Everything You Need To Know About L-Tyrosine


L-Tyrosine is an amino acid which is commonly used as a supplement for the purposes of

  • Stress-Reduction
  • Cognitive Enhancement
  • Mood Improvement

Even though these may seem like pretty distinct benefits, they all actually stem from the same basic mechanism.

In this article, I’m going to go over just about everything you could possibly want to know about L-Tyrosine.  By the end of it, you’ll be a Tyrosine expert!

More importantly, though, you’ll be able to make an informed decision as to whether Tyrosine supplementation is a good idea for you.

So, if you’re ready to level up your knowledge on L-Tyrosine, let’s dive right in…

What Is L-Tyrosine?

L-Tyrosine is a non-essential amino acid.

The term non-essential simply means the body is capable of producing Tyrosine on it’s own, so it doesn’t necessarily need to be obtained through your diet.

Tyrosine Molecule

As you can see, L-Tyrosine is relatively simple in terms of chemical structure.

If you were to view it next to the chemical structure of Phenylalanine, the amino acid that Tyrosine can be created from, they would appear pretty similar.

The major chemical difference is that Tyrosine has an Hydroxy group (OH) attached to the 4th carbon in the ring.

Given that it’s one of the simpler amino acids that exists in nature, it makes sense that it would be pretty prevalent in the average diet.

L-Tyrosine can be found in a wide variety of foods.  Some of the more common Tyrosine-rich foods are:

  • Fish
  • Cheese
  • Milk
  • Bananas
  • Avocados
  • Almonds

But it is present in a ton of other foods as well.

Since it is a non-essential amino acid, the body can also produce it by converting the essential amino acid, Phenylalanine.

What Does L-Tyrosine Do?

Although Tyrosine is used for other things throughout the body, it’s most important role is serving as a precursor to neurotransmitters like Dopamine and Noradrenaline.

Dopamine and Noradrenaline belong to a family of related chemicals produced in your body, called Catecholamines.


Understanding the benefits of Tyrosine requires an understanding of Catecholamine synthesis and where Tyrosine fits in within that process.

Catecholamine goes like this:

  1. L-Phenylalanine is converted to L-Tyrosine.
  2. L-Tyrosine is converted into L-Dopa.
  3. L-Dopa is converted into Dopamine.
  4. Dopamine is converted to Noradrenaline.
  5. Noradrenaline is converted to Adrenaline.

Each conversion requires a different enzyme to catalyze it, or set it in motion.

Catecholamine Synthesis

Catecholamine Synthesis

Whether you get your Tyrosine from your diet or not, it’s a critical part of synthesis of Catecholamines, without which, you would cease to function.

The Role Of Catecholamines

There are 3 primary Catecholamines:

  1. Dopamine
  2. Noradrenaline (Norepinephrine)
  3. Adrenaline (Epinephrine)

Although these chemicals are often referred to as neurotransmitters, they’re also hormones.

The term neurotransmitter refers to any chemical that carries messages from cell to cell (neuron to neuron) within the brain.

The term hormone refers to chemicals which carry (chemical) messages throughout the bodys tissues and organs.

Because Catecholamines exert their effects in both the brain and the rest of the body, they are both neurotransmitters AND hormones.

Catecholamine Release (Neurotransmission)

In the brain, the chemical transmission looks something like this:


Those little black dots in the diagram represent Catecholamines being transferred from one neuron (brain cell) to another.  This is how our brain cells communicate.

Catecholamines heavily influence many facets of mental function, including:

You may remember learning about the “fight or flight” response in some point in science class.  As a quick refresher:

The fight or flight response is the name for the set of physiological reaction that occur when we’re exposed sudden stress, either physical or mental.

The name “fight or flight” refers to the evolutionary significance of reacting to stressful, potentially dangerous situations.  In such situations, you would either fight or run away (the flight part).

