L-Theanine vs. L-Tyrosine: Which Is Better for Stress Reduction?

Did you know that L-Tyrosine and L-Theanine are two compounds widely researched for their potential role in stress management? Each compound has its own advantages, limitations, and uses, and they are intended for different user groups.

Therefore, many people interested in reducing stress and relaxing the mind do not know which type is best for them. In this article, we will analyze the science behind these two supplements to help you make an informed decision. Read on to learn more.

Comparison Table of L-Tyrosine and L-Theanine

About L-Theanine

What is L-Theanine?

L-Theanine is an amino acid commonly found in certain types of tea (like green tea, black tea) and some types of mushrooms. L-Theanine is the most common and bioavailable form of Theanine, meaning the human body can easily absorb and metabolize it [1, 2].

L-Theanine works by directly influencing the nervous system in the brain, helping transmit "messages" from the brain to different organs, allowing the body to respond more quickly and efficiently.

L-Theanine has been studied for its influence on neurotransmitters such as GABA, dopamine, and serotonin. Thanks to this mechanism, L-Theanine is known as a natural remedy — promoting mental clarity and reducing excessive stress [1, 2].

Many people turn to L-Theanine when they feel stressed by drinking a warm cup of tea or eating foods made from mushrooms. However, the amount of L-Theanine obtained this way may not always meet the body’s daily needs — it could be too much or too little — leading to inconsistent effects.

As a result, many choose to supplement with L-Theanine in the form of dietary supplements, where each capsule contains a precise dose of L-Theanine.

Typically, just 1–2 capsules a day (depending on the dosage provided by the manufacturer) is enough to meet daily requirements. Additionally, L-Theanine is generally well-tolerated based on current research, though individual experiences may vary.

L-Theanine Health Benefits

There’s been some debate over whether L-Theanine truly benefits human health. Some people report feeling more relaxed, alert, and productive after consuming tea containing L-Theanine.

On the other hand, some experience dizziness, fatigue, and lightheadedness after drinking the same tea. To clarify these mixed reactions, let’s take a look at some scientific studies demonstrating the health benefits of L-Theanine:

• In the study "GABA and L-Theanine Mixture Decreases Sleep Latency and Improves NREM Sleep" by Suhyeon Kim et al. (2019), researchers confirmed that a GABA/L-Theanine mixture (100/20 mg/kg) improves sleep quality and shortens the time it takes for the brain to enter deep sleep. Better sleep quality results in greater alertness and overall well-being [3].
• Another study, "Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial" by Shinsuke Hidese et al. (2019), demonstrated that taking L-Theanine (200 mg/day) for four weeks significantly reduced stress symptoms. This nutrient also showed positive effects on patients suffering from major depressive disorder by soothing mental distress and minimizing stress levels [4].

To validate the benefits that people are experiencing from using L-Theanine, we reviewed user discussions on Reddit*. After a period of gathering information, we compiled a list of outstanding results that many people have noticed when using L-Theanine in a highly discussed topic.

L-Theanine Side Effects

Although L-Theanine is considered a safe substance to improve concentration and reduce stress for humans, some people experience headaches, dizziness, nausea, diarrhea, etc. For example, in the case of Pristine_Door3297, he had to deal with insomnia for many years, despite trying many ways but with no success.

After learning about L-Theanine, he considered taking 400 mg/day (equivalent to 1 pill) and found that he fell asleep very quickly (20 - 30 minutes instead of 60 - 90 minutes as before).*

Although it was so good, he found that he had frequent nocturia after taking L-Theanine. This had never happened before. Moreover, he often had headaches and fatigue even though he slept more than usual.*

With this story, many comments below also shared similar problems. But most of us find that when taking L-Theanine, they drink more water than usual at night. That is why they have to urinate frequently at night. 

In addition, if using L-Theanine as a must-have measure to go to sleep, they will accidentally become dependent on functional foods. This is not good at all.

