L-Theanine vs L-Tyrosine: Comparing Benefits, Side Effects & More

by Kat Austin November 23, 2022 6 min read

L-Theanine vs L-Tyrosine: Comparing Benefits, Side Effects & More - Vida Optima™

L-Theanine and L-Tyrosine are both amino acids, and you’ll commonly see the two paired together in nootropic stacks and other wellness supplements. They actually have pretty different effects, however, so understanding the difference in L-theanine vs L-tyrosine is crucial to understanding whether you should be taking one or the other (or possibly both) to reach your own wellness goals.

We’ll break it down, plus give you some insight on why these two amino acids are usually paired up in supplements designed to boost your mood and mental performance. Here’s what you should know:

Looking for a tasty product that pairs both into a well-balanced nootropic stack? We recommend checking out Lucid Super Coffee.

Table of Contents
What is L-Tyrosine?
What is L-Theanine?
L-Tyrosine vs L-Theanine: What’s the Difference?
Benefits of Taking L-Theanine and L-Tyrosine Together
Risks Associated L-Tyrosine/L-Theanine Stacks
L-Tyrosine vs L-Theanine: Which is Best?

Key Takeaways

  • L-theanine and L-tyrosine are both naturally occurring amino acids.
  • Both may positively impact the nervous system to provide cognitive and physical benefits.
  • They have very different effects, but pairing them together may reap the most balanced benefits.
  • Both L-tyrosine and L-theanine are thought to be safe, with no toxicity levels reported.

What is L-Tyrosine?

L-tyrosine is the form of the amino acid tyrosine that is most commonly used in supplements. It’s technically a non-essential amino acid, meaning a healthy body makes it on its own and you don’t need to get it from food. However, the body may not produce enough tyrosine to deal with increased stress levels, and supplementing with tyrosine has been linked to numerous benefits.

Benefits of L-Tyrosine

In the body, tyrosine is a precursor to dopamine. Dopamine is excitatory–a “happy hormone” associated with mood, focus, and motivation. Low dopamine is one of the primary causes of depression, concentration impairments (like ADHD), poor sleep, and various other mental health related issues.

Supplementing with L-tyrosine has been linked to numerous benefits, although researchers still have a lot to learn about what L-tyrosine can do. Still, we have some evidence to help us understand some of L-tyrosine’s primary potential benefits, like:

  • Improved cognition
  • Improved athletic performance
  • Mood regulation
  • Stress reduction

A 2015 study touches on L-tyrosine’s potential benefits for improving cognition. In this study, tyrosine supplementation was found to help the brain function even in tasks that invoke stress and require high mental endurance. Another study found that tyrosine supplementation increased focus and alertness even after exhaustive exercise, although the trial size was small so more information is needed.

One other small study found that tyrosine supplements may even help protect against cognitive decline during certain extreme physical conditions as well. The study found that subjects taking tyrosine supplementation experienced less cognitive decline when exposed to severe cold conditions compared to the placebo group.

A 2011 study found that taking a tyrosine-enriched beverage while exercising in hot conditions may boost endurance. Because of its potential ability to reduce stress, some people believe that L-tyrosine can help increase endurance during competitive activities, such as competitive sports.

What is L-Theanine?

L-theanine is the most common form of theanine used in wellness supplements. L-theanine is an amino acid that is often found in tea leaves and certain superfood mushrooms. In fact, it's one of the primary reasons that some teas, like green tea, have been linked to such a wide array of health benefits.

Benefits of L-Theanine

Theanine is thought to mimic the actions of glutamine in the body, an important neurochemical responsible for regulatory functions within the Central Nervous System.

More specifically, glutamine is an amino acid that is primarily responsible for GABA production. GABA is a neurotransmitter responsible for inhibiting excitatory signals, including neuronal functions induced by stress and fear. Therefore, by producing GABA, glutamine (and therefore theanine) can help support a healthy stress response and promote relaxation.

According to current research, supplementing with L-theanine may offer many of the following benefits:

  • Increased relaxation
  • Mood regulation
  • Improved sleep
  • Increased focus

Although most human trial sample sizes have been small, L-theanine’s effects on both cognition and stress have been heavily researched. A small 2011 study, for instance, found that L-theanine had a pronounced effect on attention and reaction time response in healthy adults who are prone to anxiety.

