I took.5 mg of xanax (alprazolam) for the first time in probably 6 to 9 months. One time only every few months but i wanted to know how long it would be in my system consider i have to take a drug test in about 2 weeks. When a person is trying to manage withdrawal from an addictive substance, it can be important to understand how the drug works in the body and how long it takes for the drug to be completely eliminated from the system. i am currently prescribed two medications, one of which is xanax, which the doc told me to quit taking even though i am prescribed it.how long does it usually take for xanex to rid ur system to in order to pass a urine drug screen?i take very low doses of xanex from 1mg a day for the past 3 days How long Xanax stays in your system differs based upon each. However, what is most common is that Xanax takes about 9 – 16 hours to be reduced by 50% in the blood. This process is known as “Xanax half-life elimination.” For Xanax to come out of the system entirely, it takes about four days. However, this is only if you or your loved one has not used any more of the drug after last use. Factors that influence how long Xanax (Alprazolam) stays in your system It is important to realize that there is significant variation in clearance time of Xanax based on a multitude of factors – most of which are based on the individual. How Long Does Xanax Stay in Your Saliva? According to a 2015 report published in the journal Therapeutic Drug Monitoring , an alprazolam concentration of one nanogram per milliliter can be found in saliva for up to 2 1/2 days. Xanax is likely the most popular drug in the benzodiazepine class. Benzodiazepines are used to treat anxiety, muscle spasms, seizures, and sleep disorders by depressing the central nervous system. Anyway, I have rambled on a bit more, but to answer your question, yes, Xanax does not stay in your body that long at all (48 hours, unless u have been taking more over a shorter period of time then it can build up a little bit and stay in the body longer). You may be wondering how long does Xanax stay in your system, blood, hair and last in your urine if you are new to consume it. keep reading to know about different doses (mg) for different patients. It works by acting on gamma-aminobutyric acid ( GABA ) – a neurotransmitter in the brain.