By Jillian Levy, CHHC

June 26, 2019

Original article and page source found here.

Tyrosine is an important precursor to neurotransmitters and substances like epinephrine, norepinephrine and dopamine, which means it helps the body produce chemicals that support your thyroid, energy and mood. This is why some people claim that taking this amino acid can help “speed up your metabolism.”

Not only can you get it from eating foods with protein, like meat, eggs or fish, but it is also available in supplement form, which some people take when they are trying to lose weight.

Levels of the amino acids tryptophan and tyrosine fluctuate depending on whether someone eats carbohydrate or protein-rich meals. That means for most people it’s a good idea to include both types of these macronutrients their diets. While eating complex carbs can increase feelings of calmness and even sleepiness, thanks in part to tryptophan boosting serotonin levels, eating protein tends to increase alertness and ability to concentrate, due to a rise in tyrosine.

What Is Tyrosine? (What Does It Do?)

Tyrosine, or L-tyrosine, is one of 20 amino acids that help build proteins. It is considered a “non-essential amino acid” because the body makes it from another amino acid called phenylalanine. This means you don’t need to get tyrosine from foods, although obtaining more from your diet can be helpful.

What are the benefits of taking L-Tyrosine?

As explained more below, L-tyrosine benefits can include fighting fatigue, depression, poor cognitive function and potentially weight gain.

Does tyrosine increase dopamine?

Yes — both dopamine and norepinephrine (also called noradrenaline) production are impacted by the amount of tyrosine you eat or obtain from supplements. Dopamine and norepinephrine are manufactured from tyrosine with the help of several other nutrients, such as folate, B vitamins, copper and magnesium.

Health Benefits

1. Protects Against Stress and May Help Manage Symptoms of Depression

What does L-tyrosine do for the brain?

It helps the brain produce certain stimulating and “feel good” neurotransmitters. Production of neurotransmitters is influenced by your diet, especially the amount and types of amino acids you consume. Tyrosine influences levels of dopamine, which regulates your reward and pleasure centers, and adrenaline, which is responsible for your “fight-or-flight response” when you’re under stress. Stressful situations increase the release of catecholamines, which can result in the depletion of their levels. According to studies investigating L-tyrosine’s effects on stress, the amino acid can help bring levels back up, offering protection against cognitive decline and mood-related changes due to stress (mostly physical stress).

Consuming more of this amino acid may be helpful for people under a lot of stress or who suffer from depression because when levels of dopamine and norepinephrine drop, symptoms like irritability, fatigue and moodiness tend to increase. A 2016 article published in Annals of Neuroscience states:

Depression has been linked to disruption in the cerebral levels of specific neurotransmitters. L-tyrosine is a precursor of more than one of the neurotransmitters affected by depression … many studies have suggested using L-tyrosine as an antidepressant.

There’s some evidence that having higher levels of tyrosine can help improve your mood and increase alertness, the ability to cope with stress and general cognitive functioning. According to some studies, such as one published in the Journal of Psychiatric Research in 2015, it also may be useful during times of physical stressors, including those of interest to the military, such as when soldiers are exposed to cold stress, high-altitude stress or extended wakefulness.

That said, some experts believe that tyrosine’s effects are not strong enough to have a real stress-reducing effect in most people eating a balanced diet. And not every study has found that this amino acid has any substantial antidepressant effects.

2. Can Help Increase Energy and Mental Performance

Does tyrosine make you sleepy?

Not usually. In fact, it tends to do the opposite. While tryptophan is known for increasing drowsiness, tyrosine is thought to boost focus and performance.

How does tyrosine give you energy?

Research suggests that during stressful situations it may help decrease mental fatigue and help with cognitive functions, including memory. L-tyrosine is said to have stimulating effects, which is why it can potentially be used to improve learning and alertness while decreasing brain fog.

One noteworthy effect of taking this amino acid is improving alertness during times of sleep deprivation. One study found that tyrosine helped improve alertness for about three hours among people who were sleep-deprived due to working overnight. Participants in the study remained awake throughout the day on which the experiment began and were awake for more than 24 hours by the end of testing. Six hours after the experiment began, half of the subjects received 150 milligrams per kilogram of body weight of tyrosine (in a split dose) while the other half received a placebo. Those given tyrosine experienced a significant reduction in mental performance decline on the psychomotor tasks lasting about three hours compared to the control group.

