Xanax XR usually doesn't last any longer than about 10-12 hours max for most people even though it's supposed to be 18 hours. I've never heard of it working 18 hours for anyone. **DROP A LIKE & SUB IF YOU ENJOYED THE VIDEO!** In todays video, I talk about doing xanax at work. I do not recommend trying xanax at work or at home, as xanax is a seriously terrible drug. How long does Xanax take to work? Alprazolam (Xanax) is a drug that relieves anxiety within about half an hour of oral intake. Most people who use Xanax say that a single dose kicks in 15- 30 minutes and its anti-anxiety effects last for a few hours. Laurie is right, but there is also xanax extended release, that might be an option, I took it for sometime and it is a lot better than the immediate release one, for me. Depends on 2 things how much was the dose (.25.5, 1mg, 2mg) and your tolerance and how much food you have in your stomach. If its a higher dose then you normally take I'd say 15-30 max and thats not on a full stomach I find that if I havent eaten recently the xanax hits me faster. How Long Does Xanax Work? When you take Xanax, the effects tend to take hold quickly, but they don’t last long. Xanax has a relatively short half-life, meaning it doesn’t take long for its effects to reach a peak after it is ingested. How long does it take for the effects of Xanax to wear off? One way to find out how long a drug will last in the body is to measure its half-life. Xanax (generic name alprazolam) definitely does work. Most people find, that with the right dose, they can effectively control anxiety to the point where it doesn’t bother them. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Pappas on how long does xanax take to work: Some effects are noted within 10-15min and is due to the acetaminophen. The opioid effect can take up to 45 min to be noted as it needs to get converted to the active drug in the liver. This make it a bad choice for. Whether or not you have anxiety, you’ve probably heard of Xanax. Reactions uncovers the chemistry behind this popular and widely prescribed drug, and answers the question of how does Xanax work?.