Health Guide


What is it?

Tyrosine is an amino acid which is present in protein in the diet and is used as a supplement for Parkinson's disease, phenylketonuria, and to improve memory.

Other names for Tyrosine include: L-Tyrosine

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breastfeeding
  • have kidney or liver disease
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much Tyrosine you should take. The amount depends on the strength of the medicine and the reason you are taking Tyrosine. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take Tyrosine without talking to your doctor first if you are taking:

  • Medicines for depression or Parkinson's disease (monoamine oxidase inhibitors (MAOIs), examples: selegiline (Deprenyl(R), Eldepryl(R)); isocarboxazid (Marplan(R)))
  • Levodopa (Bendopa(R), Sinemet(R))
  • Methylphenidate (Ritalin(R))


  • Do not use Tyrosine if you are pregnant or breastfeeding (4,5)
  • Do not use Tyrosine if you have diabetes (4)
  • Do not use in infants and children without the supervision of a doctor (4)

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Changes in heart rate (6)
  • Headache, fatigue (7,8)
  • Mood changes, anger, irritability (8)
  • Stomach upset or pain, nausea, heartburn (8)


1. Neri DF, Wiegmann D, Stanny RR et al: The effects of tyrosine on cognitive performance during extended wakefulness. Aviat Space Environ Med 1995; 66(4):313-319.

2. Growdon JH, Melamed E, Logue M et al: Effects of oral L-tyrosine administration on CSF tyrosine and homovanillic acid levels in patients with Parkinson's disease. Life Sci 1982; 30(10):827-832.

3. Bross R, Ball RO, Clarke JTR et al: Tyrosine requirements in children with classical PKU determined by indicator amino acid oxidation. Am J Physiol Endocrinol Metab 2000; 278(2):E195-E201.

4. Tyrrell H & Maher T: Tyrosine: Food supplement or therapeutic agent? J Nutr Env Med 1998; 8(4):349-359.

5. Lewis SA, Lyon IC & Elliot RB: Outcome of pregnancy in the rat with mild hyperphenylalaninaemia and hypertyrosinaemia: implications for the management of "human maternal PKU." J Inherit Metab Dis 1985; 8(3):113-117.

6. Gelenberg A, Wojcik J, Falk W et al: Tyrosine for depression: a double-blind trial. J Affective Disorders 1990; 19(2):125-132.

7. Reimherr FW, Wender PH, Wood DR et al: An open trial of L-tyrosine in the treatment of attention deficit disorder, residual type. Am J Psychiatry 1987; 144(8): 1071-1073.

8. Wood DR, Reimherr FW & Wender PH: Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharm Bull 1985; 21(1):146-149.

9. Elwes R, Chesterman L, Jenner P et al: Treatment of narcolepsy with L-tyrosine: double-blind placebo-controlled trial. Lancet 1989; 2(8671):1067-1069.

10. Eriksson T, Granerus AK, Linde A et al: 'On-off' phenomenon in Parkinson's disease: relationship between dopa and other large neutral amino acids in plasma. Neurology 1988; 38(8): 1245-1248.

11. Juncos JL, Fabbrini G, Mouradian MM et al: Dietary influences on the antiparkinsonian response to levodopa. Arch Neurol 1987; 44(10):1003-1005.

12. Woods S & Meyer J: Exogenous tyrosine potentiates the methylphenidate-induced increase in extracellular dopamine in the nucleus accumbens: a microdialysis study. Brain Res 1991; 560(1-2):97-105.

Last Updated: 10/4/2009
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