Medically Approved

What to expect during your first week on Zoloft


Optum Perks Author

By Optum Perks Author

Zoloft, a brand of the antidepressant sertraline, is a selective serotonin reuptake inhibitor (SSRI). This means that it works by increasing the serotonin levels in your brain. Zoloft may be used to treat:

  • Major depressive disorder (MDD)
  • Posttraumatic stress disorder (PTSD)
  • Premenstrual dysphoric disorder (PMDD)
  • Panic disorder
  • Scial anxiety disorder
  • Obsessive-compulsive behavior in kids ages 6-17

Your doctor may start you on a low dose and gradually increase the dose over time. It’s common to experience headaches, nausea, and fatigue during your first week on Zoloft. These side effects often get better over the first week or two.

What are the side effects? 

It may take a couple of weeks or more to feel the full benefits of Zoloft. Like most antidepressants, Zoloft may cause side effects. Common side effects may last a week or two until your body gets used to taking the medication.


Common side effects include:

  • Nausea
  • Headache
  • Fatigue
  • Constipation
  • Insomnia
  • Heartburn
  • Dizziness
  • A change in weight
  • Tremor
  • Sweating
  • Decrease in appetite

Contact your doctor if these symptoms don’t go away after a few weeks. They may suggest changing your dose or medication until you find what works best for you. Don’t stop taking Zoloft on your own without talking to your doctor first. A sudden change in medication may cause withdrawal symptoms.


More serious, but less common side effects include:

  • Seizures
  • Bruising or abnormal bleeding
  • Hallucinations
  • Loss of coordination
  • Memory loss
  • Rash
  • Hives
  • Shortness of breath

Contact your doctor or 911 if you experience any of these serious side effects, regardless of when they occur.

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Safety and risks

Although Zoloft is safe for most people, it’s not for everyone. Don’t take Zoloft without first talking to your doctor if:

  • You’re pregnant. Zoloft may cause problems in newborns.
  • You’re taking monoamine oxidase inhibitors (MAOIs). Your doctor may prescribe you something else or take you off MAOIs before starting you on Zoloft.
  • You take other prescription and nonprescription medications, supplements, or vitamins. Antidepressant medications can interact with other medications. Your doctor may adjust your dose if you’re currently taking other medications.
  • You recently had a stroke or heart attack. Your doctor may prescribe you something else, or may start you on Zoloft and monitor your side effects.

Zoloft may cause drowsiness. Don’t drive a vehicle or operate heavy machinery while taking Zoloft.

Missed dose

If you forget to take a dose of Zoloft, take it when you remember, unless the time is closer to your next dose. Don’t take a double dose.


Call 911 or the Poison Control Helpline at 1-800-222-1222 if you overdose on Zoloft. Signs that you have overdosed may include:

  • Drowsiness
  • Hallucinations
  • Severe muscle stiffness
  • Twitching
  • Excessive fatigue
  • Mania
  • Seizures
  • Loss of consciousness

Suicidal thoughts

Depression and other mental illnesses may cause suicidal thoughts and actions. Zoloft and other antidepressants may increase suicidal ideation in children, teens, and young adults within the first couple of months of treatment. Pay attention to your body when you take Zoloft and call your doctor, 911, or the National Suicide Prevention Lifeline if you have thoughts of self-harm.

The takeaway  

Common side effects during the first week or two of taking Zoloft include nausea, headache, fatigue, and constipation. These side effects should go away once your body gets used to the medication.


If you continue to have side effects after a few weeks or experience any serious side effects, call your doctor or 911.