As a precursor for dopamine, adrenaline, and noradrenaline, L-tyrosine is a must in any good pre-workout formula. Studies show that you’ll need about 100-150 mg per kilogram of body weight to maximize focus and mitigate stress.

If you’re in the market for a good pre-workout, chances are you’ve tried a bunch—maybe you’ve found one that works, and perhaps you haven’t.

But in any case, there’s one ingredient you might see (after caffeine): tyrosine. It’s one of the most common ingredients in a pre-workout formula, and frankly, it wouldn’t be a pre-workout without it.

If you’re unsure why we love tyrosine, there’s a simple answer—focus. It can increase your focus and help you maximize your time in the gym.

But what is the amino acid tyrosine, and what’s a good dose to achieve the results you’re looking for? Keep reading, and we’ll cover everything you need to know about L-tyrosine and pre-workout.

What is L-tyrosine?

Pre-workouts are notorious for containing all kinds of ingredients—some effective, some not—but if there’s one that deserves a place on a label, L-tyrosine it is. But what exactly is tyrosine, and why should you take it?

L-tyrosine is a non-essential amino acid and probably one of the most misunderstood compounds in the fitness world.

You’ll commonly see it stacked in a fat-burning formula thanks to its role in supporting thyroid hormone production, but tyrosine has minimal impact on fat burning, and there are few studies to support its role.

So, what does it do if it’s not involved in fat burning?

Focus. Tyrosine helps you focus and takes the edge off during stressful situations.

Tyrosine is a precursor amino acid to some of the most powerful neurotransmitters in the body involved in attention, focus, mood, and motivation.

But it’s also a precursor for essential compounds called catecholamines that stress and intense physical exertion affect.

As such, altering levels of tyrosine in the brain can influence the production of serotonin, dopamine, and catecholamines (epinephrine and norepinephrine) 1.

But why does intense exercise deplete catecholamines, and how does taking the amino acid tyrosine prevent that?

Any form of stress— physical, mental, or emotional—activates your sympathetic nervous system (SNS) and puts your body into fight-or-flight mode.

When the SNS is activated, your body pumps out the stress hormones cortisol, epinephrine, and norepinephrine to prepare your body to fight or flee.

This causes an increase in blood pressure and heart rate and increases glucose circulation in the blood to sustain energy levels. When the stress persists, for example, during a 90-minute workout, levels of the catecholamines start to decline.

And because L-tyrosine serves as a precursor to their production, low tyrosine levels mean the body can’t replenish what it needs to maintain performance.

So, tyrosine supplementation in a pre-workout supplies the building blocks to naturally boost hormone levels and mitigate the risk of potential imbalances 2.

That said, you won’t get the same effect under normal conditions. It appears only to enhance the production and release of catecholamines during acute stress.

Now that you know a bit about why we use tyrosine, let’s look at how it works.

How does L-tyrosine work?

We’re all familiar with the premise behind Lego blocks, the infamous childhood toy that, when put together, can produce almost anything in a child’s wildest dreams.

When you dump a bucket of Lego, you work diligently to build a masterpiece out of hundreds of tiny pieces.

Amino acids are, in many ways, no different than Lego blocks. With the 20 amino acids in the body, you can combine them in hundreds of combinations to build proteins. But without the right building blocks, making anything of substance is virtually impossible.

The building blocks--the neurotransmitter precursor amino acids--we’re talking about can make catecholamines—brain chemicals essential for facilitating functions in the central nervous system that regulate mood, cognition, and memory.

They also facilitate the brain's production of dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).

So, a steady supply of tyrosine is essential to maintain adequate production of the catecholamines and, therefore, to maintain motivation, focus, attention, and a good mood.

Let’s dig into that.

Tyrosine and Dopamine

Ever heard of dopamine before? When you eat something you like or crave, your body releases dopamine. Or, when you do an activity you enjoy, you’ll get a dopamine hit.

Dopamine is the pleasure or “feel good” hormone that keeps you coming back for more; we crave that dopamine hit, so we seek out pleasurable things.

We take tyrosine to produce dopamine because upon ingestion, it crosses the blood-brain barrier and binds to specific brain cells.

An enzyme called tyrosine hydroxylase then comes along and converts tyrosine into a molecule called L-DOPA, which is then converted into the neurotransmitters collectively referred to as the catecholamines—epinephrine (noradrenaline), dopamine, and adrenaline 3.

