What other names is Tyrosine known by?
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, Tirosina, Tyr, Tyrosinum, 2-amino-3-(4-hydroxyphenyl)propionic acid.
What is Tyrosine?
Tyrosine is one of the amino acids, which are the building blocks of protein. The body makes tyrosine from another amino acid called phenylalanine. Tyrosine can also be found in dairy products, meats, fish, eggs, nuts, beans, oats, and wheat.
Tyrosine is used in protein supplements
to treat an inherited disorder called phenylketonuria
(PKU). People who have this problem can't process phenylalanine properly, so as a result they can't make tyrosine. To meet their bodies' needs, supplemental tyrosine is given.
People take tyrosine for depression
, attention deficit disorder (ADD), attention deficit-hyperactivity
), the inability to stay awake (narcolepsy
), and improving alertness following sleep
deprivation. It is also used for stress
, premenstrual syndrome
), Parkinson's disease
, Alzheimer's disease
, chronic fatigue syndrome
), alcohol and cocaine
withdrawal, heart disease
), loss of interest in sex, schizophrenia
, and as a suntan agent and appetite suppressant.
Some people also apply tyrosine to the skin to reduce age-related wrinkles
- Phenylketonuria (PKU). People with PKU are not able to process the amino acid phenylalanine, which is used by the body to make tyrosine. Because of this, people with PKU can have low levels of tyrosine in the body. People with PKU are advised to consume 6 grams of tyrosine per 100 grams of protein to improve tyrosine levels in the body.
Possibly Effective for...
- Mental performance. Some early research suggests that taking tyrosine 2 hours before testing does not improve mood or speed of reaction to visual or noise stimuli in healthy people. However, several studies show that tyrosine improves mental performance under stressful conditions, such as military training, cold-induced stress, or noise-induces stress.
- Memory. Some early research suggests that taking tyrosine 2 hours before testing does not improve memory in healthy people. However, several studies show that tyrosine improves memory under stressful conditions, such as cold-stress or multitasking.
- Improving alertness following the loss of sleep. Taking 150 mg/kg of tyrosine seems to help people who have lost a night's sleep stay alert for about 3 hours longer than they otherwise would. Also, early research suggests that tyrosine improves memory and reasoning in people who are sleep-deprived.
Possibly Ineffective for...
- Attention deficit disorder (ADD). Taking tyrosine by mouth does not seem to improve symptoms of adult ADD.
- Attention deficit-hyperactivity disorder (ADHD). Taking tyrosine by mouth does not seem to improve symptoms of childhood ADHD.
- Depression. Taking tyrosine by mouth does not seem to improve symptoms of moderate depression.
- Exercise performance. Taking tyrosine before participating in treadmill walking with a load carriage does not seem to improve strength or endurance. Also, taking tyrosine, alone or with polydextrose 70, does not seem to improve heart rate or performance during a cycling test.
Insufficient Evidence to Rate Effectiveness for...
- Alcoholism. Early research suggests that taking a combination 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.
- Cocaine dependence. Early research suggests that taking L-tyrosine in the morning and L-tryptophan at night does not reduce drug cravings or withdrawal symptoms in people with cocaine dependence.
- Dementia. Early research suggests that taking a 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.
- High blood pressure (hypertension). Early research suggests that taking tyrosine by mouth does not affect blood pressure in patients with slightly high blood pressure.
- Excessive sleepiness (narcolepsy). Research suggests that taking tyrosine by mouth might reduce some symptoms of narcolepsy, such as feelings of tiredness, based on patient ratings. However, it does not seem to improve most symptoms of narcolepsy based on clinical assessment.
- Schizophrenia. Early research suggests that taking L-tyrosine along with the drug molindone for 3 weeks does not improve symptoms of schizophrenia better than molindone alone.
- 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. 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 3 months to facial skin aged by sunlight seems to improve fine and coarse wrinkling, yellowing, roughness, and skin tone.
- 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.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).