Interaction Details

Sertraline is classified as belonging to the following category: Serotonergic Drugs

Clinical studies regarding the effects of L-theanine on serotonin levels are conflicting. Some studies suggest it can increase serotonin levels in the brain while others report that it may decrease them. Nevertheless, there have been no reports of l-theanine being a causative agent in serotonergic-related side effects or serotonin syndrome.

Interaction Rating


Likelihood of Occurrence


Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Pharmacist Analysis

Studies suggest that L-theanine may act as a GABA agonist and increase GABA levels in the brain, leading to relaxation, and potentially influencing changes in levels of dopamine and serotonin. However, animal studies report that L-theanine has been shown to decrease serotonin concentrations in the brain and may enhance the degradation of serotonin.

Overall, there isn't consistent evidence to make a reliable determination on how L-theanine could affect serotonin levels overall. Regardless, there are no case reports or clinical studies showing it carries a risk of causing serotonin-related side effects and studies have even utilized it for those taking antidepressants with no reported adverse reactions.


  • Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis. Nutr Rev . 2014 Aug;72(8):507-22
  • Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr . 2017 Apr;29(2):72-79
  • Theanine-induced reduction of brain serotonin concentration in rats. Biosci Biotechnol Biochem . 1998 Apr;62(4):816-7

Theanine Overview

Theanine Theanine, often referred to as L-theanine as that is the predominant isomer of theanine, is an amino acid commonly found in tea leaves, particularly in green tea. It is purported to increase levels of GABA, serotonin, and dopamine in the brain, which can help to reduce stress and anxiety. L-theanine may also promote a sense of calm and improve overall well-being. Some studies have also suggested that it may improve cognitive function, although more research is needed. Most reported drug interactions with theanine are due to its sedative effects.
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Sertraline Overview

  • Sertraline is used to treat depression, obsessive-compulsive disorder (bothersome thoughts that won't go away and the need to perform certain actions over and over), panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks), posttraumatic stress disorder (disturbing psychological symptoms that develop after a frightening experience), and social anxiety disorder (extreme fear of interacting with others or performing in front of others that interferes with normal life). It is also used to relieve the symptoms of premenstrual dysphoric disorder, including mood swings, irritability, bloating, and breast tenderness. Sertraline is in a class of antidepressants called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amounts of serotonin, a natural substance in the brain that helps maintain mental balance.

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Theanine - More Interactions

Theanine interacts with 557 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.

Major The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur.
Moderate Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur.
Minor Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction.
Unknown No interactions have been reported or no interaction data is currently available.

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Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Drug descriptions are provided by MedlinePlus.

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