Tyrosine

Tyrosine is a nonessential amino acid that is synthesized in the body from phyenylalanine. Because tyrosine is a precursor of the neurotransmitters norepinephrine and dopamine, both of which regulate mood, a deficiency of tyrosine (leading to a deficiency of norepinephrine) can result in depression.

Tyrosine aids in the the production of melanin (pigment responsible for hair and skin color) and in the functions of the adrenal, thryroid, and pituitary glands. Tyrosine deficiency has been linked to hypothyroidism, low blood pressure, low body temperature, and restless leg syndrome.

Because tyrosine binds unstable molecules that can potentially cause damage to the cells and tissues, it is considered a mild antioxidant. Thus, it may be useful in heavy smokers and in people who have been exposed to harmful chemicals and radiation.

Uses

• Depression. Tyrosine appears to be a safe and effective treatment for depression; however, symptoms of depression recur when tyrosine supplementation is discontinued. Most data on the efficacy of tyrosine in the treatment of depression are anecdotal and have not been proved in scientific studies.
• Stress. Tyrosine seems to relieve the physical symptoms of stress if administered before the stressful situation occurs, though studies on humans are limited.
• Premenstrual syndrome (PMS). Though most data are anecdotal, tyrosine may help reduce the irritability, depression, and fatigue associated with PMS.
• Low sex drive. Tyrosine appears to stimulate the libido.
• Parkinson's disease. Parkinson's disease is treated with L-dopa, which is made from tyrosine; thus, tyrosine supplementation is being studied in people with Parkinson's disease.
• Weight loss. Tyrosine is an appetite suppressant and helps reduce body fat.
• Chronic fatigue and narcolepsy (involuntary sleep). Tyrosine appears to have a mild stimulatory effect on the central nervous system.
• Drug detoxification. Tyrosine appears to be a successful adjunct for the treatment of cocaine abuse and withdrawal; it is often used in conjunction with tryptophan and imipramine (an antidepressant). Successful withdrawal from caffeine and nicotine has also been anecdotally reported.

Dietary Sources

Although tyrosine is found in soy products, chicken, fish, almonds, avocados, bananas, dairy products, lima beans, pumpkin seeds, and sesame seeds, it is difficult to get therapeutic amounts of tyrosine from food. It is also produced from phenylalanine in the body.

Other Forms

Many tyrosine supplements are available.

How to Take It

Tyrosine should be taken 30 minutes before meals three times a day on an empty stomach (with juice or water). Tyrosine should not be taken with other amino acids or with proteins such as milk.

Tyrosine is more effective if it is taken with up to 25 mg of vitamin B₆.

Precautions

Tyrosine should not be taken by patients who are taking monoamine oxidase (MAO) inhibitors for depression or by patients with high blood pressure because it can cause dangerous elevations of blood pressure. Tyrosine may also cause the growth of malignant melanoma (skin cancer) by promoting the division of cancer cells. Migraine headaches and gastrointestinal upset may occur after taking supplements.

Possible Interactions

No harmful drug interactions have been reported.

Supporting Research

Balch JF, Balch PA. Prescriptions for Nutritional Healing. 2nd ed. Garden City Park, NY: Avery Publishing; 1997:42.

Haas EM. Staying Healthy with Nutrition. Berkeley, Calif: Celestial Arts; 1992:51.

Mindell E, Hopkins V. Prescription Alternatives. New Canaan, Conn: Keats Publishing; 1998:398.

Shealy CN. The Illustrated Encyclopedia of Healing Remedies. Shaftesbury, England: Element; 1998:269

Werbach MR. Nutritional Influences on Illness. New Canaan, Conn: Keats Publishing, 1987:162.

Copyright © 2000 Integrative Medicine Communications

The publisher does not accept any responsibility for the accuracy of the information or the consequences arising from the application, use, or misuse of any of the information contained herein, including any injury and/or damage to any person or property as a matter of product liability, negligence, or otherwise. No warranty, expressed or implied, is made in regard to the contents of this material. No claims or endorsements are made for any drugs or compounds currently marketed or in investigative use. This material is not intended as a guide to self-medication. The reader is advised to discuss the information provided here with a doctor, pharmacist, nurse, or other authorized healthcare practitioner and to check product information (including package inserts) regarding dosage, precautions, warnings, interactions, and contraindications before administering any drug, herb, or supplement discussed herein.