Catecholamines play a vital role in the fight or flight response.  In dangerous situations, these chemicals induced a state of heightened alertness, mental, and physical energy.

The also cause a number of physiological changes, including the direct stimulation of lipolysis, the break-down of fat.


As you can see, Catecholamines–in this case, Epinephrine (Adrenaline)–enter the fat cell and, through the activation of several enzymes, signaling proteins, and processes, cause the release of fatty acids.

The fatty acids then free to be burned for energy through the process of beta-oxidation.

So, when we talk about the importance of Catecholamines, we’re not just talking about feeling more alert and focused.

They also have powerful fat-burning properties and an adequate supply of these hormones is required for normal fat-burning to occur.

What Are The Benefits Of L-Tyrosine?

L-Tyrosine supplements are marketed for a lot of things, but most the benefits are tied to its role as a “building block” of Catecholamines.

Research has confimed that the process of Catecholamine synthesis is regulated by several enzymes.  Simply consuming a bunch of Tyrosine won’t increase Catecholamine levels outright.

It can, however, be of use in situations when Catecholamine levels would be depleted by supplying the ‘raw material’ for Cateholamine synthesis.

Still, this means L-Tyrosine supplementation has a few noteworthy benefits…

L-Tyrosine And Mood

Since Catecholamines are heavily involved in our stress response, and Tyrosine is a building-block of Catecholamines, it make sense that most of the research on L-Tyrosine supplementation has had much to do with how it can be of use in stressful situations.


Some of that research has zeroed-in on how Tyrosine impacts mood state, since Catecholamines play such a critical role in mood regulation.

L-Tyrosine has been shown to improve mood and performance during long (4.5 hour) cold-exposure.

However, another study found no impact on mood whatsoever.

Overall, it would appear that the effects of L-Tyrosine supplementation on mood are dependent on other variables.

It may help in some people and not at all in others.  It depends on your brain chemistry.

L-Tyrosine And Cognitive Function

L-Tyrosine has been shown to improve cognitive function in human subjects who were kept awake for 24 hours, when cognitive performance would normally decline.

One study in which military trainees were given a Tyrosine supplement (2g/day) performed better on cognitive performance tests after undergoing an intense training regimen.

The researchers in this study concluded that Tyrosine can reduce the impact of stress under “circumstances characterized by psychosocial and physical stress”

These findings are consistent with those in animals which also showed that L-Tyrosine can preserve mental function when exposed to an acute stressor.

It has also been shown to improve cognitive function, exercise capacity, and appetite in Anorexic mice, possibly just due to correcting Tyrosine deficiency, on of many nutrient deficiencies that are typical among Anorexics.

As with any supplement that corrects a deficiency, the more deficient you are, the more you stand to benefit from L-Tyrosine supplementation.

L-Tyrosine And Exercise

L-Tyrosine is a fairly common ingredient in pre-workout supplements these days, with many supplement companies claiming that it “enhances performance”.

However, studies have shown that it does not impact physical performance.

Some studies have found that L-Tyrosine supplementation helps preserve cognitive function during exercise, but it has failed to do so in other studies.

So, the exercise-related benefits of Tyrosine are unreliable at best.

It may be that L-Tyrosine is only useful during long-duration, high-intensity exercise when Catecholamines would typically become depleted over time.

For the average gym-goer who works out for an hour or two, though, the impact won’t be particularly noticeable.

Is L-Tyrosine Really A “Stress” Supplement?

When we think of stress supplements, herbal adapotgens like Ashwagandha or drugs like Alprazolam (Xanax) and Etizolam tend to dominate the conversion.

Tyrosine doesn’t really reduce stress, though. Its just makes you more capable of dealing with stress.

All of the studies on Tyrosine and “stress” have really tested the impact of Tyrosine on a sudden stressor, like cold exposure.

They measured things like cognitive performance and mood and found that Tyrosine positively impacted these parameters in stressful situations.