In a 2019 randomized controlled trial involving 30 healthy adults, researchers found that daily L-theanine supplementation decreased stress-related symptoms (involving depression, anxiety, and sleep) and increased cognition scores (involving verbal fluency and executive function). Ultimately, the authors concluded that L-theanine was safe and well-tolerated and may be a “suitable nutraceutical ingredient for improving mental conditions in a healthy population.”

One study involving 91 people found that a combination supplement of green tea extract (360mg) and theanine (60mg) helped to improve selective attention in subjects with mild cognitive impairments (such as ADHD).

A model comparing the molecular structure of L-theanine vs L-tyrosine

L-Tyrosine vs L-Theanine: What's the Primary Difference?

Both L-Tyrosine and L-Theanine are amino acids that may help to regulate neuronal functions, but there is a major difference between the two. In fact, the two have nearly opposite functions–one is excitatory and one is inhibitory. While L-Tyrosine can have effects that are stimulating and motivating, L-theanine has soothing, relaxing effects.

You may have noticed, though, that both of these aminos acids share one potential benefit–increasing cognitive performance. This is the reason you can often find both L-Theanine and L-Tyrosine in nootropic supplements designed to improve cognitive functions–and the two come together to provide some uniquely balanced effects. Here's how:

Benefits of Taking L- Theanine & L-Tyrosine Together

When taking Theanine and Tyrosine together, you get to enjoy the unsure benefits of each amino acid on its own. However, the two provide a foundation for each other to increase the cognition-enhancing effects you can get from either supplement.

L-Tyrosine may help to promote motivation and impulse control. L-Theanine may help to reduce stress (distraction) and provide a calm, relaxed state that makes focus more obtainable. Since focus requires both motivation and clarity, this is a winning combination. Plus, the addition of caffeine can help to provide energy and endurance. This synergistic benefit is the concept behind nootropic stacks, a method of "biohacking" your brain to achieve your best performance levels.

An example of an L-tyrosine and L-theanine stack in powder and capsule form.

Are there any risks associated with L-Theanine/L-Tyrosine stacks?

Both tyrosine and theanine are found in foods we consume daily, like mushrooms, tea, nuts, and even meat. There have been no serious risks associated with supplementing with either of these amino acids, and the two have no adverse reactions with each other.

Most research describes these compounds as “safe and well tolerated,” and no side effects have ever been noted, even from long term use. In fact, these two supplements may even help to negate the risks associated with other popular brain-boosting supplements, like caffeine.

Of course, if you do experience any side effects when taking either supplement, stop taking them immediately and consult your doctor. It’s always possible to have a reaction to wellness supplements as many contain additional ingredients.

To learn more, you may want to read:

L-Theanine vs L-Tyrosine: Which is best?

If you’re trying to decide which of these amino acids is the “better” supplement–there’s really no clear winner. Neither L-Tyrosine or L-Theanine have any outright advantages over the other. It really just depends on what you need from your supplementation routine.

In most cases, a combination of the two can be most helpful. Remember, these are amino acids that are naturally occurring in foods and that emulate amino acids that naturally occur in your body. You aren’t likely to do any harm by adding both to your wellness regimen.

For best results, you may want to incorporate both of these alongside a more diverse nootropic blend. Taking L-tyrosine and L-theanine with Lion’s Mane, Chaga, 5-HTP, Alpha-GPC, or other nootropics may provide enhanced synergistic benefits. Ultimately, the supplements you choose should directly reflect your wellness goals.

You may also want to read:


  1. “Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands--A review” https://pubmed.ncbi.nlm.nih.gov/26424423/
  2. “The effects of acute and prolonged CRAM supplementation on reaction time and subjective measures of focus and alertness in healthy college students”https://www.tandfonline.com/doi/full/10.1186/1550-2783-7-39
  3. “Tyrosine supplementation mitigates working memory decrements during cold exposure” https://www.sciencedirect.com/science/article/abs/pii/S0031938407001722?via%3Dihub
  4. “Oral tyrosine supplementation improves exercise capacity in the heat” https://link.springer.com/article/10.1007/s00421-011-1921-4
  5. “Effects of l-theanine on attention and reaction time response” https://www.sciencedirect.com/science/article/pii/S1756464611000351
  6. “Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836118/
  7. “A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study” https://pubmed.ncbi.nlm.nih.gov/21303262/

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