Everything You Need To Know About L-Tyrosine
By CANDICE GREY
Updated on Aug 08, 2019
What is L-Tyrosine?
L-Tyrosine (also referred to as simply Tyrosine) is a non-essential amino acid which is needed by the body to synthesize the neurotransmitters dopamine, epinephrine, and norepinephrine. It’s synthesized like this: the enzyme L-Tyrosine hydroxylase converts phenylalanine into L-Tyrosine, then into these neurotransmitters. Due to the effects of these neurotransmitters, L-Tyrosine has the benefits of enhancing one’s mood, improving cognitive function, treating sleep disorders, and treating depression. 
Phenylalanine is obtained from high-protein foods like milk and cheese, bananas, and peanuts, or it may be obtained from dietary supplements. There are two supplemental forms—L-Tyrosine and N-Acetyl-L-Tyrosine—which are recommended at a daily dosage of 500-1000mg and 300mg respectively, to be taken 30 minutes before a meal. These supplements may be in the form of capsules, pills, or a drink powder. Tyrosine by itself is an exceptional supplement; however, its effects may be enhanced by stacking it with other chemicals such as Aniracetam and Citicoline.  back to menu ↑
Facts About L-Tyrosine
- The word Tyrosine comes from the Greek word tyros, meaning “cheese.” This is in reference to the fact that this supplement was first discovered from casein—a protein in the milk of all mammals—in 1846.
- This supplement is thought to be particularly helpful in a number of processes within the body, including influencing the production of a number of neurotransmitters.
- When ingested directly in the form of a powder, pill, or capsule, Tyrosine crosses over the blood-brain barrier and enters the central nervous system fairly quickly.
Foods Containing L-Tyrosine
L-Tyrosine itself may be obtained from a wide variety of foods: milk, cheese, yogurt, chicken, turkey, almonds, avocados, lima beans, pumpkin seeds, sesame seeds, eggs and salmon.
- Nuts and seeds contain a large amount of the phenylalanine needed to make L-Tyrosine; the amount ranges from 1400-3000mg per serving.
- Pork chops, salmon, turkey and chicken are also rich in tyrosine, with 900 to 1,000 milligrams per 3-ounce cooked portion.
- Parmesan cheese contains a whopping 559 mg of tyrosine per ounce.
- Roasted soybeans contain 1,392 mg of tyrosine per cup
- Eggs provide 250 mg of tyrosine each. 
Benefits of L-Tyrosine
There are many benefits associated with the intake of supplemental L-Tyrosine, as well as ensuring adequate amounts are obtained from food sources. Chief among the benefits of L-Tyrosine is treatment of the Phenylketonuria, a hereditary disease. Phenylketonuria is a condition in which the persons affected cannot utilize phenylalanine, the building block of L-Tyrosine. These persons need to satisfy their need by taking a dietary supplement or by including foods rich in L-Tyrosine. When tyrosine levels are low as in this case, taking supplemental tyrosine has proven effective in treating this condition. 
Other benefits include improved cognitive function, improving one’s mood, treatment of depression, and increase in sex drive, as well as some functionality in weight management.
Several studies have confirmed Tyrosine’s effectiveness in combating conditions of stress and depression, and in aiding certain tasks which require increased mental focus and attention. Epinephrine, norepinephrine and dopamine are depleted during times of stress or strenuous mental activity, and when supplemental Tyrosine was administered researchers observed that individuals performed better than those who were not given the supplement. In addition, the individuals given Tyrosine supplements were able to switch between different tasks more efficiently; this is due to the fact that dopamine is responsible for cognitive flexibility as well as functioning to increase libido and enhance mood.  
L-Tyrosine may be used to treat attention deficit-hyperactivity disorder (ADHD) and improve alertness in persons who are sleep-deprived; a dosage of 150mg normally results in increased mental capability for at least 3hrs.
Tyrosine also has the benefit of increasing weight loss, as epinephrine and norepinephrine have the ability to both suppress appetite and reduce the amount of fat stored. Tyrosine may be taken with other substances—such as cayenne, caffeine, or calcium—to enhance the overall result. 
