L-Tyrosine: Benefits, Side Effects, Uses and Doses

L-Tyrosine Benefits, Side Effects, Uses and Doses

How can amino acids not be healthy for you? They are supposed to be the building blocks of life. Can there really be any side effects to amino acids? L-Tyrosine or 4-hydroxyphenylalanine is one of the twenty standard amino acids that cells use to synthesize proteins. It is a non-essential amino acid with a polar side group. Its codons are UAC and UAU. Tyrosine comes from the greek word tyros meaning cheese. It is not clear how cheese plays into the function of an amino acid. This particular amino acid was discovered by Justus von Liebig, a German chemist, in the protein casein in cheese. This is how the greek word for cheese ties in. Tyrosine is a hydrophilic amino acid and is much more soluble in water than its precursor, phenylalanine, due to the thermodynamic favorability of the hydrogen bonding between the hydroxyl group of one molecule of tyrosine and the carboxyl group of another.

The many names of Tyrosine:

Insufficient Evidence for the Following Uses

2-Acetylamino-3-(4-Hydroxyphenyl)-Propanoic Acid, Acetyl-L-Tyrosine, Acétyl-L-Tyrosine, L-Tyrosine, N-Acetyl L-Tyrosine, N-Acetyl-L-Tyrosine, N-Acétyl L-Tyrosine, N-Acetyl-Tyrosine, N-Acétyl-Tyrosine, Tyrosine, Tyr, Tyrosinum, 2-amino-3-(4-hydroxyphenyl)propionic acid.           


Tyrosine Origins

Tyrosine can also be found in dairy products, meats, fish, eggs, nuts, beans, oats, and wheat. Tyrosine is produced from another amino acid. Tyrosine is used in protein supplements to treat an inherited disorder called phenylketonuria (PKU). People who have this disorder cannot produce phenylalanine properly so their bodies cannot produce tyrosine. So, to meet their needs they take extra tyrosine supplements. People take tyrosine supplements for the following issues depression, attention deficit disorder (ADD), attention deficit-hyperactivity disorder (ADHD), the inability to stay awake (narcolepsy), and improving alertness following sleep deprivation. It is also used for stress, premenstrual syndrome (PMS), Parkinson’s disease, Alzheimer’s disease, chronic fatigue syndrome (CFS), alcohol and cocaine withdrawal, heart disease and stroke, ED (erectile dysfunction), loss of interest in sex, schizophrenia, and as a suntan agent and appetite suppressant. There are many various reasons why people will take tyrosine. Tyrosine is even applied topically to skin to reduce age-related wrinkles.


How it works

The body uses tyrosine to make chemical messengers that are involved in conditions involving the brain such as mental alertness and many other cognitive functions.


Uses of L-Tyrosine

Uses of L-Tyrosine

Back to the inherited disorder phenylketonuria people who have this have low levels of tyrosine and they are advised to take 6 grams of tyrosine per 100 grams of protein to improve tyrosine levels in the body. Supposedly if you take tyrosine two hours before a test it will help improve memory in healthy people. It will also improve memory, mood and it does not improve mood or speed of reaction to visual or noise stimuli in healthy people.  This is not a proven fact though. Studies have verified that tyrosine does improve memory under stressful conditions as as cold-stress or multitasking.

It will improve mental alertness after loss of sleep. In lines with this Taking 150 mg/kg of tyrosine after someone has lost a night of sleep will help them stay awake three hours longer than they would have otherwise.

Attention Deficit Disorder (ADD) Supposedly taking tyrosine by mouth does not help adults with ADD. Furthermore, Attention deficit-hyperactivity disorder (ADHD). Taking tyrosine by mouth does not seem to help childhood ADHD. Tyrosine taken by mouth is ineffective in treating just mild depression. It don’t even crack major depressive disorders.

Tyrosine fails in exercise performance as well. Taking tyrosine before walking on a treadmill with a load carriage doesn’t help strength or endurance. Also, taking tyrosine, alone or with polydextrose 70, does not seem to improve heart rate or performance during a cycling test. In the above uses tyrosine seems pretty ineffective.


Insufficient Evidence for the Following Uses



Early research may indicate that taking a combination of of D,L-phenylalanine, L-tyrosine, L-glutamine, and L-tryptophan along with a multivitamin might help reduce symptoms of withdrawal and decrease stress in alcoholics. Key word here is might it is not a proven fact that these combinations will bring about the desired results.    


Cocaine dependence

Early studies suggest that taking L-tyrosine in the morning and and L-tryptophan at night doesn’t help people with cocaine cravings or withdrawal symptoms. Another use that this amino acid may fail in.



Leave it to early research. But early research suggests that combination of tyrosine, 5-hydroxytryptophan (5-HTP), and carbidopa by mouth  does not improve symptoms in people with severe dementia due to alzheimer’s disease or multi-infarct dementia. Why it was thought this amino acid could help with these mental disorders is yet to be determined.  


High blood pressure (hypertension)

Early research seems to point to the fact that taking tyrosine by mouth does not affect the symptoms of slightly elevated blood pressure.


