Does L-Tyrosine Improve Cognitive Function? | Scientific Evidence and Studies

Many of us could use a little help throughout the day. Whether it’s making it through yet another Zoom meeting, or balancing too many tasks for not enough hours in the day, most of us face some challenges that seem like we’re not quite ready for.

It’s no surprise, then, that the Nootropics market is expected to reach nearly $30 Billion in the next few years. Nootropics, or “smart drugs” can be helpful for everything from memory to attention–or, they could be complete bunk. My purpose with this article–with my whole website–is to help people make informed decisions based on actual science. So here, I’ll look at one of the most popular Nootropic ingredients, Tyrosine, to see if it actually works.

Key Takeaways:

  • L-Tyrosine is an amino acid that is essential to the production of neurotransmitters, such as dopamine.
  • Tyrosine is available in many foods, but taken with vitamins and Copper can help its efficacy.
  • Some studies indicate, however, that supplement Tyrosine may prevent healthy brain aging, and may only help with proper emotional response.

  • Other data, including those used by the US military, indicate that Tyrosine is helpful for cognitive performance under extreme stress.

What L-Tyrosine Is

According to none other than Mount Sinai hospital systems, Tyrosine is necessary for almost every protein in our bodies–from hormone production to the development of the transmitters that make our brains work. It can be taken as a supplement, or found in many common foods, such as poultry and fish, nuts and seeds, and dairy products.

Given its pivotal role in so many functions of the human body, it’s no wonder scientists from many fields have sought to identify the benefits of supplementing with it on a daily or acute basis. We’ll focus on the cognitive benefits for the rest of this article.

Some Dubious Results

One of the most rigorous studies I could find came out of the Netherlands, and involved adults aged 61-72 in a series of behavioral tests meant to measure cognitive function. These tests were designed around simple “start” and “stop” commands, to test reaction time in decision making.

The researchers found that Tyrosine helped with what they termed “proactive response slowing,” but not outright stopping an activity. In essence, the more time a participant had to anticipate that their situation would change, the better they reacted with Tyrosine, but there was no change to sudden situation changes.

Lastly, for this study, they found that the positive results such as they were decreased with increased age. They concluded, in part, that Tyrosine may not be the best thing to assist with cognitive function decline due to aging.

Another study wanted to address the purported cognitive load benefits of Tyrosine–results like we’ll see below. Instead, these scientists only found that responses of “anger” increased with Tyrosine supplementation. This may be because Tyrosine is so essential for norepinephrine, an emergency hormone. After all, anger can be a good thing, and properly processing it in extreme stress can free up our minds to perform better. Interestingly, though, in this study they did not see any cognitive improvements with Tyrosine.

Data with Positive Correlation

In a series of unrelated tests, three separate teams of researchers found that Tyrosine improved cognitive function–but specifically in situations of overload. This has interesting applications for people taking Tyrosine as a Nootropic. If a person wants a supplement to help them with high-stress situations, or abnormal multitasking, Tyrosine may be helpful due to its role in hormone production.

In the first study, people were exposed to 90 db levels of sound–equal to a concert, and loud enough to require ear protection in normal circumstances. These researchers found that people taking Tyrosine had improved cognitive scores, and even better diastolic blood pressure readings.

Another study tested participants under sleep deprivation with a battery of repetitive tasks. By the end of testing, participants had been up for over 24 hours, and conducted testing for over seven hours. The test was placebo controlled and blinded. Results showed that Tyrosine had significant improvements in mood and performance for 3 hours after dosage of 150 mg per kg of weight.

Lastly, we have a test where participants had to take a multitasking test. Results support that Tyrosine significantly improves memory of lists to be completed and iteration of tasks–but did not improve arithmetic, visual, or auditory performance.

Significance of Findings

Oftentimes an article from a hospital website, scientific literature review, or advisory panel will end with the tell-tale line “more research is needed.” This is usually an indication that the authors of the article don’t want to stake their own reputation on the data that has already been presented. Whether it’s because the findings are extraordinary, defy conventional logic, or because the test material is something controversial, like an herbal remedy.

With Tyrosine, I encountered this phrase a lot. I did not find it, however, in an article written for the US Military, titled “Food Components to Enhance Performance: An Evaluation of Potential Performance-Enhancing Food Components for Operational Rations”. 

As the title may imply, this was a recommendation to the Pentagon that US forces receive Tyrosine in their rations specifically because it increases cognitive performance under stress.

It may well be noted that if something is effective enough to be included in official recommendations to the brass of the military, it may well be effective enough for the rest of us.


L-Tyrosine has an undisputed effect on the human body. The only real question is whether we get enough of it in our diets–or if supplementing with it can in fact improve cognitive function. While some data may indicate it can impair our ability to age appropriately when we are in our later years, it does seem that there is mounting evidence that it is effective, especially at helping us with mental and memory performance when high-stress situations occur.

People Also Read...

Recent Articles

About the Author

Sam is a passionate health and fitness enthusiast who has been interested in supplements, fitness, and wellness for over 10 years. He is the founder of Great Green Wall - the health and wellness brand and has completed multiple fitness certificates, including personal training and nutrition certifications. Sam has been working as a personal trainer for the past three years and is dedicated to helping his clients achieve their fitness goals and lead healthier lifestyles. He believes that a healthy lifestyle is crucial to a happy and fulfilling life and is committed to sharing his knowledge and passion with others.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}