As you’re sipping your calming cup of tea before bed, it’s not likely you think of every ingredient swirling in your steaming cup. It’s just tea leaves, right?
But actually, fresh tea leaves contain various compounds, including enzymes, carbohydrates, minerals, pigments and amino acids that are responsible for giving your tea its distinct taste, color and aroma.
L-theanine is just one of those amino acids.
So, what is L-theanine? Most often found in tea and supplements, L-theanine is primarily used to improve mental function. Read on to learn more about how L-theanine works within your body, and the positive effect it can have on your daily life.
How Does L-theanine Work?
L-theanine is a water-soluble, non-protein amino acid, which means it’s not naturally found within the human body. However, it is found organically in nature. More specifically, L-theanine is present in plant and fungal species.
While L-theanine is not a one-stop-shop to easing stress, it may be a great supplement to other treatments, such as talk therapy, yoga or meditation.
In fact, L-theanine is a large component of black, white and green teas and is identifiable by its unique, brothy flavor. However, it’s used in dietary supplements, as well.
When ingested, L-theanine is thought to decrease the “excitatory” brain signals that contribute to feelings of stress and unease. In addition, it may also increase brain chemicals that promote a calming effect.
But how exactly does it do this? L-theanine is able to cross the blood-brain barrier, a highly selective border of cells that separates circulating blood from components of the central nervous system, such as the brain’s neurons.
Since L-theanine can cross this barrier, it’s able to influence serotonin and dopamine receptors — which are responsible for feelings of happiness — within the brain to increase your sense of calmness.
In matcha-dense Japan, where L-theanine was first discovered in green tea leaves, the amino acid has been approved for all foods. Similarly, the United States Food and Drug Administration considers it to be safe.
Benefits of L-theanine
So what does L-theanine do for the body? While there isn’t a worldwide consensus on the health benefits of L-theanine, numerous studies have been conducted that support the theory that L-theanine may improve your:
- Mood – In addition to elevating serotonin and dopamine levels, L-theanine is also thought to increase levels of GABA, or neurotransmitters that work within the brain to regulate your emotions, concentration, alertness and energy.
- Attention span – L-theanine can improve your attention by influencing your brain’s alpha wave activity, which controls your sense of “wakeful relaxation.” Higher levels of alpha waves can help you focus and unwind.
- Cognitive function – When ingested, L-theanine can stabilize cognitive functions disrupted by high levels of stress hormones, specifically decreasing levels of corticosterone.
- Quality of sleep – Because L-theanine works to reduce feelings of stress and unease, it may also promote relaxation and better sleep quality.
- Weight loss – L-theanine may also improve elevated lipid levels, promoting weight loss. It may also stimulate the metabolism, increase levels of fullness and lengthen the amount of time before your hunger returns.
- Immune function – The amino acid may help your body fight off dangerous infections by boosting your immune system and providing anti-inflammatory effects.
While L-theanine is not a one-stop-shop to improving your stress levels, it may be a great supplement to other treatments, such as talk therapy, yoga or meditation.
L-theanine Dosage Recommendations
When incorporating L-theanine into your daily routine or as a dietary supplement, it’s recommended that users start with a smaller L-theanine dosage and work their way up depending on the intended purpose:
- For sleep or stress – 100 mg to 400 mg
- With caffeine – 12-100 mg L-theanine; 30-100 mg caffeine
L-theanine and Caffeine
So why exactly do L-theanine and caffeine get their own category? L-theanine and caffeine are often used in conjunction to improve cognitive performance and increase subjective alertness.
Both L-theanine and caffeine are naturally occurring components in white, black and green teas. So if you’re unwinding from the day with a hot cup of tea or even sipping while on the job, you may benefit from the following:
- Improved visual information processing
- Accuracy when moving between tasks
- Faster reaction time
- Increased focus and attention
- Improved number skills
L-theanine Risks and Side Effects
When taking any supplement, it should be done with caution. However, there are generally no side effects associated with taking L-theanine in teas or supplements. Yet, consuming large amounts of green tea, which contains a significant amount of caffeine, may lead to:
- Stomach discomfort
- Head tension
Women who are pregnant should also avoid consuming anything with high caffeine levels.
