken down into small collections of molecules called metabolites. These metabolites are stored mostly in fatty cells, and they gradually leak out into the bloodstream and eventually into urine. This is how the body naturally cleanses itself of drugs and other substances. Metabolites created by certain classes of prohibited drugs have been well identified, and some labs use this information to conduct and process drug tests. When a person takes a drug test, he must submit a sample of some sort, usually urine, blood or hair. This sample contains traces of the groups of metabolites present in the system. When the sample is analyzed, the present metabolites are compared to those known to belong to the various classes of controlled substances. Through this method, labs can help employers, government agencies and other relevant parties determine if specific people have been taking certain classes of drugs.
Phentermine's Similarities to Controlled Substances
Phentermine, though legal with a prescription, is classified as an amphetamine. It is typically prescribed to obese people whose obesity poses other serious health risks, and it works by stimulating the brain so that feelings of hunger are less frequent and severe. The metabolites expelled by the breakdown of phentermine are structurally similar to those of other amphetamines, including illegal ones. If a person who is taking phentermine takes a drug test, he will likely test positive for amphetamines. This is possible even weeks after taking a single dose of phentermine.
How to Prepare for a Drug Test if You Take Phentermine
If you are taking phentermine legally with a prescription and are required to submit to a drug test, the safest solution may be to be upfront with all interested parties prior to taking the test. If you reveal your phentermine prescription to the person or entity requiring the test as well as the clinic staff administering it, you can make sure that the test results won't adversely affect you before you even take it. You should expect to have to produce your prescription as proof, however. If you have some reason to keep the person or entity requiring the test from knowing that you take phentermine, you should still tell the drug test clinic before you ever provide a sample. Have a frank discussion with the clinic manager or staff about the expectation that you will test positive for amphetamines and why you don't want the other interested parties to know. Oftentimes, these potential problems can be resolved confidentially between the person submitting the sample and the company conducting the test, but advance warning is often required for this to be possible. Be prepared with a printed copy of your prescription when you approach the clinic for this conversation.