From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

Tyrosine is a non-essential amino acid;[1] it is a precursor to melanin which darkens skin,[1] dopa, which is converted to the neurotransmitters dopamine, noradrenaline (norepinephrine) and adrenaline (epinephrine).[2] Tyrosine is converted to l-dopa by the enzyme tyrosine hydroxylase (TH).[2] Dopamine is important for both pleasure and motivation, and both noradrenaline and adrenaline have a key role in the fight or flight response of the sympathetic nervous system, which is activated by emotional or physical arousal.[2]

Tyrosine is also an important precursor to the thyroid hormones triiodothyronine (T3) and thyroxine (T4).[2]

Tyrosine deficiencies are known to cause hypothyroidism, low blood pressure and a [low body temperature]].[1]

Sources[edit | edit source]

Tyrosine and its precursor phenylalanine are required for the synthesis of coenzyme Q10. People with the genetic condition phenylketonuria (PKU) need tyrosine supplements because they are unable to convert phenylalanine into tyrosine.[2]

ME/CFS[edit | edit source]

Reduced levels of plasma tyrosine have been found in ME/CFS patients.[3][4]

Evidence[edit | edit source]

Two studies of healthy adults have found that tyrosine supplements moderately increased cognitive performance and mental status after prolonged periods without sleep and under intensive military training.[2]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 PubChem. "Tyrosine". pubchem.ncbi.nlm.nih.gov. Retrieved March 5, 2021.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 van der Poll, MCG; Luiking, YC; Dejong, CHC; Soeters, PB (September 2, 2009). "Amino Acids". In Caballero, Benjamin (ed.). Guide to Nutritional Supplements. Oxford, UK: Academic Press. p. 8. ISBN 978-0-12-375661-9.
  3. Georgiades, Evelina; Behan, Wilhelmina M.H.; Kilduff, Liam P.; Hadjicharalambous, Marios; Mackie, Eileen E.; Wilson, John; Ward, Susan A.; Pitsiladis, Yannis P. (August 2003). "Chronic fatigue syndrome: new evidence for a central fatigue disorder". Clinical Science (London, England: 1979). 105 (2): 213–218. doi:10.1042/CS20020354. ISSN 0143-5221. PMID 12708966.
  4. Jones, Mark G.; Cooper, Elizabeth; Amjad, Saira; Goodwin, C. Stewart; Barron, Jeffrey L.; Chalmers, Ronald A. (November 1, 2005). "Urinary and plasma organic acids and amino acids in chronic fatigue syndrome". Clinica Chimica Acta. 361 (1): 150–158. doi:10.1016/j.cccn.2005.05.023. ISSN 0009-8981.