Have you ever felt completely drained, or irritable after a long day at work?  Have you had difficulty staying motivated even when you really needed or wanted to? Stood up to give a presentation and had your mind go blank? 

The truth is, most of us have been in one of the above situations and this very reaction likely has a lot to do with the amino acid L-tyrosine. 

Amino Acids – The Lego blocks of your body

We’re all familiar with the basic premise of lego blocks - you dump them out on the ground and work diligently to build something out of the hundreds of small pieces. Aside from being physical pieces, amino acids are no different in many ways to lego blocks when it comes to our body. Amino acids act as the building blocks of protein in our bodies. Without the blocks, it’s incredibly difficult to build anything of substance. With the right blocks available, your body is able to build everything your body needs.

Tyrosine blocks can build neurotransmitters.

Let's talk about catecholamines. While you may not have heard about this term specifically, you have likely heard of what makes them up. This includes dopamine, epinephrine (adrenaline) and norepinephrine (noradrenalin).

When it comes to the building block required to produce catecholamines, that is Tyrosine. Brain health, which includes our mood, cognition, and memory relies on the balance of these (and other) neurotransmitters.  

A steady supply of L-tyrosine is important for your body to keep producing catecholamines, which means a steady supply of tyrosine is important for motivation, focus, attention, and overall happiness. 

So how do we get from L-tyrosine to neurotransmitters?

As my supervisor  in grad school always said; “let’s dig into the mechanism”.  

So, let’s do just that.

Blood levels of tyrosine peak 1-2 hours after taking it, and can stay elevated for up to 8 hours (1). L-Tyrosine can pass the blood-brain barrier - the wall in the brain that says what can go in and out.   Only certain brain cells will take up tyrosine.  In these cells, an enzyme called “tyrosine hydroxylase” will transform tyrosine into L-DOPA. 

L-DOPA is then finally transformed into the neurotransmitter dopamine. 

Keep in mind; the brain is tightly controlled.  There are different checkpoints to make sure that everything stays in balance.  Taking extra tyrosine will not make more dopamine if your brain doesn’t need it.  This is where the enzyme tyrosine hydroxylase saves the day, by regulating this very process. 

As great as dopamine is, you can have too much of a good thing, which will actually lead to a  decrease in performance.   That is why it is always important to watch out for products that contain L-DOPA or Mucuna pruriens (velvet bean extract that contains L-DOPA).  L-DOPA bypasses tyrosine hydroxylase, and you could end up with too much.


Being cold on a mountain

One of the first scientific papers to study tyrosine and cognition was written almost 30 years ago (2).  This study simulated putting military soldiers on a cold mountain, and asked them to perform math tests.  These soldiers didn’t perform well and also were not very happy.  The theory was that the stress of being in high altitude and in the cold while performing a cognitively demanding task was depleting dopamine.  They had worse mental performance because of this.  When the researchers supplemented another group of these soldiers with Tyrosine to replenish their tyrosine stores, they were able to maintain their mental performance despite the cold and high altitude.  

Since this first study, many others have shown the benefits of taking tyrosine during various stresses such as extreme heat (3), extreme cold (4) and sleep deprivation (5). 


Now that we know how it works… let’s talk about WHY L-tyrosine enhances brain function.

OK, you're not planning on doing calculus in the extreme cold, but tyrosine is still really important, as one thing all these studies have in common is STRESS.

Tyrosine works based on something called the “repletion effect” which is literally the opposite of the depletion effect.  

Let’s simplify. Think of your brain as a car.  Your brain-car needs fuel to run.  When you are driving fast, you burn more fuel, and if you run out, your car will stop running. This is an example of the depletion effect.  When you pull into a gas station and fill up the gas tank that is an example of the “repletion effect”.

During times of cognitive stress like zoom meetings, multitasking, math tests, or something as simple as driving, the neurons that release dopamine become very active.  

At the same time, as a society we are reporting record high levels of emotional and workplace stress (6).  If you are feeling stressed, without even knowing it, you are also activating your fight-or-flight stress response.  

Remember those other two catecholamines we mentioned? Epinephrine and norepinephrine?  

You will remember that they use tyrosine as a building block as well.  When you are feeling stress (fight or flight), your body starts to dump large amounts of epinephrine and norepinephrine into your bloodstream to cause the fight or flight stress response.  

Higher brain functions AND stress response both rely on tyrosine to make catecholamines.  If one (or both!) of these systems is being pushed hard, this can lead to shortages.  Unfortunately, if you are stressed out, it is your brain that gets the short end of the stick.  From an evolutionary perspective, it makes sense.  If you have a lion chasing you, you need to run.  You don’t need to form and present a cohesive argument as to why you would make a terrible meal.

Scientific studies show that if you give back tyrosine (replenish the stores), you can actually maintain mental performance during stress. 

L-Tyrosine vs. Other Forms

Many nootropics out there rave about different forms of tyrosine or even sources of L-DOPA.  

So why did we stick with plain old L-tyrosine? 

Honestly, because it is tried and true.  L-Tyrosine is the form that has been the most clinically studied and proven effective.  Plus, it is the form of tyrosine most commonly found in food.  At MindGain we whole-heartedly believe in the KISS adage, “Keep it super simple”.  The brain is complex enough, the last thing we need is to add unproven forms of nutrients.