Research shows that blood levels of tyrosine peak about 1-2 hours after consumption and can stay elevated for up to 8 hours 4. As such, the effects of tyrosine on mental performance are pretty long-lasting.

But dopamine isn’t the only product of taking tyrosine. It’s also used to produce:

  1. Epinephrine (adrenaline):​ Adrenaline plays a crucial role in your body’s stress response; it is one of the fight-or-flight hormones that trigger vasodilation, an increase in blood pressure, heart rate, and respiration rate, and increases glucose supply in the blood to maintain energy levels.

  2. Norepinephrine (noradrenaline):​ Along with adrenaline, norepinephrine facilities the same actions to support the body’s fight-or-flight response during periods of acute stress to increase blood pressure, glucose levels, and respiration and heart rate.

  3. Thyroid hormones: Produced primarily by the thyroid gland, thyroid hormones are an integral part of regulating growth and development, energy metabolism, and regulating your heart, muscle, and digestive function, brain development, and bone health 5. Tyrosine is needed to produce T3 and T4—the major thyroid hormones.

  4. Melanin: This is the pigment that gives your skin, hair, and eyes color. The formation of melanin, known as melanogenesis, is a multi-step process that starts with converting amino acid L-tyrosine to DOPAquinone 6.

Given the various biological functions of tyrosine, it’s no wonder it’s prized. But apart from roles in cognitive function, some research suggests tyrosine administration could also play a role in exercise.

For example, boosting dopamine, adrenaline, and norepinephrine levels could give you an edge in training and improve mental performance.

But what does the research say? Let’s dive into the benefits of L-tyrosine for exercise performance.

L-tyrosine and athletic performance

While tyrosine isn’t likely to elevate your athletic performance by enhancing fat burn like cayenne pepper might or preventing fatigue like beta-alanine, it has a unique way in which it supports training—that’s through cognitive function.

During stressful situations, the body upregulates the release of specific compounds that keep the body running on high; these are the compounds we discussed: adrenaline and noradrenaline.

As a result, your body burns through the brain chemicals needed to sustain optimal performance. With continual stress, levels of the catecholamines start to decline—and we can add caffeine-induced stress into the picture, too.

The result? Diminished athletic performance, poor focus, mood issues, crashes, and fatigue. The perfect combination to tank your workout and results.

But when you supplement with tyrosine in your pre-workout formula, you supply your body with the building blocks needed to rebuild and replenish levels of these chemicals.

Here’s some of the research to back it up.

  • A 2010 study looked at the effects of acute and prolonged (4-weeks) ingestion of a supplement containing tyrosine designed to improve reaction time and subjective measures of alertness, energy, fatigue, and focus compared to placebo 7. Results showed that acute ingestion improves reaction time and subjective feelings of focus and alertness following exhaustive exercise.

  • A 2011 study published in the European Journal of Applied Physiology examined whether supplementing the amino acid precursor to dopamine could improve exercise capacity in the heat 8. Results showed that acute tyrosine supplementation could increase endurance capacity in the heat in moderately trained subjects and can also influence the ability to subjectively tolerate prolonged submaximal constant-load exercise in the heat.

  • A study published in Pharmacology Biochemistry and Behavior has eight males perform a memory-based computer task and found that performance at 4 degrees Celsius (39 Fahrenheit) was more reliable with tyrosine supplementation 9.

  • Another study published in the Brain Research Bulletin found tyrosine supplements can help to stabilize mood and maintain performance during cold exposure and low oxygen levels 10.

While the training situations you’re in aren’t likely to replicate these studies, they show how tyrosine might be helpful for your workouts.

They increase stress, boost body temperature, and jack up catecholamine release, and supplementing with tyrosine could help slow the depletion of these important hormones.

But how much is enough to get the beneficial effects?

How much L-tyrosine to take?

The beneficial dosage depends on what you want from your supplement. Most studies use a dose of around 100-150 mg per kg of body weight, which translates to about 7 grams for the average-sized adult. But for higher stress levels, increasing the dose to 300 mg/kg might offer more benefit.

Here’s a general breakdown of dosage for specific purposes:

  • For alertness: 150 mg per kg of body weight (mg/kg) split into two doses.

  • For memory: 150 mg/kg to 300 mg/kg taken before a memory task.

  • For mental performance: 100 mg/kg to 300 mg/kg taken before a stressful mental task.

