Overview

Tyrosine is an amino acid. Amino acids are the building blocks of protein. The body makes tyrosine from another amino acid called phenylalanine. Tyrosine can also be found in dairy products, meats, fish, eggs, nuts, beans, oats, and wheat.

Tyrosine is most commonly used in protein supplements for an inherited disorder called phenylketonuria (PKU). It is also used for alcoholism, cocaine dependence, and memory and thinking skills, but there is no good scientific evidence to support these uses.

How does it work ?

The body uses tyrosine, an amino acid, to make chemical messengers that are involved in conditions involving the brain such as mental alertness.

Uses & Effectiveness ?

Effective for

  • An inherited disorder that increases levels of phenylalanine in the blood (phenylketonuria or PKU). People with PKU are not able to process the amino acid phenylalanine. This amino acid is used by the body to make tyrosine. Because of this, people with PKU can have low levels of tyrosine in the body. To prevent tyrosine levels from becoming too low, people with PKU are advised to consume medical foods containing tyrosine but very little phenylalanine. Tyrosine levels in the blood are regularly measured by physicians.

Possibly Effective for

  • Memory and thinking skills (cognitive function). Research shows that taking tyrosine might improve mental performance, usually under stressful conditions These include cold-induced stress or noise-induced stress.
  • Memory. Research shows that taking tyrosine improves memory during stressful conditions. These include cold-induced stress or multi-tasking. Tyrosine does not seem to improve memory during less stressful situations.

Possibly Ineffective for

  • Athletic performance. Taking tyrosine before running or cycling does not seem to improve strength, stamina, or performance.

Insufficient Evidence for

More evidence is needed to rate the effectiveness of tyrosine for these uses.

Side Effects

When taken by mouth: Tyrosine is LIKELY SAFE when taken in food amounts. It is POSSIBLY SAFE when taken by adults as a medicine, short-term. Tyrosine seems to be safe when taken in doses up to 150 mg/kg daily for up to 3 months. Some people experience side effects such as nausea, headache, fatigue, and heartburn.

When applied to the skin: Tyrosine is POSSIBLY SAFE when applied to the skin.

Special Precautions and Warnings

Pregnancy and breast-feeding: There isn't enough reliable information to know if tyrosine is safe to use when pregnant or breast-feeding. Stay on the safe side and stick to food amounts.

Thyroid disorders: The body uses tyrosine to make thyroxine, a thyroid hormone. Taking extra tyrosine might increase thyroxine levels too much. This could make hyperthyroidism and Graves disease worse. If you have a thyroid disorder, don't take tyrosine supplements.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Levodopa interacts with TYROSINE

    Tyrosine might decrease how much levodopa the body absorbs. By decreasing how much levodopa the body absorbs, tyrosine might decrease the effectiveness of levodopa. Do not take tyrosine and levodopa at the same time.

  • Thyroid hormone interacts with TYROSINE

    The body naturally produces thyroid hormones. Tyrosine might increase how much thyroid hormone the body produces. Taking tyrosine with thyroid hormone pills might cause there to be too much thyroid hormone. This could increase the effects and side effects of thyroid hormones.

Dosing

The following doses have been studied in scientific research:

ADULTS

BY MOUTH:
  • For memory and thinking skills (cognitive function): A single dose of 100-300 mg/kg or 2 grams of tyrosine has been taken before a stressful mental task.
  • For memory: 150-300 mg/kg of tyrosine has been used before a memory task.
  • For an inherited disorder that increases levels of phenylalanine in the blood (phenylketonuria or PKU): Foods and medical foods providing 4-6 grams of tyrosine daily are recommended. Women with PKU who are pregnant or breastfeeding are advised to consume foods providing 6-7.6 grams of tyrosine daily. A doctor will measure tyrosine levels in the blood to make sure they don't become too high or too low. For most people with PKU, additional separate supplementation with free tyrosine is not recommended. It can cause wide variations in the amount of tyrosine in the blood. This could cause unwanted side effects.
CHILDREN

BY MOUTH:
  • For an inherited disorder that increases levels of phenylalanine in the blood (phenylketonuria or PKU): Foods and medical foods providing tyrosine 1.1-6.0 grams daily, depending on age, are recommended from infancy. A doctor will measure tyrosine levels in the blood to make sure they don't become too high or too low. For most people with PKU, additional separate supplementation with free tyrosine is not recommended. It can cause wide variations in the amount of tyrosine in the blood. This could cause unwanted side effects.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2018.