3. May Support Weight Loss

Is L-tyrosine good for weight loss?

According to University of Michigan Medicine, “There are no studies specifically showing that L-tyrosine helps to promote weight loss.” However, when used in combination with other natural fat-burning substances, such as cayenne, green tea and caffeine, there’s some evidence that it may help with fat loss in overweight adults, although only slightly. A 2007 study found a very modest reduction in weight of about 0.9 kg when tyrosine was taken by overweight adults along with capsaicin, catechines and caffeine.

Can tyrosine cause weight gain?

It shouldn’t, even if it doesn’t necessarily lead to weight loss or influence your appetite. However, there is evidence that among people needing to gain weight, such as those recovering from anorexia, it may help improve appetite, cognition and exercise tolerance.

4. Supports Thyroid Health and Your Metabolism

What does L-tyrosine do for the thyroid?

It’s used to make thyroxine, a type of thyroid hormone. Thyroxine is the main hormone secreted into the bloodstream by the thyroid gland and helps regulate your metabolism and control levels of T3 and T4 thyroid hormones. It’s important to produce enough thyroxine because this helps decrease symptoms of an underactive thyroid (hypothyroidism), which can include a sluggish metabolism, tiredness, being sensitive to cold, weight gain, constipation, moodiness and weakness.

On the other hand, people who have thyroid conditions characterized by an overactive thyroid, including hyperthyroidism and Graves’ disease, shouldn’t take tyrosine because this might increase thyroxine levels too much, which can interfere with the role of medications and make symptoms worse.

5. May Help Decrease Symptoms of Withdrawal

Studies have found that “dopamine ups and downs” can leave people more vulnerable to addictions. The Integrative Psychiatry website states:

Dopamine, epinephrine, and norepinephrine, (catecholamines), are responsible for motivation, energy, interest, sexual functioning, pleasure/reward, drive, attention, and concentration. They are associated with positive stress states such as being in love, exercising, listening to music, and sex. Deficient levels contribute to difficulty initiating or completing tasks, depression, poor concentration, low energy, and lack of motivation. Addictive behaviors such as alcohol, drug use, cigarettes, gambling, and overeating may also occur.

Ongoing research suggests that tyrosine may be useful for managing symptoms of heroin withdrawal and alcohol withdrawal, along with decreasing alcohol consumption when used along with the drug naltrexone. Taking a combination of tyrosine, 5-hydroxytryptophan (HTP), phosphatidylcholine and L-glutamine seems to have the most effects on improving moods and the ability to sleep in adults addicted to heroin and alcohol, likely because it helps balance levels of catecholamines.

Related: Citrulline: The Amino Acid that Benefits Blood Blow & Performance (+ Foods & Dosage Info)

Top Tyrosine Foods

L-tyrosine is found in foods that provide protein, such as meat and eggs, plus some plant foods in smaller amounts too. Some of the top tyrosine foods include:

• Organic dairy products, like raw milk, yogurt or kefir
• Grass-fed meats and pasture raised poultry
• Wild-caught fish
• Pastured eggs
• Nuts and seeds
• Beans and legumes
• Whole grains like quinoa, oats, etc.
• Protein powders

In order for tyrosine to be converted into neurotransmitters, you also need to consume adequate amounts of certain other nutrients, including vitamin B6, folate and copper. This means that you should also include foods that are high in these nutrients in your diet regularly, such as eggs, grass-fed beef, leafy greens, asparagus, oranges, beans/legumes, almonds and other nuts, seeds like sunflower and chia seeds, whole grains like quinoa and wheat germ, avocado, and broccoli.

Unlike with the amino acid tryptophan, which can have similar mood-boosting effects as tyrosine, levels of tyrosine increase when someone eats foods high in protein or takes supplements. Tryptophan and tyrosine actually compete with one another in the body, which means that when the level of one increases, the level of the other usually decreases.

