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Medically reviewed by Last updated on Nov 17, 2021.

What are other common names?

  • 2-Amino-3-(4-Hydroxyphenyl) Propionic Acid
  • 2-­Acetylamino-­3-­(4­-Hydroxyphenyl)-­Propanoic Acid
  • 4-hydroxyphenylalanine
  • Acetyl-L-Tyrosine
  • Acétyl­-L­-Tyrosine
  • C9H11NO3
  • L-Tyrosine
  • N-Acetyl-L-Tyrosine
  • N-Acetyl-Tyrosine
  • N-Acétyl­-Tyrosine
  • N­-Acétyl L-­Tyrosine
  • Tirosina
  • Tyr
  • Tyrosinium

What is this product used for?

Tyrosine may help improve the ability to think during times of stress.

What are the precautions when taking this product?

  • Always check with your doctor before you use a natural product. Some products may not mix well with drugs or other natural products.

  • This product may interfere with some lab tests. Be sure to talk with your doctor about this and all drugs you are taking.

  • Be sure to tell your doctor if you are pregnant, plan on getting pregnant, or are breastfeeding. You will need to talk about the benefits and risks of using this natural product.

  • Do not use this product if you have an overactive thyroid or a condition called Graves disease.

  • Do not use this product if you are taking drugs called MAO inhibitors. These are drugs like isocarboxazid, phenelzine, and tranylcypromine.

  • Take extra care if you are taking drugs that affect dopamine levels. These are drugs like levodopa-carbidopa, ropinirole, and pramipexole.

  • Take extra care if you are taking drugs that affect your thyroid. These are drugs like desiccated thyroid, levothyroxine, liothyronine, and liotrix.

  • Take extra care and check with your doctor if you have:

    • Thyroid problems

    • Kidney disease

    • Parkinson's disease

    • Low mood

    • Migraine headaches

What should I watch for?

  • Upset stomach

  • Feeling nervous or anxious

  • Headache

When do I need to call the doctor?

  • Signs of a very bad reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat. Go to the ER right away.

  • Very bad throwing up

  • Very bad loose stools

Last Reviewed Date


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