If you’re feeling drowsy, stressed, or under the weather, you may want to try adding L-theanine to your routine. But what is L-theanine, and are other health benefits associated with it? Here’s everything you need to know about this amino acid.
What is L-theanine?
L-theanine is a non-essential amino acid that is naturally found in tea and certain types of mushrooms [1
]. Non-essential means that your body can produce this amino acid, even if you do not get it from your diet.
L-theanine is best known for improved sleep and cognitive performance, but are there other benefits? Let’s see what science has to say.
Anxiety and stress relief
L-theanine might have the ability to improve stress-related symptoms (such as depression, anxiety, and insomnia). Research indicates that L-theanine may promote mental health in the general population with stress-related ailments and cognitive impairments and reduce feelings of stress and anxiety [2
]. It’s also been found to lower blood pressure in high-stressed individuals [4
When should I take L-theanine for anxiety?
If you have moderately severe anxiety symptoms, research shows you may respond to L-theanine when taken at a dose of 200 - 400 mg for up to 8 weeks. More severe anxiety may require amounts up to 600 - 800 mg/day divided into 200-mg increments spaced over the day [5
L theanine and ashwagandha
is an herb that is commonly used to alleviate stress, anxiety, depression, and insomnia. And since L-theanine has also been shown to help with anxiety and stress, it’s suggested that they can be taken synergistically [7
It’s recommended to speak with your healthcare provider before taking L-theanine and ashwagandha together, as this can help alleviate any contraindications.
Experts have found that people who took L-theanine experienced reduced sleep quality problems and sleep disturbances throughout the night [8
]. Evidence has also shown that L-theanine’s sleep benefits may be amplified when taken with gamma-aminobutyric acid (GABA), a neurotransmitter that improves sleep disturbances [9
]. Furthermore, research suggests that L-theanine may help reduce a person’s heart rate, which can contribute to the feeling of relaxation [10
Studies indicate that taking 450–900 mg of L-theanine/day for eight weeks can yield greater sleep satisfaction, whereas 200 mg of L-theanine twice per day may improve sleep efficiency [11
L-theanine and melatonin
Melatonin and L-theanine are often well-tolerated and can promote a deeper, more restful sleep when taken together. But don’t rush to the store just yet–talk with your healthcare provider to see if this combination is right for you.
Pairing L-theanine with caffeine may help to enhance focus. For example, studies have found that a combination of 97 mg of L-theanine and 40 mg of caffeine could boost cognitive performance and help people focus better during demanding tasks [13
If you want to lose weight, drinking tea may be a good choice. Studies have found that the L-theanine present in green tea creates an umami flavor, which may reduce appetite and aid in weight loss [14
Studies suggest that L-theanine may benefit the ratio of Th1 and Th2 cells, which play an essential role in the immune system [15
]. As such, supplementation might improve someone’s immune health status.
How much theanine should I take a day?
At Elo, we generally recommend 100 mg/day of L-theanine, but this number increases to 200 mg/day for those looking to boost cognition, lower stress, and improve sleep. Because most individuals don’t consume much L-theanine from their diet, supplements can be beneficial.
The best non-supplement sources of L-theanine are green and black teas and certain varieties of mushrooms. If you’re looking to get L-theanine through dietary sources, here is a brief breakdown of the levels present in these foods.
One cup (200 mL) of green tea contains around 8 mg of L-theanine [17
One cup (200 mL) of black tea contains around 24 mg of L-theanine [17
The mushroomBoletus badius
has an L-theanine content of 17 mg/L [18
Is it better to take L-theanine in the morning or at night?
Since L-theanine can help improve sleep quality, taking it at night is recommended. However, since tea can contain caffeine, it’s recommended that you opt for a caffeine-free or herbal option before bed.
While L-theanine is generally safe and well-tolerated, it may lower blood pressure in some people and increase the effects of antihypertensive drugs [19
]. Furthermore, since there is a lack of information regarding the safety of L-theanine, pregnancy, and breastfeeding, it’s best to avoid taking it during this time.
L-theanine is most often known for its positive impact on relaxation, but it’s also been found to be beneficial for sleep, anxiety symptoms, stress relief, weight management, and immunity. You can obtain L-theanine through green and black tea, certain mushrooms, and supplements, and while this amino acid is generally safe and well-tolerated, you should speak with your healthcare provider before adding it to your supplement routine.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.