Additionally, L-theanine should not be used in combination with certain medications. If you’re at all worried about the implications, it’s best you consult a medical professional.
Difference Between L-theanine and D-theanine
While L-theanine is a unique amino acid found mostly in tea leaves and mushrooms, D-theanine is a different type of amino acid that can actually inhibit the absorption of L-theanine.
However, D-theanine is often difficult to detect, which means some supplements may contain this amino acid unknowingly.
According to a study by Iowa State University, many L-theanine products contain levels of D-theanine, which may decrease the effectiveness of the stress-relieving supplement.
However, most products only contain small amounts of D-theanine.
Where to Find L-theanine
So, what is L-theanine used for and what can you find it in? The same Iowa State study also showed that L-theanine may lower your blood pressure. If you’re looking to get your hands on the amino acid you can find it in:
- Green tea – Theanine was originally found in the leaves of green tea
- Black tea – Some forms of black tea have higher Theanine levels than green tea
- White tea – Almost as equally dense with Theanine as green tea
- Mushrooms – One mushroom, in particular, contains Theanine: Imleria badia, an edible fungus found in Europe and North America
Additional Ways to Increase Relaxation With CBD
CBD, which usually comes in the form of oils, topicals and chewable tablets, works with your body’s endocannabinoid system (a network of receptors found throughout your body) to promote relaxation and a sense of wellness.
While L-theanine is thought to improve your mood and improve your sleep quality, CBD can do much of the same. In fact, L-theanine may be linked to the same system that interacts with CBD: the endocannabinoid system (via the GABA system).
More specifically, the endocannabinoid system works within your body to maintain homeostasis by regulating your body’s stress response. CBD interacts with this system’s receptors. On the other hand, GABA is a neurotransmitter, which can be heightened by L-theanine, that sends messages between your brain and nervous system to tell your body that it’s safe and sound.
Alongside L-theanine, CBD creates a surplus of GABA in the brain, promoting feelings of calmness and ease, in addition to:
- Reducing feelings of nervousness
- Improving mood
- Easing tension
- Promoting overall health, wellness and vitality
Calm Your Body With Zebra CBD
Know that L-theanine may improve your mood, sleep and weight loss while also bolstering your cognitive function and immune system.
With Zebra CBD, you can combine L-theanine with CBD for ultimate relaxation.
More specifically, we offer two stress-fighting products that enlist the help of both:
- Zebra CBD Tension & Stress Tablets – In addition to premium CBD oil made from organically grown hemp, the tablets also combine L-theanine, magnesium and GABA to help relieve stress, unease and nervousness.
- Zebra CBD Sleep Support Tablets – We combine hemp extract, L-theanine, valerian extract, chamomile extract and melatonin to help you improve your sleep with increased levels of tranquility and calmness.
If you’d like to only enlist CBD in your fight against stress, we have you covered there, too. We offer a lineup of premium oils, topical rubs and edibles. Each of our CBD products is made with premium hemp extract that’s naturally and organically grown.
Additionally, our products come with a Label Accuracy Guarantee™ that ensures our CBD has been tested by two certified third-party labs. Every product batch is free of heavy metals, microbial and unnatural pesticides, herbicides and fungicides. We also closely monitor the amount of CBD and THC in each product to ensure label accuracy.
With Zebra CBD, you can rest assured that everything on our products' labels is accurate, including L-theanine.
Trust Zebra CBD for all your CBD needs. For more on other natural supplements, visit our website for information like what turmeric does for your body and elderberry health benefits.
Encyclopedia of Astrobiology. Non-Protein Amino Acids. https://link.springer.com/referenceworkentry/10.1007%2F978-3-642-11274-4_1070
MDLinx. One supplement you should start taking now. https://www.mdlinx.com/article/one-supplement-you-should-start-taking-now/lfc-3252