Trazodone is typically prescribed at 25 to 50 mg taken at bedtime for sleep, with a maximum dose of 200 mg. This is well below the doses used for depression (150 to 400 mg), because the sleep-promoting effects kick in at much lower amounts than the antidepressant effects.
Why Low Doses Work for Sleep
Trazodone’s sedative effect is dose-dependent in an unusual way. At low doses, it blocks three types of receptors in the brain: serotonin receptors (specifically 5-HT2A), histamine receptors, and adrenaline receptors. All three of these contribute to wakefulness, so blocking them makes you drowsy. At higher doses, trazodone starts activating different serotonin pathways that treat depression but don’t necessarily add more sleepiness. That’s why 25 to 50 mg can knock you out even though it would be considered a subtherapeutic dose for mood.
Most prescribers start at the low end, around 25 mg, and increase in small increments if needed. Some people respond well to 50 mg, while others may need 100 mg or occasionally up to 200 mg. The goal is to find the lowest effective dose because side effects like next-day grogginess and dizziness tend to increase with higher amounts.
How Well It Actually Works
Trazodone’s reputation as a sleep aid is better than its clinical trial data might suggest. A meta-analysis of randomized, placebo-controlled trials found that trazodone significantly reduced the number of nighttime awakenings compared to placebo and improved how people rated their own sleep quality. However, it did not produce statistically significant improvements in how quickly people fell asleep, total sleep time, or time spent awake after initially falling asleep.
In practical terms, trazodone seems to help most with sleep maintenance rather than sleep onset. If your main problem is waking up repeatedly during the night, it may be a good fit. If your issue is lying awake for an hour trying to fall asleep in the first place, the evidence is less convincing. That said, many people report subjectively sleeping better on trazodone even when objective measurements don’t show dramatic changes, which suggests it may improve sleep quality in ways that standard metrics don’t fully capture.
Common Side Effects at Sleep Doses
Because trazodone blocks adrenaline receptors, it can lower blood pressure. The most noticeable version of this is feeling dizzy or lightheaded when you stand up quickly, especially in the first few days. Taking it right before getting into bed (rather than on the couch an hour before) helps reduce the risk of a fall.
Next-day drowsiness is the other common complaint, particularly at doses above 50 mg. Trazodone has a half-life of about 5 to 9 hours, so higher doses can leave a hangover effect into the morning. Dry mouth, headache, and nausea occur in some people but tend to be mild.
One rare but serious side effect in men is priapism, a prolonged, painful erection unrelated to sexual arousal. The estimated incidence is between 1 in 1,000 and 1 in 10,000 male patients, with most cases occurring within the first month. This is a medical emergency that requires immediate treatment to prevent permanent damage.
Medications That Change How Trazodone Works
Trazodone is broken down in the liver by a specific enzyme called CYP3A4. Drugs that slow down this enzyme can cause trazodone to build up in your system, sometimes dramatically. In one study, a common antiviral drug increased trazodone blood levels by 2.4 times and doubled how long it stayed active, causing drops in blood pressure and fainting. Certain antifungal medications and some HIV drugs have similar effects. If you take any of these, a lower dose of trazodone is typically necessary.
The opposite problem happens with drugs that speed up CYP3A4. Carbamazepine, an anti-seizure medication, reduced trazodone blood levels by 76% in one study, potentially making it ineffective. If you’re on a medication that revs up this enzyme, you may need a higher trazodone dose to get the same sleep benefit.
How to Take It for Best Results
Take trazodone 30 minutes before you want to be asleep. Unlike some sleep medications that take over an hour to work, trazodone tends to produce drowsiness relatively quickly, and taking it too early can leave you groggy on the couch rather than in bed. Always take it with a small snack or shortly after eating, since food increases absorption and reduces the chance of nausea.
Trazodone is not considered habit-forming in the way that benzodiazepines or Z-drugs are, which is one reason it became so widely prescribed for insomnia. It doesn’t produce the same tolerance pattern where you need progressively higher doses. That said, stopping abruptly after regular use can cause rebound insomnia and irritability, so tapering down gradually is the standard approach if you decide to stop.