How L-Tyrosine Can Help Improve Your Mental Performance

L-Tyrosine is a type of amino acid found in the body. The body makes L-Tyrosine from phenylalanine, an essential amino acid. It has been shown to improve mood and focus through many studies. 

Where to find L-Tyrosine

L-Tyrosine can be found in many types of food; some common examples include:

1. Dairy Products: Parmesan Cheese, Ricotta Cheese, and Yogurt
2. Meats: Beef, Chicken, Pork, and Turkey
3. Fish: Tuna, Cod, and Salmon
4. Soy Products: Soy Milk, Soy Sauce, Soybeans, and Tofu
5. Nuts and Seeds: Pumpkin Seeds, Sesame Seeds, Almonds, and Peanuts

History of L-Tyrosine

Since L-Tyrosine is a non-essential amino acid created in the body, it has been around since the dawn of humanity. L-Tyrosine was discovered in 1846 by a German chemist named Justus von Liebig. He discovered it by separating the protein casein from milk. Modern research has started taking a closer look at L-Tyrosine since around the 1980s.

What Does L-Tyrosine Do?

L-Tyrosine helps your body produce neurotransmitters such as dopamine and norepinephrine. It helps keep the mind stable during high-stress situations and sleep deprivation. L-Tyrosine is also needed for thyroid regulation, as it helps create hormones that control metabolism. 

Research-Backed Benefits of L-Tyrosine Supplementation

L-Tyrosine has been shown to have many benefits within clinical studies. Using the studies shown below, here are some of the great benefits of L-Tyrosine.

1) Maintains Cognitive Performance Under Stress and Fatigue

Probably the most famous effect of L-Tyrosine is its ability to boost performance under high stress or sleep deprivation.

In 1995, D.F. Neri and colleagues at the Naval Aerospace Medical Research Laboratory in Pensacola, Florida, were conducting research on a natural supplement that could perhaps counteract the negative effects on performance during sleep deprivation. 

They examined the effects of L-Tyrosine during a night of work with sleep deprivation. The experiment consisted of 20 US Marine males between the ages of 21 and 27. It was a double blind placebo experiment, meaning neither the participants nor the researchers knew who took which. 

The experiment took place between 7:30 PM Thursday and 8:20 AM Friday; participants also stayed up the entire day before. They were also exposed to a 70-decibel low-frequency noise constantly the entire time to simulate a jet engine. This was used to act as a stressor in addition to the fatigue.

The L-Tyrosine was given to the marines through, funnily enough, a banana yogurt. 150mg per kilogram for each of the participants on L-tyrosine. This was given to them at the time of 1:30 am and 3:00 am.

The participants took part in 3 tests; the one we will look at today was the tracking test, which was used to track performance. The tracking test consisted of keeping a cursor on the screen using a trackball. The cursor would drift, and the participants were to recenter it.

The graph above shows the times of the placebo group and the L-Tyrosine group. The scores were nearly identical from the hours of 7:30 PM to 1:30 AM. The goal for each group was to decrease the amount of pixel error, which showed accuracy. However, the placebo group's scores plummeted, while the L-Tyrosine group's scores declined far less dramatically.

How This Could Help Your Jiu Jitsu Training

While I don’t think you should train while sleep deprived, it does show that performance is preserved under high stress and fatigue. According to this study, L-Tyrosine could help performance from decreasing while stressed, which is very common in jiu jitsu training.

2) Supports Working Memory under Stress

A 2015 systematic review by Hase et al. filtered through around 3000 studies and found at least 15 studies that were important to the review. The researchers were supported by the Netherlands Organization for Scientific Research and searched the databases of MEDLINE and PsycINFO.

After a thorough review, they found evidence that clearly showed that L-Tyrosine consistently counteracted the decline in working memory under stress. Meaning, L-Tyrosine helped keep the ability to remember, perceive and process incoming information. This was shown in conditions such as extreme weather and other harsh conditions.

However, it's worth mentioning that the study did not find evidence of the following:

1. Exercise Performance: In everything that they reviewed, they found no credible evidence that L-Tyrosine increased physical performance under stress.
2. Mood: Although there was some evidence showing that it helped mood under stress, it is not enough to draw a clear conclusion. 

