Tyrosine is an essential building block for major neurotransmitters and can help reduce dopamine-related depression, ADHD, and extreme stress.
Tyrosine, also known as l-tyrosine, is a naturally occurring compound of primary importance for mental health.
It’s a precursor to some of the most important brain chemicals and hormones.
It excels at increasing resilience to extreme stress.
In this article, we look at the benefits of tyrosine, how to get more tyrosine from your diet, and what you need to know about tyrosine supplementation.
What Is Tyrosine?
Tyrosine is an amino acid incorporated in the structure of almost every protein in the body.
Tyrosine gets its name from the Greek word tyros for cheese, since it was first discovered in cheese protein.
Most amino acids are categorized as essential (we need to get it from food) or non-essential (our bodies make its own).
Tyrosine is one of the handful of conditional amino acids.
This means that the body can usually make what it needs, but not always in adequate amounts.
Stress, overwork, lack of sleep, illness, or eating too little protein can all increase the need for tyrosine.
“ There’s been a surprising amount of research done on the effects of tyrosine as a buffer against the harmful effects of extreme stress. Most of these studies were performed by the US and other militaries to help personnel maintain a high level of performance under a variety of severely stressful circumstances.
The two primary sources of tyrosine are certain foods and phenylalanine, one of the 9 essential amino acids.
Tyrosine is required for the synthesis of three important neurotransmitters — dopamine, epinephrine, and norepinephrine.
Neurotransmitters are chemicals that brain cells use to communicate with each other.
They have profound effects on every aspect of life.
Tyrosine is also the precursor to thyroid hormones triiodothyronine (T3) and thyroxine (T4).
It’s also the fundamental component of melanin, the pigment that colors our hair, eyes, and skin.
An Overview of Tyrosine Benefits and Uses
People take tyrosine supplements for a wide variety of brain-related and mental health conditions, such as:
- Alzheimer’s disease
- attention disorders
- Parkinson’s disease
- substance abuse (for withdrawal symptoms)
It is also used to treat chronic fatigue syndrome, heart disease, premenstrual syndrome, and sexual dysfunction.
Reported subjective benefits of tyrosine include:
- anxiety and appetite suppression
- memory enhancement
Tyrosine improves working memory but only in situations where performance is compromised by stress, such as with multitasking.
There’s evidence it can be neuroprotective and may halt cognitive decline in some forms of dementia.
Low levels of tyrosine have been linked to autism.
Now let’s take an in-depth look at the five most important benefits and proven uses for tyrosine.
1. Tyrosine Is the Precursor to Key Neurotransmitters
Tyrosine is an essential building block for a group of neurotransmitters known as catecholamines.
The three main catecholamines are dopamine, norepinephrine, and epinephrine.
By providing the raw material needed for their synthesis, tyrosine helps maintain healthy brain chemistry.
Research confirms that tyrosine is actively transported across the blood-brain barrier to increase levels of dopamine, norepinephrine, and epinephrine in the brain.
Tyrosine is first converted into l-dopa and then into dopamine and norepinephrine.
Here’s a diagram of this chain of events from start to finish.
The amount of tyrosine available to the brain affects the synthesis of the catecholamine brain chemicals.
However, simply increasing the amount of tyrosine in the body does not automatically increase neurotransmitter production.
Neurotransmitter synthesis is regulated by complicated biochemical feedback loops that keep neurotransmitter levels balanced.
However, it seems that ingesting more tyrosine does provide a safety net that helps to prevent neurotransmitter depletion.
Here’s why these neurotransmitters are so important and why you don’t want to have suboptimal levels.
Dopamine plays a role in mood, sleep, learning, memory, focus, and motor control.
It’s called the “motivation molecule” since it provides the drive we need to be productive.
Dopamine is in charge of the brain’s pleasure-reward system.
Dopamine dysfunction is linked to depression, attention deficit hyperactivity disorder (ADHD), schizophrenia, bipolar disorder, substance abuse, and degenerative brain diseases.
Norepinephrine is a dual-purpose chemical that acts as both a neurotransmitter and a stress hormone.
Norepinephrine, along with epinephrine (aka adrenaline), triggers the fight-or-flight response to perceived danger.
It increases heart rate, blood pressure, breathing rate, muscle strength, and mental alertness to prepare the body for extreme stress.
Too little norepinephrine has been linked to depression and ADHD; too much contributes to anxiety.
2. Tyrosine Helps Dopamine-Related Depression
The prevailing theory is that depression is caused by insufficient serotonin.
But the medical community is starting to see that depression may have other underlying causes, such as brain inflammation, low dopamine, and/or low norepinephrine.
Most prescription antidepressants are selective serotonin reuptake inhibitors (SSRIs) which work by increasing serotonin levels.
But other antidepressants act on dopamine, norepinephrine, or a combination of neurotransmitters.
Cymbalta (duloxetine) works by increasing both norepinephrine and serotonin.
Tyrosine works as a natural antidepressant if your depression is due to low levels of dopamine or norepinephrine, rather than serotonin.
But how can you tell?
For now, there are no reliable lab tests that can pinpoint which neurotransmitter imbalance is the cause of your depression.
However, using symptoms to assess your situation works surprisingly well.
Depression due to a low serotonin level is usually accompanied by anxiety.
On the other hand, depression caused by low levels of dopamine or norepinephrine manifests as feelings of apathy, lethargy, and lack of motivation.
You’ll know soon enough if tyrosine is the answer for you because it works surprisingly fast.
One study on patients with dopamine-related depression found that they experienced improvements in mood within one day of taking supplemental tyrosine.
3. Tyrosine Counteracts the Effects of Extreme Stress
There is little evidence that tyrosine will help mental or physical performance under normal circumstances.
But if you are facing acute physical or mental stress, it can be a potent anti-stress supplement.
