A single 50mg dose of trazodone is mostly cleared from your body within 1 to 2 days, with the drug becoming undetectable in blood after roughly 2 to 3 days. The exact timeline depends on your metabolism, liver health, and whether you’ve been taking it regularly or just once.
How Trazodone Leaves Your Body
Trazodone’s elimination half-life, the time it takes for your body to clear half the drug from your bloodstream, ranges from about 5 to 12 hours depending on the individual. Quest Diagnostics lists the typical range as 7 to 10 hours. After each half-life, half of what remains gets cleared, so the drug steadily tapers down rather than disappearing all at once.
A drug is considered effectively eliminated after 4 to 5 half-lives, when 94% to 97% of it is gone. Using the average half-life of roughly 7 to 10 hours, a single 50mg dose would be virtually cleared in about 35 to 50 hours, or roughly 1.5 to 2 days. If your metabolism runs on the slower end (closer to a 12-hour half-life), full clearance could stretch to about 2.5 days.
Your liver does almost all the work. Trazodone is extensively broken down there, and less than 1% leaves your body unchanged through urine. About 70% to 75% of a dose is excreted through urine within 72 hours, mostly as metabolites rather than the original drug. The rest exits through feces.
Peak Effects and the Two-Phase Decline
After you swallow a 50mg tablet, trazodone reaches its peak concentration in your blood in about one hour when taken with food. This is when sedation and other effects are strongest, which is why most people who take it for sleep notice drowsiness within 30 to 60 minutes.
Plasma levels then drop in two distinct phases. The first phase is relatively fast, with a half-life of about 3 to 6 hours, which is when you’ll feel the most noticeable decline in effects. The second, slower phase has a half-life of about 5 to 9 hours as your body clears the remaining traces. This biphasic pattern explains why some people feel groggy the morning after taking trazodone, even though the strongest effects wore off hours earlier.
The Active Metabolite Lingers Slightly
When your liver breaks down trazodone, one of the byproducts is an active metabolite called mCPP. This compound has its own biological effects and its own timeline. Its elimination half-life ranges from about 2.6 to 6.1 hours, with effects peaking 1 to 2 hours after the parent drug is metabolized and lasting 4 to 8 hours. For a single 50mg dose, this metabolite adds a few extra hours to the total window during which drug-related compounds are circulating, but it clears relatively quickly on its own.
Single Dose vs. Regular Use
If you’ve only taken one 50mg tablet, the timeline above applies fairly directly. But if you’ve been taking trazodone daily, the drug accumulates to what’s called a steady-state concentration, which takes about 4 days of consistent dosing to reach. At steady state, your body always has a baseline level of the drug circulating, so clearance after your last dose takes longer than it would from a single pill. You’d need to add roughly a day or two to the clearance window, meaning it could take 3 to 4 days after stopping regular use for the drug to fully leave your system.
What Slows Clearance Down
Because trazodone relies heavily on liver metabolism, anything that affects liver function can extend how long it stays in your system. People with liver impairment will clear the drug more slowly, though formal studies in this population haven’t been completed. The same caution applies to kidney impairment, since the kidneys handle excretion of the metabolites.
Age is another factor. Older adults often have reduced liver and kidney function even without a diagnosed condition, which can slow processing. Eating a high-fat meal around the time you take trazodone lowers the peak concentration by about 31% but slightly increases overall drug exposure, meaning absorption is spread out over a longer window. Other medications matter too: drugs that inhibit the liver enzyme CYP3A4 (common examples include certain antifungals and antibiotics) can slow trazodone’s breakdown and extend its presence in your body.
Drug Testing and False Positives
Standard urine drug screens do not specifically test for trazodone, and at a normal 50mg dose, it’s unlikely to cause issues. However, there are documented cases of trazodone triggering a false positive for amphetamines on immunoassay-based screening tests, particularly at higher doses. These initial screening tests are less precise than confirmatory testing. If a false positive occurs, a follow-up test using more specific methods will distinguish trazodone metabolites from actual amphetamines and clear the result.
For anyone concerned about timing around a drug test, a single 50mg dose and its metabolites are largely gone from urine within 72 hours. Regular users should allow 4 to 5 days to be safe.