Excessive sleepiness or Narcolepsy

Excessive sleepiness or Narcolepsy

Studies suggest that taking tyrosine by mouth may help to reduce some symptoms of narcolepsy, such as feelings of tiredness, based on patient ratings. This is a subjective standard and is not an accurate measurement. Based on objective evidence tyrosine seems to not help to reduce most of the symptoms of narcolepsy.   



It does not make sense as why an amino acid  would be considered a viable option to treating schizophrenia. Anyway, early research suggests taking  L-tyrosine along with the drug molindone for 3 weeks does not improve symptoms of schizophrenia better than molindone alone. This suggests that adding L-tyrosine to molindone was no more effective than molindone used independently.  


Weight Loss

Taking a combination of tyrosine, cayenne, green tea, caffeine, and calcium for 8 weeks seems to slightly reduce body fat mass by 0.9 kg in overweight people. This is not a significant amount and here tyrosine does not shine in helping with weight loss. However, the combination supplement does not seem to improve blood pressure, heart rate, or the excretion of fat in the feces.  


Wrinkled Skin

A topical preparation containing 10% vitamin C as L-ascorbic acid, acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum)  applied for three months topically to facial skin aged by sunlight may reduce fine and coarse wrinkling, yellowing, roughness, and skin tone.


Other uses Needing Evidence:

  • Stress.
  • Premenstrual syndrome (PMS).
  • Parkinson’s disease.
  • Chronic fatigue syndrome (CFS).
  • Alzheimer’s disease.
  • Heart disease.
  • Erectile dysfunction (ED).
  • Other conditions.

More evidence is needed to rate the effectiveness of tyrosine for these uses.


Side Effects:

Tyrosine may be safe taken orally in food  amounts and maybe safe when taken by adults in medicinal amounts or when applied to the skin. Tyrosine seems to be safe when used in doses up to 150 mg/kg per day for up to 3 months. Some side effects recorded are nausea, headache, fatigue, heartburn, and joint pain. There is not enough evidence to suggest that it is safe to give tyrosine to children for medicinal purposes. Always consult a doctor before administering tyrosine to children for any reason.  


Pregnancy and Breastfeeding

Pregnancy and Breastfeeding

As mentioned so many times there just is not enough evidence to show whether tyrosine is safe to use while pregnant or breastfeeding. The best bet don’t use it under these two circumstances.


Overactive thyroid (hyperthyroidism) or Graves disease

The body uses tyrosine to manufacture thyroxine, which is a thyroid hormone. Taking excessive tyrosine might increase thyroxine levels too much, making hyperthyroidism and Graves disease worse. If anyone has any one of these conditions don’t take tyrosine supplements.




The following doses have been studied in scientific research:



  • For improving alertness after being without sleep for a long time: 150 mg/kg/day of tyrosine. This will add about 3 hours of mental alertness.
  • For PKU: The current recommendation for people with PKU is the incorporation of 6 grams of tyrosine per 100 grams of protein. However, additional separate supplementation with free tyrosine is not advised because it can produce expansive changes in the amount of tyrosine in the blood and could cause unwanted side effects. Whether any of these side effects are fatal is not known. The side effects were not discussed.
  • 500 – 2000 mg taking L-tyrosine for acute stress 30 – 60 minutes before
  • 9 – 13 g (200 lb) or 7 – 10 g (150 lb) from studies

Usually people take the first dose of L-tyrosine for stress-related problems. Studies have shown what doses humans can actually take but keep in mind there are theoretical uses that can be taken as well. Always take a dose that is in the lower side of potency.


More Negative Side Effects:

Many people who have taken L-tyrosine claim that there are few if any side effects. But few side effects there are. Remember L-tyrosine is an amino acid with weak biochemical changes attached to it. In other words it cannot produce a lot of dramatic changes within the human body. Compared with so drugs carry a potent biochemical change which is attached to them. This means they can make some dramatic changes in the human body. One of the major side effects of L-tyrosine is the headache which seems to be common among users. The headache can be a product of taking L-tyrosine or it could accentuate a pre-existing condition such as migraine headaches.

The most important thing that you can consider when taking L-tyrosine is that it provides more dopamine into the brain. This alteration of brain chemicals can spell serious side effects for someone who is already struggling with migraine headaches. The migraine headache sufferer is usually suffering from an inability to metabolize dopamine properly, which causes a buildup and then pain. Adding extra dopamine to the brain will just fuel the migraine fire. It means that the migraine headache sufferer should not take tyrosine supplements. If they do they will multiply the symptoms of their migraine headaches. No studies have confirmed these side effects for migraine patients but just te same they should stay away from this amino acid.

There seems to be few side effects with L-tyrosine but there are a couple. If you suffer from thyroid problems don’t take this amino acid you could make the problem far worse.


Benefits of L-Tyrosine

One fact about L-tyrosine is that is is the most important of the twenty amino acids because it is a product of neurotransmitters. Some of the benefits are it helps the brain and it is a pigment- parting agent for the skin. It is also an essential building block of some hormones. These hormones were not listed. Tyrosine is supposed to be involved in many vital activities related to the body. Tyrosine can reduce depression, mood disorders, Parkinson’s disease and in some cases Alzheimer’s disease. Tyrosine can also be effective in making strong muscles. According to other sources it cannot help with depression or alzheimer’s disease.

