When used for sleep, trazodone is typically prescribed at doses between 25 and 100 mg, with most prescribers considering 100 mg the practical upper limit for insomnia. The FDA-approved maximum dose of trazodone is 400 mg per day (or 600 mg per day for hospitalized patients), but those higher doses are for treating depression, not sleep problems. Going above 100 mg for sleep alone rarely adds benefit and increases the likelihood of side effects.
Why Sleep Doses Stay Low
Trazodone’s sedative effects come from a different mechanism than its antidepressant effects, and this distinction is what keeps sleep doses in a narrow range. At low doses (25 to 100 mg), the drug primarily blocks histamine and certain serotonin receptors in the brain. Receptor modeling estimates that a 50 mg dose already occupies about 84% of the brain’s histamine receptors responsible for drowsiness. By 100 mg, there’s little additional sedation to gain from pushing the dose higher.
At doses above 150 mg, trazodone starts behaving more like an antidepressant by blocking serotonin reuptake, similar to SSRIs. This shift doesn’t make you sleepier. It changes the drug’s overall profile in ways that increase the chance of side effects without improving sleep quality. That’s why most clinicians cap the sleep dose well below the antidepressant range.
Typical Dosing for Insomnia
Most prescribers start at 25 to 50 mg taken about 30 minutes before bed. If that’s not effective, the dose may be increased in 25 mg increments over a period of days or weeks. The ceiling for sleep is generally 100 mg, though some providers will go as high as 150 mg in specific situations. It’s worth noting that trazodone is not FDA-approved for insomnia. Its only approved indication is major depressive disorder in adults, so all prescribing for sleep is considered off-label.
The American Academy of Sleep Medicine’s clinical practice guideline actually recommends against using trazodone for insomnia, issuing a “weak” recommendation that clinicians not use it for sleep onset or sleep maintenance problems. Despite this, trazodone remains one of the most commonly prescribed medications for sleep in the United States, largely because it’s inexpensive, non-addictive, and doesn’t carry the controlled substance restrictions that apply to many dedicated sleep medications.
Why Higher Doses Cause More Problems
As the dose increases beyond the sleep range, side effects become more noticeable. The most common issue is next-day grogginess. Trazodone has a half-life of roughly 5 to 13 hours, meaning it can linger in your system well into the morning, especially at higher doses. At 50 mg, most people clear enough of the drug overnight to feel alert. At 100 mg or above, some people feel foggy or sluggish the next day.
Trazodone also blocks receptors that help regulate blood pressure, which can cause dizziness or lightheadedness when you stand up quickly. This effect is dose-dependent and becomes more pronounced above 100 mg. For older adults, this increases the risk of falls, particularly during nighttime bathroom trips.
In men, trazodone carries a rare but serious risk of prolonged erections. One study of 229 male patients taking trazodone found that about 8% developed prolonged erections after starting the medication, though none in that study progressed to priapism (a painful, sustained erection requiring emergency treatment). This risk exists even at low doses but is something to be aware of at any dose level.
Serotonin Syndrome Risk
One of the more serious concerns with trazodone at any dose is serotonin syndrome, a potentially life-threatening reaction that occurs when too much serotonin builds up in the body. This risk rises significantly if you take trazodone alongside other medications or supplements that affect serotonin levels: tricyclic antidepressants, the cough suppressant dextromethorphan, buspirone, tryptophan, or 5-HTP supplements.
An unexpected source of risk is melatonin supplements. One study found that 8 out of 31 melatonin products tested contained unlabeled 5-HTP, a serotonin precursor. Combining contaminated melatonin with trazodone could increase serotonin syndrome risk, which is particularly relevant since people using trazodone for sleep might also be trying melatonin. Serotonin syndrome can occur at prescribed doses, not just in overdose situations, so the combination of trazodone with any serotonin-affecting substance deserves attention.
What This Means in Practice
If you’re taking trazodone for sleep and it’s not working at your current dose, the answer isn’t necessarily to keep increasing. Most of the drug’s sleep benefit is concentrated between 25 and 100 mg. Beyond that, you’re more likely to accumulate side effects than gain better sleep. If 100 mg isn’t doing enough, that’s typically a signal to explore other approaches rather than push toward the antidepressant dose range, which tops out at 400 to 600 mg but serves an entirely different purpose.