It's fair to say that L-Tyrosine has clear benefits to the mind when stressed, which can be a huge plus when training or competing. However, the evidence that it could be used as a general physical performance enhancer is shaky at best.

3) Improving Cognitive Ability while Switching Tasks

Another lesser-known ability of L-Tyrosine is its unique ability to improve cognitive flexibility. Meaning, the ability to not only switch tasks effectively but to determine how long it takes for the brain to prepare for a task. 

Steenbergen et al. (2015) conducted an experiment involving 22 college students at Leiden University in the Netherlands. The participants consisted of all women between the ages of 17-23, all right-handed, and with no cardiac, neurological, or psychiatric disorders. 

This is interesting because the study we looked at above involved 20 US Marine males, so this is the opposite type of group. Just like that study this was a double-blind, placebo-controlled experiment, meaning neither the researcher nor the participants knew who received which substance.

In this experiment, they were testing cognitive flexibility among the women and the effects of L-Tyrosine. Once again, cognitive flexibility is the brain's ability to switch tasks effectively. What makes this experiment different from the others is that there were no stressors or sleep deprivation, which is what a lot of the research around L-Tyrosine is about. 

How the experiment was set up is that they were using a task-switching paradigm. This allowed the researchers to measure the task switching cost between two tasks. The research indicated that L-Tyrosine reduced switching costs, meaning the participants were able to switch tasks more effectively when compared to the placebo group.

The researchers came to the conclusion that this was because of dopamine. L-Tyrosine is the precursor to dopamine; it is needed to make dopamine. Dopamine is known to regulate cognitive flexibility. This means that L-Tyrosine was making dopamine; however, the researchers noted that the body stopped making dopamine after it reached its optimal level. Which means if you take enough L-Tyrosine, the body makes just enough dopamine and discards the rest.

This is a great study to read through, and I highly encourage you to do your own research. Once again, it was very interesting because most studies focus on sleep deprivation or fatigue; this just focused on cognitive flexibility alone.

4) Supports Focus and Attention during Demanding Tasks

L-Tyrosine has also been shown to improve focus and attention during demanding tasks and high cognitive load. This can be very important during training or competition for BJJ, so this is one of the primary reasons people may take a L-Tyrosine supplement.

In another systematic review, just like Hase et al reviewed earlier, Jongkees et al. in 2015 reviewed all available cognitive and behavioral studies on L-Tyrosine to get a clear picture of its abilities and limitations.

What they found was that L-Tyrosine has the unique ability to replenish lost neurotransmitters like dopamine and norepinephrine. This is especially important under demanding tasks or high stress, where dopamine and norepinephrine can deplete far more rapidly than normal. They found that L-Tyrosine has little to no benefit when used during normal stress or a non-demanding task.

The area groups they looked at included individuals who were doing demanding tasks but were stressed, like people who worked in Antarctica and extreme climates, who were usually physically healthy individuals. As well as L-Tyrosine as a possible treatment for psychiatric patients.

In these groups, they found that healthy individuals during demanding tasks or high stress often performed better when taking L-Tyrosine. Effects were even visible up to 7 weeks after extreme cold exposure in the case of the Antarctic residents. However, L-Tyrosine was found not to be an effective treatment for those with psychiatric needs.

This is why L-Tyrosine could be particularly effective during a tournament, when focus and mental sharpness matter most.

5) May help maintain Reaction Time and Psychomotor Performance under Fatigue

This next section will be about arguably the most famous study on L-Tyrosine. Although conducted in 1998 and published in 1999, it had the most realistic scenario and the hardest conditions for L-Tyrosine.

In a study conducted by the Department of Behavioral Sciences of the Royal Netherlands Army, around 32 cadets from the Royal Military Academy volunteered, leaving 16 in the placebo group and 16 in the L-Tyrosine group. However, the course was extremely demanding, leaving only 21 subjects for final analysis, as 11 dropped out due to their injuries.