Along with some other cases, they find that using L-Theanine makes their mind become dull. They are always in a state of sleepiness even though they have slept more at night. Perhaps, this is the phenomenon of "brain fog" when using too much L-Theanine or not?

That is why there are two schools of opinion, in which some people oppose depending on supplements to sleep, thinking that it can cause psychological dependence. But others think that sleep is more important, as long as the right method is found.

Therefore, when using L-Theanine, note that using high doses of L-Theanine (over 500 mg/day) is not recommended. At the same time, it should only be used when prescribed by a doctor and should not be used continuously for many years, but should be used temporarily for a while and then stopped.

About L-Tyrosine

What is L-Tyrosine?

L-Tyrosine is an amino acid derived from phenylalanine and serves as a precursor to catecholamines — hormones that help the body sense heat, cold, pain, and stress [8].

In addition to its basic role in supporting muscle growth, L-Tyrosine also promotes the production of essential enzymes, thyroid hormones, and melanin. This contributes to better physical health, alertness, and an overall positive mood [5, 6].

While the human body can naturally produce L-Tyrosine, this ability declines with age, potentially leading to insufficient levels. To maintain adequate levels, you can include L-Tyrosine-rich foods in your diet, such as dairy products (like cheese), soy products, avocados, and nuts [5, 6].

However, the amount of L-Tyrosine obtained from food may sometimes fall short of the body’s daily requirements. Additionally, improper consumption (like eating too much or too little or combining L-Tyrosine-rich foods with those that inhibit absorption) can reduce the body's ability to optimally absorb this amino acid.

This raises the question: Is there an easier and safer way to supplement L-Tyrosine? The answer is yes. Dietary supplements offer a convenient and effective way to meet your daily L-Tyrosine needs. For optimal results, taking 150 mg/kg of body weight for three months can help unlock this nutrient’s full benefits [6].

L-Tyrosine Health Benefits

Ever wondered why L-Tyrosine is gaining so much popularity? It’s because of the remarkable benefits it offers. Specifically, L-Tyrosine may help people regain energy, mental clarity, and stress relief.

This is due to its ability to stimulate the production of dopamine and norepinephrine — hormones that can rapidly deplete when you experience excessive stress. This effect was demonstrated in the study "Behavioral and Cognitive Effects of Tyrosine Intake in Healthy Human Adults" by Adrian Hase et al. (2015) [7].

Additionally, Simon N. Young’s study "L-Tyrosine to Alleviate the Effects of Stress?" confirmed that L-Tyrosine may support cognitive performance under stress when taken at a dosage of 2g/day for five consecutive days. Moreover, L-Tyrosine has been studied for its role in cognitive function and mood support, but more research is needed.

L-Tyrosine Side Effects

L-Tyrosine supplements are recognized as safe by the U.S. Food and Drug Administration (FDA) [5]. However, they may interact with certain medications, such as monoamine oxidase inhibitors (MAOIs), potentially leading to adverse health effects.

Additionally, taking L-Tyrosine in excessive doses can cause symptoms like nausea, headaches, fatigue, and heartburn [6].

This unfortunately happened to Accurate_Mud9385, a Reddit user who participated in the discussion. After using the product, although the user could sleep better for 1 hour instead of having to toss and turn for a long time like before, he was not very alert when he woke up.

It felt like he was sleeping for hours and his body was sick. In addition, the user also felt a slight headache but it was not really clear whether the cause was due to using too much functional food or something else [13].*

Not only that, according to the information we collected, there were also quite a few people who advised that although the nutrient L-Tyrosine is good, it is only beneficial when the body is really deficient.

If you are not deficient in L-Tyrosine, daily supplementation may not provide additional benefits and could lead to unwanted effects. Because, instead of bringing positive benefits as researched, the product also leads to many problems.

