Trazodone Side Effects: Grogginess, Dizziness, and Priapism

Trazodone is supposed to help you sleep, or lift your mood, so it’s unsettling when it leaves you foggy at 10 a.m. or lightheaded when you stand up. Most trazodone side effects are manageable, a few are urgent, and knowing the difference can save you a lot of worry. It also helps to know which ones are tied to your dose.

Your brain uses several receptor systems to stay awake and alert, and trazodone dials down some of them with dose-dependent precision. A pharmacology review explains that low doses block serotonin 5-HT2A, histamine H1, and alpha-1 adrenergic receptors, which makes trazodone sedating, while higher doses also block the serotonin transporter and make it an antidepressant. That’s why the same pill can feel so different at 50 mg than at 300 mg.

The standard reference for side effects is the drug label. Trazodone’s FDA prescribing information lists the common side effects from controlled trials, explains its warnings, and spells out when to seek emergency care. The data are real, and the label is where any careful conversation should start.

But those trials studied depression doses, while many people take trazodone at low, off-label doses for sleep, and at Siggy we’d rather you understand which side effects match your dose than read one long list. This guide sorts trazodone side effects by dose and urgency, from normal adjustment to an urgent call to a true emergency. The goal is decisions grounded in pharmacology and evidence.

What This Page Covers

• How Your Dose Shapes Side Effects
• The Most Common Side Effects
• Why Trazodone Can Leave You Groggy
• Dizziness When You Stand Up
• The Priapism Warning
• Rare but Serious Risks
• When to Call Your Prescriber

How Your Dose Shapes Side Effects

Trazodone is FDA approved for depression in adults, with outpatient doses usually starting at 150 mg a day and topping out at 400 mg. Using it for sleep is off-label, and sleep doses are often much lower.

That dose gap matters. At low doses, the sedating receptor effects dominate, so the side effects people notice most are sleepiness, next-day grogginess, and dizziness. At depression doses, trazodone also blocks serotonin reuptake, which is thought to drive its antidepressant effect, and the label’s trial data and warnings were built around that dose range.

The evidence at sleep doses is thinner. A Cochrane review of antidepressants for insomnia found low-quality evidence from two trials that trazodone caused more morning grogginess, dry mouth, and thirst than placebo. It also noted that adverse events were poorly reported overall, so the full picture at low doses isn’t settled.

The Most Common Side Effects

The FDA label’s outpatient trial data show which effects are most common. These trials used depression doses, so rates at sleep doses may differ:

Side Effect	Trazodone	Placebo
Drowsiness	41%	20%
Dry mouth	34%	20%
Dizziness or lightheadedness	28%	15%
Headache	20%	16%
Blurred vision	15%	4%
Nausea or vomiting	13%	10%

Some of these overlap with placebo more than you might expect. Headache and nausea rates were only a few points higher on trazodone, while drowsiness, dizziness, and blurred vision showed bigger gaps.

In sleep trials specifically, a 2025 network meta-analysis of insomnia medicines found trazodone roughly tripled the risk of somnolence compared with placebo (relative risk 2.86). That’s similar to many other sleep medicines in the same analysis.

Why Trazodone Can Leave You Groggy

Grogginess is the flip side of what makes trazodone work for sleep. The histamine and 5-HT2A blockade that helps you fall asleep doesn’t switch off at sunrise, and for some people it carries into the morning. If mornings feel foggy, our guide to trazodone’s daytime side effects goes deeper on cognitive effects and falls.

The label gives a few practical clues. It says trazodone should be taken shortly after a meal or light snack, and that drowsiness may call for moving most of the dose to bedtime or lowering it. Food also changes how trazodone is absorbed: the label says it may increase the total amount absorbed while lowering the peak level and delaying when it’s reached.

What tends to help, with your prescriber’s input:

• Ask whether your dose or timing can change, such as taking it earlier in the evening
• Don’t drive or operate machinery until you know how trazodone affects you, as the label advises
• Avoid alcohol and other sedatives, which the label says trazodone can intensify
• Keep a simple log of dose time, wake time, and how alert you feel, then share it

Dizziness When You Stand Up

Trazodone blocks alpha-1 adrenergic receptors, which help your blood vessels tighten when you stand. The label links this property to postural hypotension, a drop in blood pressure on standing, and it reports hypotension and fainting. If you also take blood pressure medicine, the label notes that dose may need to be lowered.

