L-Tyrosine
L-tyrosine is a nonessential amino acid (protein building block) that the body synthesizes from phenylalanine, another amino acid. Tyrosine is important to the structure of almost all proteins in the body. It is also the precursor of several neurotransmitters, including L-dopa, dopamine, norepinephrine, and epinephrine.
- Reliable and relatively consistent scientific data showing a substantial health benefit.
- Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
- For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
This supplement has been used in connection with the following health conditions:
| Used for | Amount | Why |
|---|---|---|
Stress | 150 mg for every 2.2 lbs (1 kg) of body weight, split into two doses taken before stressful activitiy (take the second dose 40 to 90 minutes after the first) |  [3 stars] Occasionally taking this amino acid before a stressful activity may help maintain your mental capacity. |
Depression | Consult your doctor |  [2 stars] Some people with depression have been found to improve with tyrosine.
|
Phenylketonuria | Consult a qualified healthcare practitioner | [2 stars] Supplementing with L-Tyrosine may help prevent a deficiency caused by the PKU diet and improve behavoir. |
Alcohol Withdrawal (Glutamine, Multivitamin, Phenylalanine, L-Tryptophan) | Refer to label instructions |  [1 star] In double-blind research, alcoholics treated with L-tyrosine combined with DLPA (D,L-phenylalanine), L-glutamine, prescription L-tryptophan, plus a multivitamin had reduced withdrawal symptoms and decreased stress.
|
Parkinson’s Disease | Refer to label instructions | [1 star] L-tyrosine is the direct precursor to L-dopa and therefore could be an alternative to L-dopa therapy, however, it should not be taken with L-dopa as it may interfere with L-dopa transport to the brain. |
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.