For example, too much Tyrosine can increase norepinephrine and adrenaline, causing stress, insomnia, and anxiety. Therefore, users are advised to use it in short cycles (a few months or so and then stop as directed by a doctor) or only when necessary (for example, when sleep deprived or exhausted).*

After learning about the benefits and side effects of L-Theanine and L-Tyrosine, you might be wondering which one is better for long-term stress relief. If you’re struggling with prolonged stress and can’t decide which supplement suits you best, keep reading — we’ll help you determine which one aligns better with your specific needs.

L-Theanine vs. L-Tyrosine: Which Is Better for Stress Reduction?

Although both L-Theanine and L-Tyrosine are amino acids that directly impact brain function, their mechanisms and effects differ significantly. To choose the most suitable one for you, let’s take a closer look at how each works:

L-Theanine has been studied for its potential role in promoting relaxation by influencing brain wave activity. Research suggests that it may help support a calm and focused state. Many individuals report experiencing a sense of relaxation and improved concentration after taking L-Theanine, though individual responses may vary.

As for L-Tyrosine, the active ingredient has the ability to stimulate the production of neurotransmitters necessary for clarity and concentration such as dopamine and norepinephrine.

This is similar to the feeling when you use a little tea or coffee in the morning to help increase maximum concentration. Therefore, the level of substances that appear when the brain is too stressed (such as cortisol) is reduced, replaced by substances that are good for the brain.

Depending on your wellness goals, you may choose a supplement that aligns with your needs. That said, whichever you choose, it’s essential to stick to the recommended dosage and avoid overuse in an attempt to see quicker results — as this could lead to unwanted side effects.

What is the Recommended Dosage for L-Theanine and L-Tyrosine?

L-Theanine: A daily dose of up to 900 mg/day for 8 consecutive weeks has been shown to be safe. However, if you’re already taking L-Theanine in supplement form, it’s best to limit your intake of L-Theanine-rich foods like green tea, black tea, and mushrooms to avoid excessive consumption [2].

L-Tyrosine: For L-Tyrosine, the recommended dosage is 150 mg/kg/day. It’s typically available in capsule or tablet form, and you should carefully follow the manufacturer’s guidelines on when and how to take it to ensure safety and effectiveness [6]. Following recommended dosages may support cognitive function, but individual results may vary.

Is it Okay to Take L-Theanine and L-Tyrosine Together?

Many people wonder if combining L-Theanine and L-Tyrosine — both known for their incredible benefits — could enhance cognitive performance and completely eliminate stress. But is this combination safe? Are there any risks? And if it’s safe, what’s the ideal daily dosage for each?

According to the study "Impact of L-Theanine and L-Tyrosine on Markers of Stress and Cognitive Performance in Response to a Virtual Reality-Based Active Shooter Training Drill" (Matthew J. McAllister et al., 2024), consuming L-Theanine and L-Tyrosine together may offer better stress reduction compared to taking them individually, although the effects might not be immediately noticeable with short-term use.

The study also found that both compounds enhance each other’s benefits without interfering with their individual functions [9].

However, there’s still limited research on the optimal dosage for combining these two supplements and how long they can be safely taken together. Therefore, if you’re considering using L-Theanine and L-Tyrosine to boost cognitive function, it’s essential to consult a doctor or a certified nutritionist.

They can help create a safe and effective supplementation plan tailored to your needs. Additionally, since both compounds can interact with certain medications, professional advice is crucial before starting this combination.

Conclusion

Based on the information shared in this article, it’s clear that L-Theanine and L-Tyrosine offer significant benefits for cognitive function, stress management, and overall well-being.

However, they support brain health in different ways that L-Theanine calms the nervous system, promoting relaxation and focus, while L-Tyrosine stabilizes mood and enhances mental clarity by balancing key brain chemicals like dopamine and norepinephrine.

So which one suits you best? Are you looking for relaxation, or do you need to rebalance your serotonin levels and improve focus? Understanding your health needs and consulting a doctor or nutritionist will help you make the best choice.