The reason why this study is often cited as one of the best case uses for L-Tyrosine is because of the conditions the participants went through. Just some of the variables involved in this course included

1. Sustained military operations
2. Sleep loss
3. Psychological stress
4. Heavy physical demands

During this course, they tested both cognitive performance under stress and reaction time using a similar tracking test in Neri et al. They also tested mood; however, L-Tyrosine did not seem to affect the cadet’s mood.

In both tests, the L-Tyrosine group had both superior psychomotor performance and enhanced memory under real stressful conditions, not simulated ones like the other studies. This follows the same findings in the Neri et al study, with the 20 Marines. 

Following this, they came to the conclusion that L-Tyrosine was replenishing norepinephrine. The norepinephrine in the cadets was being rapidly depleted throughout the course. L-Tyrosine was able to give the raw material needed to keep producing norepinephrine. This led to the cadets in the L-Tyrosine group having significantly better performance.

Although a small sample size and a quite dated study, this remains one of the best cases for L-Tyrosine supplementation. 

Safety, Side Effects, and Dosage

L-Tyrosine is most commonly found in foods like meat or dairy. However, some may consider taking it as a supplement for focus during hard exercise. L-Tyrosine is most commonly taken at 500mg to 2g per day for adults. Although rare, some side effects include nausea, fatigue, headaches, and heartburn. 

There are two interactions that you should consider when taking L-Tyrosine:

1. L-Tyrosine may impact how much levodopa the body can absorb. Do not take L-Tyrosine and Levodopa at the same time.
2. L-Tyrosine also increases the amount of thyroid hormones the body produces. Do not take L-Tyrosine while on Thyroid pills, as it could cause complications.

This should not be used as medical advice, as this was not written by a healthcare professional. As always, you should also consult your physician when starting a new supplement, especially if you are pregnant.

Conclusion/TL;DR

L-Tyrosine is a non-essential amino acid made in the body naturally. L-Tyrosine supplementation has been the subject of many studies, and it has reliably shown these benefits:

1. Maintains cognitive performance under stress and fatigue
2. Supports Working Memory under Stress
3. Improves Cognitive Ability while Switching Tasks
4. Supports Focus and Attention during Demanding Tasks
5. Improves Reaction Time and Psychomotor Performance under Fatigue

I highly suggest doing your own research on the topic, as it is very interesting and there are plenty of studies not mentioned in this article. The research makes a compelling case for L-Tyrosine supplementation, even though sample sizes were small. I believe future research will expand our knowledge (and limitations) of L-Tyrosine.

References

• Neri, D. F., Wiegmann, D., Stanny, R. R., Shappell, S. A., McCardie, A., & McKay, D. L. (1995). The effects of tyrosine on cognitive performance during extended wakefulness. Aviation, Space, and Environmental Medicine, 66(4), 313–319. https://pubmed.ncbi.nlm.nih.gov/7794222/
• Hase, A., Jung, S. E., & aan het Rot, M. (2015). Behavioral and cognitive effects of tyrosine intake in healthy human adults. Pharmacology, Biochemistry and Behavior, 133, 1–6. https://pubmed.ncbi.nlm.nih.gov/25797188/
• Deijen, J. B., Wientjes, C. J., Vullinghs, H. F., Cloin, P. A., & Langefeld, J. J. (1999). Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course. Brain Research Bulletin, 48(2), 203–209. https://pubmed.ncbi.nlm.nih.gov/10230711/
• Steenbergen, L., Sellaro, R., Hommel, B., & Colzato, L. S. (2015). Tyrosine promotes cognitive flexibility: Evidence from proactive vs. reactive control during task switching performance. Neuropsychologia, 69, 50–55. https://pubmed.ncbi.nlm.nih.gov/25598314/
• Jongkees, B. J., Hommel, B., Kühn, S., & Colzato, L. S. (2015). Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands — A review. Journal of Psychiatric Research, 70, 50–57. https://pubmed.ncbi.nlm.nih.gov/26424423/
• Therapeutic Research Center. (2026). Tyrosine. In WebMD Vitamins & Supplements.https://www.webmd.com/vitamins/ai/ingredientmono-1037/tyrosine