This matters most at night and in older adults. A large nursing home cohort study found fall-related injuries within 90 days in 5.7% of new low-dose trazodone users and 6.0% of matched new benzodiazepine users, so trazodone was no safer on falls.

MedlinePlus drug guidance suggests getting out of bed slowly and resting your feet on the floor for a few minutes before standing. Tell your prescriber if you feel faint, because that’s a reason to review the dose.

The Priapism Warning

Priapism is a prolonged, often painful erection that isn’t related to sexual arousal. It’s rare with trazodone, but it’s serious, and the label is unusually direct about it.

According to the label, an erection lasting more than 4 hours, whether painful or not, means you should stop trazodone and seek emergency care immediately. Priapism that isn’t treated promptly can cause permanent damage to erectile tissue. The label advises extra caution for men with conditions that raise priapism risk, such as sickle cell anemia, multiple myeloma, leukemia, or Peyronie’s disease.

How rare is it? A 2023 clinical review describes priapism with trazodone as rare. Still, in an FDA adverse event analysis, trazodone had about twice as many priapism reports as the erectile dysfunction pills sildenafil, tadalafil, and vardenafil combined, which is why the warning gets so much attention. The label’s postmarketing reports also include clitorism, a prolonged and painful clitoral erection, so women should report similar symptoms too.

Rare but Serious Risks

Beyond priapism, the label lists several less common warnings:

• Heart rhythm changes: Trazodone can prolong the QT interval, and rhythm problems have been reported at doses of 100 mg a day or less. Tell your prescriber about heart disease or other QT-prolonging medicines.
• Serotonin syndrome: The risk rises when trazodone is combined with other serotonergic drugs, such as SSRIs, triptans, or tramadol.
• Bleeding: Aspirin, NSAIDs, and blood thinners can add to trazodone’s bleeding risk.
• Low sodium: Headache, confusion, weakness, or unsteadiness can signal it, and older adults and people taking diuretics are at higher risk.
• Eye pressure: In people with untreated narrow angles, trazodone can trigger angle-closure glaucoma.
• Mood shifts: Like all antidepressants, trazodone carries a boxed warning about suicidal thoughts in people under 25, and it may trigger mania in people with bipolar disorder.

When to Call Your Prescriber

This table sorts symptoms by urgency, based on the FDA label and Medication Guide:

How Urgent	Symptoms	What to Do
Emergency	Erection over 4 hours, fainting, racing or irregular heartbeat, fever with agitation and stiff muscles	Call 911 or go to the emergency room
Urgent	Eye pain or vision changes, unusual bleeding, confusion or unsteadiness, new or worse mood symptoms	Get medical help right away
Next check-in	Morning grogginess, dry mouth, mild headache, mild nausea	Tell your prescriber, since timing or dose can often change

If you have thoughts of suicide, call or text 988 to reach the Suicide and Crisis Lifeline. If you’re unsure which row fits, call your prescriber, or call 911 if symptoms feel severe.

Don’t stop trazodone suddenly because of mild side effects, except in an emergency like priapism, where the label says to stop. The label advises lowering the dose gradually when possible.

Not knowing whether a symptom is a side effect is a common frustration in the gap between starting a medication and getting answers about it.

Most trazodone side effects are predictable once you know your dose: sedation and dizziness at low doses, with serotonin effects added at higher ones. The rare serious ones, like priapism and heart rhythm changes, need fast action. If you take trazodone mainly for sleep, our guide to low-dose trazodone for sleep covers how it works and who it suits.

Ready to take control of your mental health? Start your anonymous intake with Siggy and get your plan reviewed by a licensed prescriber.

This article is for education only and isn’t a substitute for personal medical advice. Don’t change or stop a medication without talking to your prescriber, except in an emergency described here. It was reviewed for clinical accuracy and reflects sources available as of September 2026.