Guest guest Posted May 30, 1999 Report Share Posted May 30, 1999 I have found the information listed below relating to Tyrosine. There was much more out there, but they were intent on selling the product and not advising people. I would advise caution in taking this supplement. Amino acids, in general, can be risky from what I recall of past research. I prefer to get mine in meat, cottage cheese, yogurt and chocolate (!).....among other things. Out of about a dozen articles, there was one mention of Restless Leg Syndrome. Connie, 63, MD L-TYROSINE ------------------------------------------------------------------------------ -- LI90P L-Tyrosine 500mg / 90 caps $10.00 Supports proper mental function - especially mood, alertness, and attentiveness It can: Maintain proper levels of neurotransmitters, that in turn influence mood, concentration, and mental function Contents: % US RDA L-Tyrosine (pharmaceutical grade) 500 mg * http://www.vitalityweb.com/nutrition/L-Tyros.htm ------------------------------------------------------------------------------ -------------------------------------------- L-TYROSINE OVERVIEW: L-tyrosine is not an essential amino acid since it is synthesized (from L-PHENYLALANINE, D-PHENYLALANINE, DL-PHENYLALANINE) in the body. Like L-PHENYLALANINE, D-PHENYLALANINE, DL-PHENYLALANINE, tyrosine is intimately involved with the important brain neurotransmitters epinephrine, norepinephrine and dopamine. Claims for tyrosine are similar to those being made for L-Phenylalanine, D-Phenylalanine, DL-Phenyalanine, although, in some respects, tyrosine appears to be more useful. CLAIMS Positive: 1. Psychic energizer and stress reliever 2. Anti-depressant 3. Effective in the treatment of PMS 4. Addictive-drug detoxifier Negative: 1. May elevate blood pressure 2. Dangerous if combined with anti-depressants containing monoamine oxidase inhibitors 3. Might trigger migraine headaches 4. Might promote growth of malignant melanoma EVIDENCE Related To Positive Claims: 1. Psychic energizer and stress reliever:- Animals subjected to stress in the laboratory have been found to have reduced levels of the brain neurotransmitter norepinephrine. Treating with tyrosine prior to stressing the animals prevents reduction of norepinephrine. Findings such as these led to human tyrosine experiments in which soldiers undergoing various forms of stress were given tyrosine to see what effect it might have on their performance. In one of these experiments conditions were created that simulate rapid ascent to 15,500 feet in light clothing. This dramatically stresses the mind and body and significantly diminishes the oxygen supply to the brain. Some of the soldiers thus stressed were given tyrosine supplements prior to this challenge and some were not. Those who got the tyrosine performed much better on a variety of tests than those who did not get the supplements The tyrosine-dosed soldiers were more alert, efficient, less anxious and had fewer complaints about the physical discomforts of their sudden ascent. They complained less of such things as muscle soreness and headaches and were more resistant to cold. These intriguing studies need follow-up and suggest that tyrosine may provide an attractive alte DNA & RNA tive to some of the psychiatric drugs now commonly used - since tyrosine, by comparison, is much safer. 2. Anti-depressant- Studies such as those cited above, as well as growing anecdotal evidence and clinical observation, suggest that tyrosine may be an effective anti-depressant in some major forms of depression. 3. Effective in the treatment of PMS (premenstrual syndrome: --Again there is a growing body of anecdotal evidence and accumulating clinical observation that tyrosine supplements can be quite helpful in reducing the irritation, depression and tiredness of PMS. This claim needs to be evaluated in a well- designed study. 4. Addictive-drug detoxifier- Tyrosine is now being used, reportedly with some success, to aid in the treatment of and withdrawal from cocaine abuse In one study, tryptophan and tyrosine were used in conjunction with the anti-depressant imipramine to treat chronic cocaine abuse with a reported 75-80 percent success rate. Success was judged to be a reduction of at least 50 percent in cocaine use up to complete discontinuance. Most of those participating in the study said this combination not only blocked the cocaine high but also warded off the severe depression that typically accompanies discontinuance or marked reduction in cocaine intake. A placebo-controlled, double-blind follow-up of this study is planned. Other researchers at UCLA and elsewhere, have also reported favorably on regimens containing tryptophan and tyrosine for the treatment of cocaine abuse Related To Negative Claims: 1. May elevate blood pressure- This has been reported in a few cases. 2. Dangerous if combined with anti-depressants containing monoamine oxidase inhibitors- This combination can produce dangerously elevated blood pressure. 