Does Cymbalta contain serotonin? (3+ facts)

This article will provide an overview of Cymbalta, a medication used to treat various mental health conditions. We will also talk about the composition of this drug, the medical issues it can address, and the potential side effects that users may experience.

Does Cymbalta contain serotonin? 

No, Cymbalta does not contain serotonin, but it increases the level of serotonin in the brain. The active ingredient present in Cymbalta is duloxetine hydrochloride. Cymbalta is an antidepressant which belongs to the class of serotonin-norepinephrine reuptake inhibitors (SNRI), which is used to treat the symptoms of depression, anxiety disorders, fibromyalgia, chronic musculoskeletal pain and stress urinary inconsistency. (1,2)

Serotonin (5-HT) is a neurotransmitter which plays an important role in regulating mood, behaviour, memory, gastrointestinal homeostasis, etc. In most mental illnesses, serotonin is the primary target, and all antidepressants used in treatment increase the levels of serotonin. (3)

Serotonin is a neurotransmitter that is synthesised in the body; you can increase the level of serotonin by other means such as drugs, food, supplements, joyful activities, exercise, etc. 

What does research suggest? 

The main ingredient in Cymbalta is duloxetine, which affects the central nervous system. Research studies have shown that duloxetine (Cymbalta) acts by increasing serotonin levels along with other neurotransmitters, such as norepinephrine and dopamine. (1, 2, 4)

A study done by Chalon et al. about the effect of duloxetine on the levels of serotonin and norepinephrine in 12 healthy male subjects showed that duloxetine influences the level of whole-blood serotonin levels. The study concluded that duloxetine inhibited serotonin and norepinephrine reuptake. Hence, increasing thier levels in the body. (4)

What are the contents of Cymbalta?

Cymbalta contains duloxetine hydrochloride as its main active ingredient. Duloxetine hydrochloride functions by binding to the reuptake transporters of serotonin, resulting in an increased serotonin level. Serotonin is a neurotransmitter that regulates mood, sleep, and appetite. By increasing serotonin levels, Cymbalta can help alleviate symptoms of depression, anxiety, and chronic pain. (1,5)

The inactive ingredients in the formulation of Cymbalta are FD&C Blue No. 2, gelatin, hypromellose, hydroxypropyl methylcellulose acetate succinate, sodium lauryl sulfate, sucrose, sugar spheres, talc, iron oxide yellow, titanium dioxide and triethyl citrate. (2)

None of the tablets contain serotonin, but drugs such as antidepressants, stimulants, etc., increase the levels of serotonin in the brain, which helps you with mood, memory, pain, attention, etc. 

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

Cymbalta belongs to a class of serotonin-norepinephrine reuptake inhibitors (SNRIs), which work by inhibiting the levels of serotonin, norepinephrine and dopamine. Cymbalta-induced serotonin effects can be positive or negative.

Positive effects include Improved mood, sleep, memory, enhanced appetite, increased sexual function, pain relief, increased concentration and attention. 

Negative effects include digestive issues (nausea, vomiting), headaches, sexual dysfunction, sleep disturbances, anxiety, agitation and serotonin syndrome.  

Serotonin syndrome is caused when the level of serotonin is too high. Serotonin syndrome can also be caused by the concomitant use of Cymbalta with a monoamine oxidase inhibitor, stimulant or drugs which increase serotonin levels. The symptoms of serotonin can range from mild (headache, nausea, vomiting) to severe (seizure, fever, muscle rigidity, increased heart rate). 

If you are experiencing any side effects after consuming Cymbalta, make sure you consult your physician for proper management and avoid abrupt discontinuation of the drug, as it can cause withdrawal symptoms and worsen your condition. 

What are the other medications that influence serotonin levels? 

There are many drugs which can influence the levels of serotonin in the body, such as: 

  • Selective serotonin reuptake inhibitors (SSRIs): citalopram, escitalopram, fluoxetine, paroxetine, and sertraline.
  • Serotonin-norepinephrine reuptake inhibitors (SNRIs): venlafaxine, milnacipran, desvenlafaxine, levomilnacipran. 
  • Tricyclic antidepressants: amitriptyline, amoxapine, nortriptyline, imipramine. 
  • Atypical antidepressants: bupropion, mitrazapine, trazodone. 
  • Monoamine oxidase inhibitors (MAOIs): isocarboxazid, selegiline. 

Concomitant use of antidepressants with stimulants also influences the levels of serotonin and sometimes can cause high levels of serotonin, which can lead to serotonin syndrome. 

In my opinion, Cymbalta does not contain serotonin, but it increases the level of serotonin in the brain, which helps treat symptoms of depression, anxiety, fibromyalgia and chronic pain. 

I would advise you to know your medication before you consume it, and if you are taking Cymbalta to treat your illness, know that abrupt discontinuation of the drug can cause withdrawal symptoms and worsen your condition. Always consult your physician before making any changes to your treatment and if you experience any side effects.

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


Chalon SA, Granier LA, Vandenhende FR, Bieck PR, Bymaster FP, Joliat MJ, Hirth C, Potter WZ. Duloxetine increases serotonin and norepinephrine availability in healthy subjects: a double-blind, controlled study. Neuropsychopharmacology. 2003 Sep;28(9):1685-93. Available from: 


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