Some studies suggest tyrosine may help to relieve fatigue, stroke, and it also increases the memory of an individual. Again other sources have said that it cannot help with fatigue. It is said to play a vital role in sending signals throughout the body. There is not a lot of research to back up this claim. This is an unknown benefit that it produces neurotransmitters when in fact it is manufactured by neurotransmitters.

Tyrosine fortifies the immune system and also provides nourishment and strength to other organs of the body, because it acts as a cortisol regulator. There is no evidence to show that it is a cortisol regulator or that it helps the immune system in any way.  This amino acid is also the precursor of melanin. This protein component can enhance the function of pituitary and adrenal glands, boosting up the performance of these two glands results in formation of progesterone hormone. There needs to be more research done on the hormonal benefits.

Tyrosine is said to protect the nerves from toxins but there seems to be no medical support for this claim either. It is not known how an amino acid can relate to nerve activity of any kind.


Natural Food Sources for L-tyrosine:

  • Seaweed
  • Egg Whites
  • Cottage Cheese
  • Salmon
  • Turkey
  • Pumpkin Flesh
  • Pork
  • Mustard Greens
  • Chicken
  • Buffalo
  • Cod
  • Tuna
  • Sesame Seeds
  • Kidney Beans
  • Spinach
  • Avocado
  • Banana


Food Recipes  Containing L-Tyrosine:


Seaweed Benefits:

  • Has important antibacterial and antiviral effects.
  • Reduces cholesterol levels in the blood, high blood pressure and arteriosclerosis.
  • Helps discharge other radioactive elements.
  • Macrobiotic doctors & patients in Nagasaki, survived the atomic bombing in August of 1945. They protected themselves against lethal doses of radiation on a diet of brown rice, miso soup, seaweed and sea salt.
  • Contains B12 (rarely found in vegetables).
  • Is rich in iron, potassium, magnesium, zinc, manganese and 60 trace minerals.
  • Provides a substance called aliginic acid that helps the body eliminate toxins. (Study at McGill University in Montreal)
  • When the body is saturated with natural iodine from seaweed, it will more readily excrete radioactive iodine taken in from the air, water or food.
  • Contains 14 times more calcium by weight than milk.
  • Is high in protein, low in fat and contains little or no carbs.
  • Has components that lower blood pressure.


Seaweed Recipes

Food Recipes Containing L-Tyrosine


Green Nori Salad


  • Leafy lettuce
  • Onions
  • Nori seaweed
  • Lemon Juice or Umeboshi Vinegar
  • Sea salt
  • Olive oil


  • Tear lettuce into pieces.
  • Slice onion very thinly and chop finely, mixing together.
  • Lightly toast Nori until it turns a green color and is crumbly.
  • Mix in a few drops of olive oil with the lettuce.
  • Sprinkle lemon juice and salt on lettuce and toss.
  • Crumble Nori into the salad.
  • Toss and serve.


Carrots with Arame


  • ½ cup arame
  • 2 – 3 tbsp. tamari
  • ½ tbsp. fresh ginger, grated
  • 3 – 5 carrots cut into matchstick lengths


  • Cover arame with water.
  • Soak arame for 10 minutes.
  • Boil arame, tamari, and grated ginger uncovered and on low until most of the liquid has evaporated.
  • Add the carrots.
  • Cover and cook until carrots are slightly tender.
  • Remove lid and cook until all the water has evaporated.


White Bean and Asparagus Stew


  • 1 1/2 cups dry white beans
  • 2 pieces of Wakame (seaweed)
  • 4 bay leaves
  • 1 large onion, chopped finely
  • 1/2 lb. green asparagus, remove woody stems, cut into 2-inch pieces
  • 4 Tbsp vegetable oil or unsalted butter
  • 2 carrots, sliced in rounds
  • 2 pieces celery, chopped
  • 1 – 3 cloves of garlic, chopped
  • 1/4 tsp Liquid dark stevia
  • 1 tsp basil
  • 1 tsp marjoram
  • 2 – 3 Tbsp Tamari or 2 – 3 Tbsp Braggs
  • 1 Tbsp minced fresh parsley oil
  • freshly ground black pepper


  • Cook beans for 1 – 2 hours (time depends on the age of the beans)
  • When beans are soft, add Wakame, bay leaves, Braggs, Tamari, basil, marjoram and stevia.
  • Sauté onion, celery and garlic in oil. When golden brown, add to the cooked beans.
  • Add carrots and asparagus.
  • Simmer for half an hour or till vegetables are tender.
  • Mix in parsley and add black pepper to taste.



The many names of Tyrosine

We added a little bit of everything to this article. We talked about what L-Tyrosine is and how it is manufactured by the human body. We also found that ig can be taken by supplements as well. It seems to be a very important amino acid to the body and it plays some critical roles in communicating with different parts of the body. It has some important benefits and few side effects. There is a lot of unknowns about some of its uses because there just is not enough to confirm whether the uses are valid or not.

Leave a Reply

Your email address will not be published. Required fields are marked *