Recent studies have found that L-Tyrosine may aid in the treatment of anxiety disorder. When an individual has an anxiety attack there is an excess of glutamate in the blood, which causes over-excitement of the nerves, resulting in a host of problems as well as nerve damage. Tyrosine’s participation in the synthesis of dopamine has a direct effect on the amount of glutamate that is allowed to affect the nervous system. A tyrosine dosage of 200-500mg taken one to three times per day before eating is used to treat this disorder. It should be noted that tyrosine supplements are not be taken at night, to avoid altering sleeping patterns. The most common side effects associated with tyrosine treatment for anxiety are headache, periodic bouts of nausea, diarrhea, and vomiting, which is usually as a result of higher-than-prescribed doses. 
Tyrosine is also used for the production of melanin, the chemical responsible for giving the skin, eyes, and hair their color. The enzyme tyrosinase oxidizes tyrosine into melanin, in specialized cells known as melanocytes. Melanin seems to have a protective effect of absorbing sunlight and dissipating it, thereby reducing the risk of skin cancer. On the other hand, an absence of melanin in the body is a hereditary condition known as Albinism; there is no pigment in the skin, eyes, or hair, as the gene for encoding tyrosinase is absent. The melanocytes are unable to oxidize tyrosine and individuals suffering from this condition may be at a higher risk of developing skin cancer. back to menu ↑
Is L-Tyrosine Ever Bad for You?
L-Tyrosine is considered safe and well-tolerated for healthy individuals, with relatively mild side effects from supplement forms such as nausea, migraine and gastrointestinal discomfort. Food sources do not seem to share these effects. The recommended dosage is 150mg per day for a period of 3 months; as treatment of phenylketonuria a dosage of 6g of tyrosine per 100g of protein. Care should be taken to exclude other sources that may supply more tyrosine to the diet.
Other side effects of Tyrosine are anxiety and nervousness due to its stimulant properties. Additionally, tyrosine may cause gastric upset, as it allows the esophagus to relax—which enables fluid to leave the stomach and irritate the upper lining of stomach, causing heartburn and acid reflux. Tyrosine may also cause other side effects such as dizziness, fatigue, and joint pain.  
There is concern for persons who suffer from certain diseases, such as Grave’s disease, or who are currently taking medications used to treat Parkinson’s disease, depression, or hormone imbalance. Tyrosine supplements should be avoided in these individuals, as it may interact with these drugs. 
In addition, persons who are prone to severe stomachache and migraine headaches should not take L-Tyrosine supplements. Persons taking monoamine oxidase inhibitors (MAOIs) should avoid L-Tyrosine supplements due to its tendency to increase blood pressure, which may result in heart attack or stroke. L-Tyrosine supplements should not be taken by pregnant or women who are breastfeeding. 
Persons on medication for hypertension should be guided by a healthcare provider, as Tyrosine interacts with these medications, increasing one’s heart rate causing other complications. Other drug interactions with Tyrosine include Levadopa, thyroid medications and stimulants.
It is very important to adhere to the recommended dosage of tyrosine supplements, even for healthy individuals, as an excess of tyrosine in the body may place stress on the thyroid gland, causing a condition known as hyperthyroidism—the thyroid glands overproduce thyroid hormones. Symptoms of hyperthyroidism are decreased mental function, fatigue, swelling of the neck, increased sweating, nervousness, and frequent bowel movement. 
Allergic reactions to tyrosine, though rare, do occur; this is usually characterized by skin rashes on the face and neck, itching, swelling, coughing, and difficulty breathing. It is also worthwhile to note that the maximum dosage for the day should not exceed 12g as this may lead to tyrosine toxicity, symptoms of which include insomnia, restlessness, overstimulation, and arrhythmia.back to menu ↑
How To Minimize Exposure
L-Tyrosine is obtained from foods such as cheese, soybeans, beef, eggs, pork chops, salmon, nuts and seeds, lamb and chicken. Tyrosine from these sources are generally safe for healthy individuals, though persons suffering from Phenylketonuria should avoid these foods.
Tyrosine supplements can be avoided by reading supplement labels on “stacks” and multivitamins.back to menu ↑
L-Tyrosine has many benefits and may be considered to be the body’s coping mechanism for dealing with stress and other hormonal imbalances in the body. It is naturally synthesized by the body; deficiency is rare, except in persons affected by certain diseases who have to fulfill their needs with dietary supplements.
While the tyrosine obtained from food sources pose few if any side effects, that obtained from supplements may present mild to moderate side effects, depending on the class of individuals taking the supplement. Tyrosine administered as a supplement must observe strict adherence to the dosage requirements, and any adverse side effects should be reported to your health care provider so proper guidance may be given.