How long does fentanyl stay in your system?

Howls long does fentanyl stay in your system? Specifically when smoked. I've heard a lot of conflicting information on this.

 

I'm quite certain than smoking an opiod other than opium itself (which is actually vaporized at a low temperature) is a HUGE waste. To answer your question, I'd say about 3 days, like other opiates. It's fully synthetic though so it may be shorter or longer.

 

Heroin base and fentanyl can be smokes efficiently as well.

 

I'm pretty sure it's shorter because fentanyl has a much shorter half life han mos opiates/opioids. I'm just not sure to what extent.

 

Take the half life, multiply it by 5 to 7, and this is how long it is in your system. To see how long it is detectable in urine, look up the drug's metabolites, and multiply each of their half lives by 5 to 7 and, voila, there is how long it will be in your urine. This doesn't work for Cannabis because THC is a diterpanoid compound and not a nitrogenous alkaloid like most opioids (and other drugs).

 

The Half life of fentanyl is what Im having trouble figuring out. I've heard everything from 2.5 minutes to 7 hours.

 

It depends on the route of administration, I believe. I found this on an opiod comparison chart: 0.04 (IV); 7 (transdermal). Going by that the range would be 2.4 min.-7 hrs, which is apparently what you found as well, lol. But I haven't found anything for smoking. Anyway, if you use etkearn's formula, at the very most it would be in your system for 2 days, but I'm guessing much shorter if it's smoked.