To understand what’s happening here, we have to recall from above that Tyrosine serves as a building-block for Catecholamines which control things like mood, energy, cognitive function, and much, much more.

When we’re put in situations that place stress on us, whether physical or mental, we begin to secrete Catecholamines, like Dopamine and Noradrenaline.

If the stressor is severe enough or long-lasting enough, Catecholamines get depleted.  L-Tyrosine helps preserve them.

In other words, L-Tyrosine doesn’t prevent or even curb stress.  It only helps maintain normal cognitive function and mood states during stressful situations.

There’s a big difference between reducing stress and improving your ability to deal with stress.  Tyrosine does the latter.

Why Is L-Tyrosine Included In Pre-Workouts And Fat-Burners?

Originally, Tyrosine was used in pre-workout supplements, fat-burners, and anything that’s supposed to provide an energy boost because of it’s well-established role in Catecholamine production.

Anything that increases Catecholamine release (like Caffeine) will make you feel more energized.

Think of this as the fight or flight response without any danger.

Unfortunately, research shows that L-Tyrosine supplements don’t increase Catecholamine levels.

It can only stick around until the brain runs low.  When levels of Dopamine and Noradrenaline are depleted, Tyrosine serves as a means of restoring them.

Given that many pre-workout supplements and fat-burners contain stimulants (like Caffeine and Higenamine) which trigger the release of Catecholamines and give you energy, it makes sense to include L-Tyrosine.

L-Tyrosine supplementation could potentially help reduce the impact of the dreaded stimulant-crash, which partially happens because of Catecholamine depletion.

Think of it as an insurance policy against running out of Catecholamines.

There are no studies on whether Tyrosine an enhance the cognitive effects of stimulants like Caffeine, but it definitely plays a supportive role.

L-Tyrosine Dosing

It’s usually recommended to take 500-2000mg of L-Tyrosine per day, preferably prior to whatever stressful activity it is that you’re doing.

When it comes to reducing the impact of stressful situations, the clinical dose for L-Tyrosine is at least 2 g, but higher doses may be better.

How much Tyrosine you should take depends on 2 things:

  1. What you’re using it for
  2. How much you get from your diet


By supplementing with L-Tyrosine, you’re just providing your brain and body with the building blocks it needs to produce some of the most essential chemicals/hormones.

If you eat a high protein diet,meaning you get plenty of dietary Tyrosine and Phenylalanine, you may not benefit much from Tyrosine.

N-Acetyl-L-Tyrosine (NALT) VS. L-Tyrosine

Technically, Tyrosine can be found in several different forms, but the most commonly used for the purposes of supplementation are:

  1. L-Tyrosine
  2. N-Acetyl-L-Tyrosine

Now, when you see N-Acetyl-L-Tyrosine (NALT), you usually hear the supplement company claiming it’s “superior in terms of absorption” because “adding an Acetyl group makes things more bioavailable”.

In reality, there is basically no evidence to support these claims about NALT being more bioavailable or better in any way.  So far, it’s just been used as a way of justifying under-dosed Tyrosine supplements.

That’s why it’s a much better idea to just go with L-Tyrosine.  It’s cheap and effective.  Just make sure you’re using a clinical dose and don’t fall for false claims about NALT requiring a lower dose for the same effect.

The Bottom Line On L-Tyrosine

Tyrosine has become extremely popular as a supplement, mostly for the purposes of reducing stress and improving cognitive function.

While the research clearly indicates that L-Tyrosine supplementation can reduce the impact of stress and improve performance in stressful situations, calling it a “stress supplement” is a bit of a stretch.

It’s more like “helps you deal with your stress supplement“.

Have Anything To Add About L-Tyrosine?  Let me know in the comments below…

I’m Matt Theis, founder of SuppWithThat, Momentum Nutrition, and Singular Sport. I created SWT to separate the science from the hype and publish accurate, research-based information on supplements. If you like what I have to say here, feel free to check out my supplements at and

Click to comment
To Top