Posted 3/16/07CLICK TO PRINT

NAME: Tyrosine, L-Tyrosine
DESCRIPTION: Tyrosine is a conditionally essential protein amino acid; meaning while that the body usually produces enough on its own, in some situations (such as in phenylketonuria - or PKU - a genetic disorder in which the body cannot process the amino acid phenylalanine - where healthy bodies derive their source for tyrosine) it may need outside assistance (dietary intake or supplementation) to attain enough for its physiological needs.

L-tyrosine is involved with protein synthesis.

L-tyrosine is a precursor for the synthesis of the neurotransmitters epinephrine, norepinephrine and dopamine (which regulate mood), the thyroid hormones thyroxine and triiodothyronine, and the pigment melanin.

Tyrosine is also involved in the synthesis of enkephalins, substances that have pain-relieving effects in the body, and is considered a mild antioxidant.

FUNCTION: Used primarily as an antidepressant. This is likely due to its efffect on synthesis of the neurotransmitters norepinephrine and dopamine: elevated brain levels of which are thought to be associated with antidepressant effects.
SOURCES: Tysorine is found in: cheese, soy products, chicken, fish, peanuts, almongs, avocados, bananas, milk pumpkin and sesame seeds
DOSAGE: Those who use supplemental L-tyrosine typically take 500 to 1500 mg daily.

Tyrosine supplements should be taken at least 30 minutes before meals, divided into three daily doses. They should be taken with a multivitamin-mineral complex: vitamins B6, B9 (folate), and copper help convert L-tyrosine into important brain chemicals.

DATA: Tyrosine has been investigated for its ability to affect various conditions. Some studies have shown a benefit for depression when tyrosine is used in conjunction with either tryptophan or its precursor, 5-HTP (5-hydroxytryptophan). Studies done in the 70s among individuals deficient in the amino acid showed some benefit, while a study using tyrosine alone for depression found no benefit, however, they did not combine it with 5-HTP or tryptophan.

More recent studies have shown little positive effect on attention deficit disorder, narcolepsy, or neuropsychological function in subjects with phenylketonuria (PKU).

Tyrosine has, however, shown some promise in relieving the effects of environmental stress (exposure to harmful chemicals - such as from smoking - and radiation).

It has been used successfully in addition to conventional treatment for cocaine abuse and withdrawal.

CAUTIONS: Do not take with MAO inhibitors.

Do not use if you have a history of malignant melanoma. Also not advised for those with bipolar disorder nor for women who are pregnant, lactating or suspect a pregnancy.

University of Maryland's Center for Integrative Medicine's website entry on tyrosine.
Tyrosine 500 (Jarrow) Each bottle, 100 capsules. Each capsule, 500 mg of L-Tyrosine.
PRODUCT NOTES: Suggested use of Tyrosine 500: Take 1-2 capsules immediately upon rising (empty stomach). You are encouraged to take it with a bit of juice as a carbohydrate source. For best effects, take with tryptophan or 5-HTP and use 3 times per day.
DISCLAIMER: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.