Celexa Side Effects: What to Expect and When to Call Your Doctor

Updated:

March 29, 2026

Author:

Peter Daggett

Summarize this blog with AI:

Learn about Celexa (Citalopram) side effects, from common ones like nausea and drowsiness to serious warnings. Know when to call your doctor.

What You Need to Know About Celexa Side Effects

Starting a new antidepressant comes with questions — and some anxiety about side effects. If your doctor has prescribed Celexa (Citalopram), knowing what to expect can help you feel more prepared and more confident about your treatment.

This guide covers the most common side effects, the serious ones to watch for, and exactly when you should call your doctor.

What Is Celexa?

Celexa is the brand name for Citalopram, a selective serotonin reuptake inhibitor (SSRI). It's FDA-approved for treating major depressive disorder in adults and is also prescribed off-label for anxiety, OCD, and panic disorder. It works by increasing serotonin levels in the brain, which helps regulate mood.

Common Side Effects

Most people experience some side effects when they first start Celexa. These are usually mild and tend to improve within the first 1–2 weeks as your body adjusts. Based on FDA labeling, the most common include:

  • Nausea — The most frequently reported side effect. Taking Celexa with food can help.
  • Dry mouth — Stay hydrated and consider sugar-free gum or lozenges.
  • Drowsiness — Some people feel sleepy, especially at first. If this happens, try taking Celexa at bedtime.
  • Insomnia — Paradoxically, some people have trouble sleeping. If so, switch to a morning dose.
  • Increased sweating — More noticeable during exercise or in warm weather.
  • Sexual dysfunction — Includes decreased libido, delayed ejaculation, erectile dysfunction, and difficulty reaching orgasm. This is one of the most common reasons people consider switching medications.
  • Diarrhea or constipation — GI effects are common with SSRIs and usually temporary.
  • Fatigue — May overlap with drowsiness; tends to improve over time.
  • Dizziness — Especially when standing up quickly. Rise slowly from sitting or lying positions.
  • Tremor — Mild shaking, usually in the hands.
  • Loss of appetite — Some people eat less when starting Celexa.
  • Yawning — Excessive yawning is a surprisingly common SSRI side effect.

Important: Most of these side effects are temporary. If they persist beyond 2–3 weeks or significantly interfere with your daily life, talk to your doctor about adjusting your dose or trying an alternative medication.

Serious Side Effects

While uncommon, Celexa can cause serious side effects that require immediate medical attention:

QT Prolongation

Celexa can affect your heart rhythm, specifically prolonging the QT interval. This is dose-dependent — the risk is higher at doses above 40 mg/day, which is why the FDA lowered the maximum recommended dose. Symptoms include irregular heartbeat, fainting, or feeling like your heart is racing. This is also why patients over 60 are limited to 20 mg/day.

Serotonin Syndrome

This is a potentially life-threatening condition caused by too much serotonin. It's most likely when Celexa is combined with other serotonergic drugs (see our drug interactions guide). Symptoms include agitation, confusion, rapid heart rate, high blood pressure, muscle twitching, and high fever. Seek emergency care immediately if you experience these.

Suicidal Thoughts (Black Box Warning)

The FDA requires a black box warning on all antidepressants: they may increase suicidal thinking and behavior in children, adolescents, and young adults (ages 18–24), especially during the first few months of treatment or when doses change. If you notice worsening depression, new or unusual thoughts of self-harm, or sudden mood changes, contact your doctor or call 988 (Suicide & Crisis Lifeline) immediately.

Hyponatremia (Low Sodium)

Mostly seen in elderly patients or those taking diuretics. Symptoms include headache, confusion, weakness, and in severe cases, seizures.

Abnormal Bleeding

SSRIs can affect platelet function. This risk increases if you also take blood thinners, aspirin, or NSAIDs like Ibuprofen. Watch for unusual bruising, nosebleeds, or blood in your stool.

Other Serious Effects

  • Seizures — Rare but possible, especially at higher doses.
  • Manic episodes — If you have bipolar disorder, Celexa could trigger a manic episode.
  • Angle-closure glaucoma — Seek care if you experience eye pain, vision changes, or swelling around the eyes.

Specific Populations

Adults Over 60

The maximum dose is 20 mg/day due to increased risk of QT prolongation and hyponatremia. Side effects like dizziness and drowsiness also carry a higher fall risk in older adults.

Pregnant or Breastfeeding

Celexa is FDA Pregnancy Category C. It should only be used during pregnancy if the potential benefit justifies the risk. Babies exposed to SSRIs in the third trimester may experience withdrawal symptoms after birth. Celexa is also excreted in breast milk — discuss risks with your OB/GYN.

Young Adults (Under 25)

The black box warning applies most directly here. Close monitoring during the first few months of treatment is essential.

CYP2C19 Poor Metabolizers

Some people metabolize Celexa slowly due to genetics. If you're a CYP2C19 poor metabolizer, your doctor should limit your dose to 20 mg/day to avoid higher-than-normal drug levels.

How to Manage Side Effects

Here are practical strategies that can help:

  • Nausea: Take Celexa with food. This is the simplest fix and works for most people.
  • Insomnia: Take your dose in the morning instead of at night.
  • Drowsiness: Take your dose at bedtime. Give it 1–2 weeks before deciding it's a problem.
  • Sexual side effects: Talk to your doctor. Options include lowering the dose, adding Bupropion, or switching to an antidepressant with fewer sexual side effects like Bupropion (Wellbutrin).
  • Dizziness: Stand up slowly. Stay hydrated.
  • Dry mouth: Sip water throughout the day, use sugar-free gum.

Do not stop Celexa abruptly. Stopping suddenly can cause discontinuation syndrome — symptoms like dizziness, nausea, irritability, brain zaps, and flu-like feelings. Always taper off gradually under your doctor's guidance.

Final Thoughts

Side effects are a normal part of starting any antidepressant, and most of Celexa's common side effects are mild and temporary. The key is knowing what to expect, giving your body time to adjust, and communicating openly with your doctor.

If side effects are intolerable, don't suffer in silence — there are other options, including dose adjustments and alternative medications that may work better for you.

Looking for Celexa at the best price? Check out our guide to coupons and discounts, or search Medfinder to find it in stock near you.

How long do Celexa side effects last?

Most common side effects like nausea, drowsiness, and dizziness improve within 1 to 2 weeks as your body adjusts. Sexual side effects may persist longer. If any side effect lasts more than 2 to 3 weeks, talk to your doctor about adjusting your dose.

Does Celexa cause weight gain?

Celexa may cause modest weight changes in some people, but significant weight gain is less common compared to some other antidepressants like Paroxetine (Paxil) or Mirtazapine. Some people actually lose weight initially due to decreased appetite.

Can Celexa cause heart problems?

Celexa can prolong the QT interval, which affects heart rhythm. This risk is dose-dependent and is why the FDA set the maximum dose at 40 mg per day (20 mg for patients over 60). Tell your doctor about any heart conditions before starting Celexa.

What happens if you stop Celexa suddenly?

Stopping Celexa abruptly can cause discontinuation syndrome with symptoms like dizziness, nausea, irritability, brain zaps, and flu-like feelings. Always taper off gradually under your doctor's supervision to minimize these effects.

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