Where to find L-tyrosine

Whether you’re looking for dietary tyrosine or supplementation, there are plenty of places to get your hands on it—but combining them might be the way to go!

When it comes to dietary tyrosine sources, here are some of your best options:

  • Organic dairy (raw milk, kefir, yogurt)
  • Grass-fed meats (beef, pork, elk, bison, venison)
  • Pasture-raised poultry
  • Wild-caught fish and seafood
  • Pastured eggs
  • Nuts and seeds
  • Beans and legumes
  • Whole grains (quinoa, oats)
  • Protein powders

    All animal-based proteins will be high in specific amino acids, many of which will contain tyrosine. For people that won't eat meat, there are several plant-sources of the amino acid to boost your intake.

    In terms of a pre-workout, there’s only one thing we’ll recommend: Pre Lab Pro®.

    It’s the cleanest and most-effective pre-workout supplement designed to supercharge your athletic performance using a patented blend of research-backed ingredients.

    How does Pre Lab Pro® work?

    1. Bigger nitric oxide boost: Pre Lab Pro®'s 2X nitric oxide stack boosts and sustains blood flow to muscles, delivering a clean rush that enhances strength, stamina, focus, and endurance.

    2. Smarter stimulation: 80 mg of natural caffeine, L-theanine, L-tyrosine, and nootropics stacked to support more energy, focus, and intensity with fewer jitters, crashes, and side effects.

    3. Stronger homeostasis: Pre Lab Pro® tops you off with crucial nutrients before training to help you perform at your peak, maintain hydration and electrolytes, resist stress, accelerate recovery, and feel great after your session.

    Side effects of tyrosine supplements

    Tyrosine supplements are recognized as safe by the FDA, but they can result in side effects for some people, including headaches, nausea, fatigue, and heartburn.

    However, tyrosine supplementation may not be safe for people taking specific medications:

    1. Monoamine oxidase inhibitors (MAOIs): Medications to treat depression such as rasagiline (Azilect), selegiline (Eldepryl, Zelapar), isocarboxazid (Marplan), phenelzine (Nardil), and tranylcypromine (Parnate).

    2. Levodopa (L-DOPA): Parkinson’s disease medication

    3. Thyroid hormone pills: Synthroid or Levothroid

     Always consult your doctor before starting a new supplement if you are taking medications.

    Final Thoughts

    It’s easy to be sucked into the world of nutrition and fitness supplements, but when you can understand what’s in them and what they do, it’s easy to see through the fog and find exactly what you need.

    L-tyrosine is a solid option if you’re looking for a supplement to enhance focus, motivation, and overall performance.

    And the best part is that it benefits other aspects of well-being, meaning you’re getting a serious bang for your buck.


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    2. SN Young. L-tyrosine to alleviate the effects of stress? J Psychiatry Neurosci. 2007;32(3):224.
    3. Daubner SC, Le T, Wang S. Tyrosine hydroxylase and regulation of dopamine synthesis. Arch Biochem Biophys. 2011;508(1):1-12.
    4. Glaeser BS, Melamed E, Growdon JH, Wurtman RJ. Elevation of plasma tyrosine after a single oral dose of L-tyrosine. Life Sci. 1979;25(3):265-271.
    5. Shahid MA, Ashraf MA, Sharma S. Physiology, Thyroid Hormone. (Updated 2022 May 8). In: StatPearls (Internet). Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
    6. Rzepka Z, Buszman E, Beberok A, Wrześniok D. From tyrosine to melanin: Signaling pathways and factors regulating melanogenesis. Postepy Hig Med Dosw (Online). 2016;70(0):695-708.
    7. Hoffman JR, Ratamess NA, Gonzalez A, et al. The effects of acute and prolonged CRAM supplementation on reaction time and subjective measures of focus and alertness in healthy college students. J Int Soc Sports Nutr. 2010;7:39.
    8. Tumilty L, Davison G, Beckmann M, Thatcher R. Oral tyrosine supplementation improves exercise capacity in the heat. Eur J Appl Physiol. 2011;111(12):2941-2950.
    9. Shurtleff D, Thomas JR, Schrot J, Kowalski K, Harford R. Tyrosine reverses a cold-induced working memory deficit in humans. Pharmacol Biochem Behav. 1994;47(4):935-941.
    10. Banderet LE, Lieberman HR. Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans. Brain Res Bull. 1989;22(4):759-762.