There’s been a surprising amount of research done on the effects of tyrosine as a buffer against the harmful effects of extreme stress.
Most of these studies were performed by the US and other militaries to help personnel maintain a high level of performance under a variety of severely stressful circumstances.
So far it’s been determined that tyrosine can prevent performance impairment, fatigue, adverse moods, and cognitive decline that occurs in response to physical stressors such as extreme cold, oxygen deprivation, high altitude, sleep deprivation, and the low gravity experienced in space.
During a demanding military combat training course, tyrosine reduced stress and fatigue, lowered blood pressure, and improved cognitive task performance.
Tyrosine was also put to the test in Antarctica, the harshest environment on the planet.
Not surprisingly, the mood among people who stay there during the winter plummets.
But when year-long residents were given tyrosine, they experienced a significant 47% improvement in mood.
However, tyrosine did not help mood during the Antarctic summer; apparently that season was not sufficiently stressful.
In a sleep deprivation study, participants were kept awake for 24 hours straight.
Those given tyrosine did not show the typical decline in mental performance, motor skills, or mood.
Tyrosine is often taken by athletes, but a review of 15 studies found no significant effects of tyrosine on exercise performance.
It’s thought that tyrosine improves physical performance only when the exercise produces enough stress to deplete dopamine or norepinephrine levels.
4. Tyrosine Is an Adjunct Treatment for ADHD
It is widely accepted that the root cause of ADHD is dopamine dysfunction.
Most prescription ADHD medications are based on the “dopamine deficiency” theory.
They work by stimulating the release of the neurotransmitters dopamine and norepinephrine.
Treating ADHD with tyrosine, the precursor to dopamine, shows promise.
So far, the evidence points to tyrosine being a useful adjunct to other ADHD treatments.
In one study, children were given tyrosine along with 5-HTP, a supplement that is a precursor of serotonin.
An impressive 67% of them experienced significant improvement in ADHD symptoms from this amino acid combination.
Another study found that taking tyrosine plus the medication Ritalin worked better at increasing dopamine than Ritalin alone.
A study in adults with ADHD found that tyrosine initially helped with symptoms, but most study participants developed a tolerance and tyrosine supplementation alone no longer helped after six weeks.
5. Tyrosine Is Essential in Treating PKU
Tyrosine is essential for treating phenylketonuria (PKU), a rare inherited amino acid disorder.
People with PKU lack an enzyme that breaks down the amino acid phenylalanine, resulting in its toxic buildup.
If left untreated, PKU can cause brain damage.
There is no cure for PKU, but it is largely controlled by severely restricting phenylalanine in the diet.
Since tyrosine is found in protein-rich foods and synthesized from phenylalanine, tyrosine deficiency often results.
For this reason, tyrosine supplementation is sometimes prescribed.
However, if you have PKU, do not self-administer.
Discuss exactly how much tyrosine you should be taking with your doctor.
The Top Tyrosine Food Sources
Tyrosine is found mainly in protein-rich foods.
Virtually all animal products — meat, fish, poultry, eggs, and dairy — are good sources of tyrosine.
Top plant sources include soy products, squash seeds, pumpkin seeds, sesame seeds, peanuts, wild rice, and oatmeal.
The Best Form of Tyrosine Supplements
Unlike many other natural supplements, tyrosine works very quickly.
There are two main forms of tyrosine supplements available — l-tyrosine and n-acetyl l-tyrosine (NALT).
The NALT form is particularly popular as both a nootropic and as a performance enhancer for athletes and bodybuilders.
There are a lot of claims that NALT is the superior form since it’s highly soluble in water.
But this solubility does not translate into bioavailability.
Research shows that when compared to three other forms of tyrosine, NALT is the least effective at raising blood levels of tyrosine.
This makes sense since the body must break down NALT into l-tyrosine before it can be used, and this is an inefficient process.
One study found that 56% of ingested NALT gets excreted rather than being broken down into l-tyrosine.
Since half of the NALT you take goes down the toilet, it makes sense to use the l-tyrosine form.
There is no Recommended Dietary Allowance (RDA) for tyrosine, but tyrosine supplements typically come in 500 mg doses.
Tyrosine is best taken on an empty stomach 30 minutes before meals and divided into 3 daily doses.
Taking tyrosine on an empty stomach ensures that some is available to create neurotransmitters.
Taking it along with the necessary cofactors vitamin B6, vitamin B9 (folate), and copper helps to optimize tyrosine’s conversion into neurotransmitters as well.
Tyrosine Safety: Side Effects and Interactions
While tyrosine is generally safe, reported side effects include nausea, headache, fatigue, heartburn, and joint pain.
It can worsen some symptoms of schizophrenia.
There’s currently not enough information to determine whether tyrosine is safe for children, pregnant women, or breastfeeding mothers; so in these cases, it’s best to avoid it.
You should not take tyrosine if you have hyperthyroidism or Graves’ disease.
When taken with thyroid medications, supplemental tyrosine can cause thyroid hormone levels to get too high.
It is critical that you not take tyrosine if you are taking a monoamine oxidase inhibitor (MAOI), a medication sometimes prescribed for depression, anxiety disorders, and Parkinson’s.
Taken together, they can cause a severe increase in blood pressure that can lead to a heart attack or stroke.
Tyrosine should not be taken with levodopa, a medication used to treat Parkinson’s disease, since it might decrease this drug’s effectiveness.
Finally, since it is a precursor to dopamine and norepinephrine, tyrosine may interact with or enhance the effects of drugs that affect their production.
Recommended: Upgrading brain health is key to making your brain work better.
Brain supplement can help you:
- Improve your mental clarity and focus.
- Boost your memory and your ability to learn.
- Increase your capacity to think critically, solve problems, and make decisions.
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