Does trazodone have serotonin in it? (+3 side effects)

In this article, we will discuss the link between trazodone and serotonin. We will look further in detail at whether trazodone impacts serotonin or not. We will also discover some other medications that have a direct link with serotonin levels in the brain. 

Does trazodone have serotonin in it?

No, trazodone does not have serotonin in it. However, it has a direct effect on serotonin levels in the brain. After taking trazodone, it has the potential to alter serotonin levels but does not contain serotonin in its composition. 

Trazodone is an antidepressant medication that belongs to the serotonin antagonist and reuptake inhibitor drug class. Trazodone is an FDA-approved medication for the treatment of major depressive disorder (1).

Trazodone, however, does impact and alter the levels of serotonin but it does not contain serotonin in its composition. Due to its direct mechanism of action and effects on serotonin levels in the brain, trazodone can be mistaken to contain some amount of serotonin in it. 

How does trazodone affect serotonin levels?

Trazodone affects serotonin levels by modulating its activity. The full mechanism of the impact of trazodone is not fully understood. However, the basic mechanism indicates that trazodone inhibits serotonin transporters and serotonin type-2 receptors (1).

Trazodone inhibits the reuptake of serotonin in the synaptic cleft. This blockade of serotonin increases the concentration of serotonin in the brain thus, causing an increased serotonin activity and signaling (1). 

Trazodone is also known to block serotonin type-2 receptors. This blockade of serotonin receptors and blocking of its reuptake contributes to the antidepressant and anxiolytic activity of trazodone (1).

This combination of effects of trazodone on serotonin levels in the brain is responsible for mood-enhancing properties. Trazodone alters serotonin levels in the brain leading to enhanced mood and behavior (1). 

This unique action of trazodone makes it stand out among other antidepressants such as SSRIs and SNRIs. Due to this combined action, trazodone has a better tolerance for anxiety, irritation, sexual disturbances, and insomnia (1).

What are the trazodone-induced serotonin effects in the body?

The following are some effects of serotonin in the body induced by trazodone (1,2):

  • Mood regulation- Serotonin is a feel-good hormone. When its levels are increased due to trazodone, it uplifts and regulates mood and emotions. 


  • Sleep regulation- Serotonin is a melatonin precursor, which is involved in the sleep-wake cycle. Therefore, increased serotonin levels due to trazodone directly influence the sleep-wake cycle. 


  • Cognitive function- Serotonin is associated with cognitive functions such as learning, memory, and decision-making. 

Which side effects occur when trazodone affects serotonin levels?

Some common side effects of trazodone that occur when serotonin levels are altered in the brain include (1): 

  • Nausea
  • Vomiting 
  • Drowsiness
  • Dizziness
  • Lightheadedness
  • Fatigue
  • Dry mouth
  • Blurred vision

Some severe serotonin-associated side effects due to trazodone include serotonin syndrome and suicidal thoughts. If a patient is suffering from such severe adverse effects, then immediate medical help is required. 

However, not every patient taking trazodone may experience these side effects. Most people can easily tolerate trazodone without facing serious side effects. 

What other medications directly influence serotonin levels?

Many drug classes directly influence and alter serotonin levels in the brain (3):

  • Selective serotonin reuptake inhibitors (SSRIs)

Citalopram, Fluoxetine, Escitalopram, Paroxetine, Sertraline

  • Serotonin-norepinephrine reuptake inhibitors (SNRIs)

Venlafaxine, Desvenlafaxine, Duloxetine

  • Monoamine oxidase inhibitors (MAOIs)

Selegiline, Phenelzine, Isocarboxazid, Tranylcypromine

  • Tricyclic antidepressants (TCAs)

Amitriptyline, Nortriptyline, Imipramine, Doxepin

  • Serotonin receptor agonists

Zolmitriptan, Rizatriptan, Sumatriptan

When to consult your doctor?

You must consult your doctor if you suspect that trazodone is not showing its therapeutic efficacy or if you are facing excessive side effects due to trazodone.

Trazodone is generally a safe and effective antidepressant. It is not associated with severe side effects and does not typically mess you up, but individual patients react varyingly to medications. Some may suffer severe side effects due to trazodone while others may not. 

You must seek immediate medical help if trazodone causes excessive serotonin reuptake leading to a life-threatening condition called serotonin syndrome which is characterized by agitation, anxiety, tachycardia, nausea, vomiting, tremors, and flushed skin (4). 

You must keep monitoring yourself for such symptoms while taking trazodone. You must also do regular follow-up sessions with your doctor and get yourself assessed for any abnormal serotonin activity due to trazodone. 

As a pharmacist, I would add that it is important to know that trazodone has profound effects on serotonin levels in the brain but it does not contain serotonin in its composition. 

However, my advice is to always take medications as prescribed by your doctor because starting or stopping prescription medications such as trazodone on your own may cause severe withdrawal symptoms. 

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Shin JJ, Saadabadi A. Trazodone. [Updated 2022 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:


Bakshi A, Tadi P. Biochemistry, Serotonin. [Updated 2022 Oct 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:


Bamalan OA, Moore MJ, Al Khalili Y. Physiology, Serotonin. [Updated 2023 Jul 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:


Simon LV, Keenaghan M. Serotonin Syndrome. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:

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