L-theanine is an amino acid found in tea. Although L-theanine is associated with several health benefits, no research confirms if it is effective in treating bipolar disorder.
L-theanine is a water-soluble amino acid found in green and black teas. It is also available as a supplement.
The Food and Drug Administration (FDA) has given L-theanine a GRAS status, which means that it is generally recognized as safe. However, if you are currently on any medications to manage bipolar disorder, you should talk with your doctor before trying L-theanine.
If you are on sedating medications
Some bipolar medications have a sedating effect. While it is not a sedative itself, L-theanine can intensify this effect. If you are on sedating medications or are not sure if your medications are sedating, it is important to talk with your doctor before trying L-theanine.
Currently, there is no definitive research that confirms if L-theanine is an effective treatment for bipolar disorder.
One 2021 case study involving a 26-year-old woman with bipolar disorder, generalized anxiety disorder, and post-traumatic stress disorder (PTSD) found that a personalized nutrition intervention — which included L-theanine — was able to improve mood.
However, due to the lack of participants and multiple variables in this study, a conclusion on the effect of L-theanine specifically cannot be drawn.
While there is little research on the connection between L-theanine and bipolar disorder in particular, it has been shown to have beneficial effects on other mood disorders.
A 2024 review of studies found that L-theanine reduced symptoms in individuals with:
While more research needs to be done on L-theanine’s effects on bipolar disorder, it does have some general health benefits.
According to a 2022 review, L-theanine exerts the following effects:
- antioxidant
- anti-inflammatory
- anticancer
- antiobesity
The same study also suggests that L-theanine protects several organs, including:
- brain
- heart
- liver
- kidneys
L-theanine may also help regulate your metabolism.
Recipes with L-theanine
If you have bipolar disorder, you
As with any supplement, it’s important to watch out for any potential side effects. Studies in which the participants took L-theanine supplements have reported minor side effects, such as:
- nausea
- vomiting
- abdominal pain
- diarrhea
- headache
- loss of appetite
- irritability
If you experience any of these side effects, let your doctor know. They may advise you to stop taking L-theanine as a supplement.
Additionally, consuming a large amount of tea may cause you to feel anxious or have trouble sleeping.
Currently, there is no research that supports that L-theanine has a definitive beneficial effect on bipolar disorder. However, L-theanine may have a positive effect on other mental health conditions, including schizophrenia, anxiety disorders, and PTSD.
L-theanine also has general health benefits such as regulating your metabolism and protecting your organs.
L-theanine naturally occurs in low levels in tea. If you are interested in taking L-theanine as a supplement, talk with your doctor before starting. They will be able to advise you on whether it is appropriate by taking your health needs into account.