Trazodone is mostly cleared from your body within two to three days after your last dose. The drug has an average elimination half-life of about 10 to 13 hours, meaning half of it is gone from your bloodstream in that time. After five to six half-lives, the drug is considered fully eliminated, which puts the typical window at roughly 50 to 78 hours, or two to three days for most people.
How Trazodone Is Processed in Your Body
After you swallow a dose, trazodone is absorbed through the gut and reaches peak blood levels within about 1.5 to 2.5 hours, depending on whether you’ve eaten recently. Food slows absorption slightly. Your body absorbs 70% to 90% of an oral dose into the bloodstream, which is relatively high for a medication.
Your liver does the heavy lifting when it comes to breaking trazodone down. The main enzyme involved is one called CYP3A4, which converts trazodone into several byproducts. One of those byproducts, called mCPP, is still active in the body, meaning it can produce effects of its own. However, mCPP has a shorter half-life of just 2 to 6 hours, so it clears out faster than the parent drug.
Factors That Slow or Speed Up Clearance
Not everyone clears trazodone at the same rate. Several factors can shift that two-to-three-day window significantly.
Age and sex. In a study comparing younger adults (18 to 40) with older adults (60 to 76), elderly men cleared trazodone substantially slower. Their elimination half-life averaged 8.2 hours compared to 4.7 hours in younger men, largely because their liver processed the drug less efficiently. Older women also showed a longer half-life (7.6 vs. 5.9 hours), though the difference was smaller. For an older man, full clearance could take closer to four days rather than two.
Other medications. This is one of the biggest variables. Drugs that block the CYP3A4 enzyme dramatically slow trazodone’s exit from your system. In one study, a strong CYP3A4 inhibitor more than doubled trazodone’s half-life and increased total drug exposure by 2.4 times. Certain antifungal medications, HIV medications, and grapefruit juice in large amounts can all have this effect. On the other end, drugs that rev up CYP3A4 (like the seizure medication carbamazepine) can slash trazodone blood levels by as much as 76%, pushing it out of your system much faster.
Liver function. Because trazodone depends almost entirely on the liver for breakdown, any condition that impairs liver function, such as cirrhosis or hepatitis, will extend how long the drug lingers.
Dose and duration of use. A single low dose clears faster than a higher dose taken daily. When you take trazodone regularly, it builds up to what’s called a steady-state concentration. At a 50 mg dose, steady state is reached within about 36 hours. Once you stop, clearance begins from that higher baseline, so it takes longer to fully leave your system than it would after a single pill.
Detection on Drug Tests
Trazodone is not a controlled substance and isn’t part of standard drug screening panels. However, it has occasionally caused false-positive results on certain immunoassay urine tests for amphetamines or MDMA (ecstasy). If this happens, a confirmatory test using more precise methods will rule out the false positive. Trazodone itself is unlikely to cause problems on a workplace or pre-employment drug screen, but if you’re concerned, having your prescription information available can resolve any ambiguity quickly.
In blood, trazodone is generally detectable for one to two days after the last dose. In urine, the drug and its metabolites may show up for roughly two to four days, though this varies based on the factors described above. Hair testing, which is rarely used for trazodone specifically, can theoretically detect drug residues for up to 90 days, but this is not standard practice.
What This Means if You’re Stopping Trazodone
Even though trazodone clears from your blood within a few days, your brain may take longer to readjust. Stopping abruptly after regular use can cause discontinuation symptoms like irritability, anxiety, dizziness, and sleep disruption. These aren’t caused by the drug still being in your system but rather by your brain adapting to its absence. Tapering the dose gradually over days or weeks, rather than stopping all at once, reduces the likelihood of these rebound effects.
If you’ve been taking trazodone at a low dose for sleep (50 to 100 mg), the adjustment period is generally shorter and milder than for someone taking higher doses for depression. Either way, the drug itself will be physically gone from your body well before any discontinuation symptoms fully resolve.