How long does trazodone stay in your system?

After a single dose in a healthy adult, trazodone will be mostly out of your system in one to three days.

For trazodone the half-life is approximately 5 to 13 hours. This means that every 5 to 13 hours, the level in your blood will drop by 50 percent.
The elimination half-life of a medication is the time it takes for blood levels of the medication to be reduced by half.

It takes on average 5.5 elimination half lives for a drug to be eliminated from your system. Metabolism, age, health, weight and the amount and frequency of the drug taken, are all factors that can affect the rate at which the body can clear the drug from your system.