3. Might trigger migraine headaches- There is only scant anecdotal evidence that this might be the case in some migraine sufferers. 4. Might promote growth of malignant melanoma- There is no proof of this but it remains a possibility. This does not mean that tyrosine produces melanoma, a skin cancer, but only that if a melanoma develops due to other reasons, a lot of tyrosine might help nourish the growth. RECOMMENDATIONS: (A) Suggested Intake: --Optimal intake is unknown. For PMS with depression and fatigue as the major symptoms), I recommend 500-milligram doses before each of three meals. If that is ineffective, try 1,000-milligram (1 gram) doses before each meal. For depression I recommend the same regimen. If results are inadequate you may, with the consent of your physician, gradually work up to as much as 12 grams of tyrosine (in divided, premeal doses) daily. To counteract stress, see what results you can get with 1,500 milligrams daily. If more is required, again first consult your physician. ( Source / Form: --There are now many tyrosine supplements the market. © Take With: --Take on an empty stomach. Do not combine with other amino acids. Taking with up to 25 milligrams (no more than 50 milligrams total daily) vitamin B6 may be helpful. (D) Cautionary Note: --Do not take tyrosine if you suffer from migraine headaches and find that this amino acid triggers migraine attacks. Do not take tyrosine with anti-depressants containing monoamine oxidase inhibitors. If a malignant melanoma, is present consider carefully before prescribing tyrosine. If the patient suffers from high blood pressure, tyrosine is not recommended. N-Acetyl-L-Tyrosine is an acetylated, aromatic amino acid, with the chemical formula C 11 H 13 NO 4 L-Tyrosine is found in many of the proteins and enzymes in the body, and has a functional role in transmission of nerve impulses, mood levels, and free radical neutralization. ------------------------------------------------------------------------------ -------------------------------------------- Appearance: Crystals or crystalline powder Color: White Odor: None Taste: Characteristic Specific rotation a20/D: +45 to +49 degrees (47.89 o) Solubility in H20 (transmittance): colorless & clear (99.0 %) Chloride 100 ppm Sulfate (SO4) > 300 ppm Ammonium (NH4) 100 ppm Iron (Fe) 5 ppm Heavy metals (lead) > 30 ppm Arsenic (as As2 03) > I ppm Other amino acids not detected by TLC (2.5 mcg) Loss on drying 0.02% Residue on ignition (sulfated) > 0.3 % (0.01%) Assay 98.0 to 102-0 % ( " .3 %) pH 2.49 Pyrogen test (LAL-test) 0.18 EU / gm Tyrosine is converted into L-Dopa, which is a precursor of the catecholamines dopamine, noradrenaline and adrenaline. Along with phenylalanine, it is a useful antidepressant due to increased production of catecholamines. Increases low blood pressure by vasoconstriction. Involved in tissue pigmentation. Important in formation of thyroid hormone. Caffeine and tryptophan reduce tyrosine levels. One to six grams elemental tyrosine daily, divided morning and evening. No toxicity noted for L-Tyrosine (natural). D-Tyrosine (synthetic) can be toxic. WARNING: Should not be used when MAOs (monoamine oxidases) are prescribed, or when cancerous melanoma is present. Deliberate tyrosine and phenylalanine starvation may be important in melanomas and glioblastoma multiforme. Large amounts of valine or tryptophan with meals can probably achieve this. High serum levels of tyrosine are associated with migraine headaches, high blood pressure and schizophrenia. Melanin may be a gene-toxic metabolite of tyrosine; 500 mg of vitamin C daily may prevent its accumulation for pregnant women. Braverman, , The Healing Butrients Within, Keats Publishing Inc., New Canaan, CT, 1987 Gelenberg A.J., Tyrosine for the treatment of depression, Am. J. Psychiatry, vol. 137, p. 622, 1980 ------------------------------------------------------------------------------ ------------------------------------------- Tyrosine An Amino Acid Description: Tyrosine is a nonessential amino acid derived from phenylalanine. Plants/Foods: Avocado Cheese Chicken Chocolate Cottage cheese Duck Egg Granola Oat flakes Pork Ricotta Turkey Wheat germ Whole milk Wild game Yogurt Physiologic Functions: Increases appetite in small doses Increases libido, due to increased catecholamine levels Precursor to hormones such as thyroid and catecholestrogens Precursor for melanin Precursor to neurotransmitters norepinephrine, epinephrine and dopamine Reduces appetite in large doses Clinical Indications: Depression Hypothyroidism Obesity PMS Fatigue due to stress Parkinson's (combined with Sinemet) Restless leg syndrome Substance addiction Signs and Symptoms of Deficiency: Increased appetite Pigment abnormalities Causes of Deficiencies: Inborn errors of tyrosine metabolism Contraindications: Schizophrenia Toxicity and Side Effects: Do not take in conjunction with MAO inhibitors Toxicity is almost nonexistent with tyrosine alone Quote Link to comment Share on other sites More sharing options...
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