L-Theanine is one of the most popular nootropic-like compounds on the market today. Often stacked with caffeine, L-theanine is popular with everyone from students to entrepreneurs. Here’s our L-theanine guide.
What is L-Theanine?
L-theanine is an amino acid that can purportedly provide anti-stress and anti-anxiety effects (“anxiolytic”). The amino acid is derived from tea leaves.
L-theanine is not common in a standard diet – which is why most of us get our L-Theanine content from supplements and our diet (it’s fond in green tea, for example).
Because L-theanine is thought to weaken the negative side effects of caffeine, it’s often used as part of a stack. “Caffeine plus L-theanine” is one of the world’s most popular nootropic stacks.
Although L-theanine isn’t backed by overwhelming scientific evidence, it is popular within the nootropics community for its ability to induce a relaxed state of mind without unwanted drowsiness.
Tea is the most widely-consumed beverage in the world – and it’s been that way for centuries (possibly even millennia). Despite that fact, L-theanine wasn’t actually isolated until 1949. By 1964, Japan had approved the “unlimited” use of L-theanine in foods like chocolates, soft drinks, and herbal teas. L-theanine, however, was not permitted to be included in baby food. When added to foods and beverages, L-theanine is thought to provide a unique brothy or savory taste and flavor.
Although L-theanine is primarily derived from green tea, it is also found in smaller amounts in black tea. Green tea can contain anywhere from 5mg to 64mg of green tea per cup.
Benefits of L-Theanine
L-theanine is mostly prized for its complementary benefits with caffeine. It’s rarely used on its own. Nevertheless, some of the benefits associated with L-theanine usage on its own include:
Reduce Anxiety and Stress
The primary benefit of L-theanine is to reduce your anxiety and stress. It inspires a feeling of relaxation without the sleepiness typically associated with relaxation-inducing drugs.
These effects have been demonstrated in three major studies thus far, including this 2004 study that measured the acute effects of L-theanine in comparison with a popular conventional relaxant (alprazolam). Researchers concluded that “the results showed some evidence for relaxing effects of L-theanine during the baseline condition on the tranquil-troubled subscale of the VAMS.” However, researchers cautioned that: “the findings suggest that white L-theanine may have some relaxing effects under resting conditions, neither L-theanine not alprazolam demonstrate any acute anxiolytic effects under conditions of increased anxiety.”
In a 2011 study, researchers sought to determine L-theanine’s effect on attention and reaction time. The study concluded that participants experienced better attention and reaction time, but that “no significant differences were noticed among subjects with a minimal anxiety propensity.” At first read, this doesn’t sound like a good study for L-theanine fans. However, this study shows that L-theanine had similar effects to a popular anxiolytic – there just weren’t any significantly different effects between the two.
In a 2003 study performed at St Mary’s Hospital in Seoul, South Korea, researchers examined the effects of L-theanine on 20 healthy male volunteers between ages 18 and 30. By the end of the study, researchers concluded that “the results of this study suggest that L-theanine containing tablets promote the release of alpha waves related to mental relaxation and concentration in young adult males.”
The final linked study, the 2003 study, provides the best evidence for the relaxation-inducing effects of L-theanine. The second linked study, the 2011 study, showed that L-theanine did not have a significant difference from a traditional anxiolytic. And the first linked study showed that L-theanine has relaxing effects under some conditions.
Ultimately, L-theanine has repeatedly demonstrated scientific evidence for inducing relaxation. Three major studies have demonstrated these effects, although more studies with more subjects are required to make these results definitive.
Boost your Mood and Concentration
L-theanine hasn’t demonstrated the same scientific evidence at boosting mood and concentration. The only major scientific study on L-theanine’s effect on mood and concentration is this study from 2011, which was also linked above under the “relaxation” section.
This study illustrated two things: L-theanine has relaxation effects similar to a popular anxiolytic. And, more importantly, L-theanine showed that the compound had a “pronounced effect on attention performance and reaction time response in normal healthy subjects prone to have high anxiety.”
The study involved 18 healthy university student volunteers. The students were separated into two groups: one group was deemed to be prone to high anxiety, while the other group was deemed to be a low anxiety risk. Participants received L-theanine or a placebo in a double blind repeated measurement design protocol study. Visual attention tasks and auto response tests were performed 15 to 60 minutes after ingestion.
By the end, researchers had concluded that “The results demonstrate the significant enhanced activity of alpha bands, descending heart rate, elevated visual attentional performance, and improved reaction time response among high anxiety propensity subjects compared to a placebo.”
So the main catch of this study is that all participants that demonstrated better focus already had high anxiety. It’s unknown if participants without pre-existing high anxiety would enjoy the same boost to attention performance and reaction time.
It’s also important to note that the study involved just 18 people separated into two groups, with half of each group taking a placebo and the other half taking L-theanine.
How Does L-Theanine Work?
L-theanine is thought to work by raising levels of dopamine in the body. Dopamine is the neurotransmitter that is naturally released by the body when it wants us to feel relaxed: like when we’re having sex, eating, or just relaxing.
The exact way in which L-theanine raises dopamine is not well-known.
However, we do know that L-theanine crosses the blood-brain barrier. Those who take L-theanine demonstrate effects within 30 minutes of ingestion and these effects last for up to 5 hours after administration.
How to Use L-Theanine
The typical L-theanine dose is 200 to 250mg. These are the doses used in the anti-anxiety studies listed above.
However, those who stack L-theanine with caffeine instead of taking it by itself often take a lower dose: say, 50 to 100mg of caffeine with 100 to 200mg of L-theanine. You should maintain a 1:2 caffeine to L-theanine ratio.
You can also get L-theanine from drinking green tea or black tea. See below for details on how much to take.
How Much L-Theanine is in Green Tea and Black Tea?
You can create your own natural caffeine plus L-theanine stack by drinking green tea – although you’ll need to drink a significant amount of green tea to reach the same levels as a standard caffeine + L-theanine stack.
There are about 20mg of L-theanine in a cup of black tea.
Green tea can have anywhere from lows of 5mg of L-theanine in each cup to as much as 46mg per cup (Gyokuro and Matcha green tea, for example, are particularly popular for their high L-theanine content).
Both black tea and green tea have the same approximate caffeine ranges, with amounts ranging from 14 to 61mg per cup.
How to Buy L-Theanine
You can purchase L-theanine from all major nootropics retailers.
L-theanine is typically fairly cheap. Powder City, for example, sells L-theanine capsules at the following prices:
— 30 Capsules: $3.95
— 90 Capsules: $9.99
Each capsule contains 200mg of L-theanine.
Conclusion: Who Should Use L-theanine?
L-theanine isn’t backed by overwhelming scientific evidence – but the same can be said about most nootropics.
The important thing to note is that L-theanine has demonstrated anti-anxiety effects in three major scientific studies to date. It has also been shown to boost mood and concentration – although the one study that exhibited these benefits was small in scale.
The biggest problem with L-theanine studies to date is that they rarely study the effects of stacking L-theanine with caffeine – which is what most people do with L-theanine. For that reason, your best evidence for L-theanine comes from anecdotal evidence online – and this obviously isn’t the most scientific way to assess the effects of L-theanine.