Why am I so tired on sertraline?

Feeling tired or drowsy is a common side effect of sertraline, and it can affect some people more than others. There are several reasons why you might feel tired while taking sertraline:

  1. Serotonin levels: Sertraline works by increasing the levels of serotonin in the brain. Higher levels of serotonin can cause drowsiness and fatigue.
  2. Dosage: Taking a higher dose of sertraline can cause more drowsiness than a lower dose.
  3. Timing of medication: Taking sertraline at night may increase the likelihood of feeling tired during the day.
  4. Other medications: Taking other medications that cause drowsiness, such as antihistamines or benzodiazepines, can increase the drowsiness caused by sertraline.
  5. Underlying medical conditions: Certain medical conditions, such as sleep apnea or anemia, can cause fatigue and may be exacerbated by sertraline.

If you are experiencing excessive tiredness while taking sertraline, it is important to talk to your doctor. Your doctor may be able to adjust your dosage or recommend other strategies to help manage your fatigue. Additionally, it is important to avoid driving or operating heavy machinery if you are feeling excessively drowsy, as sertraline can impair your ability to perform these tasks safely.


There are various forms of drugs available, such as tablets or liquids, and each may have a separate patient information leaflet (PIL) for different doses. It is important to refer to the PIL for the specific form and dose of the drug that you have been prescribed.

You can search for further information and PILs on websites such as:

Can I skip a few days of sertraline?

Does sertraline cause oversleeping?