Supplement and Dosage Info

Tyrosine is available in protein powder form, capsule form and found in some workout supplements. What are some reasons that someone would take a daily tyrosine supplement? Some of the most common reasons are to manage moodiness and symptoms of depression — and also to increase energy and support weight loss.

Another use for tyrosine supplements is treating an inherited disorder called phenylketonuria (PKU), in which the amino acid phenylalanine cannot properly be converted to tyrosine, resulting in low levels. It’s best for people with PKU to consume tyrosine from foods and supplements, but very little phenylalanine from either, since it won’t be able to be processed. For treating the condition PKU, four to six grams of tyrosine daily is usually recommended. Pregnant women with PKU need to consume even more, up to 7.6 grams daily.

How much tyrosine should you take?

In most studies, adults have safely taken about 100 to 150 milligrams per 2.2 pounds (or 1 kg) of body weight, which is equivalent to about 7 grams per day for an average-sized adult. In some situations higher doses are recommended, such as 300 milligrams per kg of body weight taken before a stressful event in order to help with “mental performance,” meaning focus and information retention.

Splitting doses can also be useful if you’re looking to elongate alertness and prevent fatigue. You may need more or less depending on your health status, so start with a low dose and work your way up as needed.

How much L-tyrosine should you take for depression?

A standard dosage range of 9–13.5 grams for a 200-pound person and 7–10 grams for a 150-pound person is recommended.

When should you take tyrosine?

It should be taken on an empty stomach without food, since eating other amino acids can interfere with its absorption. Because it can be stimulating and potentially reduce sleepiness, it’s best when taken in the morning, not in the evening close to bedtime (especially in large amounts).

How long does it take tyrosine to work?

Effects of tyrosine supplements may be felt in as little as 30 to 60 minutes, depending on the dose you take and whether you’ve eaten recently. Taking this amino acid on an empty stomach has faster-acting effects.

Risks and Side Effects

What are the side effects of tyrosine?

Few side effects have been reported, so in supplement form it is considered to be very safe. However, taking large amounts for an extended period of time may interfere with absorption of other amino acids, so it’s best to only use as much as you need.

It’s possible that some people will experience side effects from taking tyrosine, which can include digestive issues like nausea, headache, fatigue and heartburn. That said, high doses up to 20 grams per day have been used in military studies safely.

As mentioned above, people with hyperthyroidism and Graves’ disease shouldn’t take tyrosine due to interactions with thyroid hormones and medications. Anyone taking Levodopa (L-dopa), a medication commonly used to treat Parkinson’s disease, should also avoid taking this supplement.

Here are other common questions about the safety of using tyrosine:

Is tyrosine safe for long-term use?

There isn’t much research showing the long-term effects of taking L-tyrosine, especially in large amounts. It’s best to take less than 1,000 milligrams per day if taking it for many weeks or months. Unless you’re working with a doctor, stick to taking this supplement for about three months or less, in order to reduce the risk for side effects tied to imbalance of amino acids.

Is L-tyrosine a stimulant?

While it can increase alertness and help reduce sleepiness, it’s not a stimulant drug and tends to have milder effects than substances like caffeine.

Does tyrosine cause anxiety?

It shouldn’t. In fact, it may have the opposite effect, unless it increases hyperthyroidism.

Does tyrosine raise blood sugar?

There’s some evidence that it may. Some research conducted at the University of Texas Health Science Center found that tyrosine is elevated in the blood of people who are obese and at high risk of type 2 diabetes or individuals diagnosed with this form of diabetes. This amino acid seems to impact insulin signaling, although more research is needed to determine how this impacts blood sugar management.

Final Thoughts

• Tyrosine is a “non-essential amino acid” that the body makes from another amino acid called phenylalanine.
• What are the benefits of taking L-Tyrosine? These include fighting fatigue, depression, moodiness, trouble concentrating and potentially weight gain.
• Tyrosine foods include those high in protein, such as meat, dairy, eggs, poultry, nuts, seeds and legumes.
• In supplement form, it is typically taken in doses of about 100 to 300 milligrams per kilogram of body weight. Very few side effects have been reported, even when it’s used in high doses. However, taking large doses for an extended period of time