L-tyrosine is naturally found in many foods, so it is generally safe when taken in the amounts commonly found in foods.
Taking L-tyrosine as a supplement may improve alertness and cognitivecognitiverelating to the ability to think, reason, remember, and discern function in physically stressful situations such as sleep deprivation and cold temperatures. Taking L-tyrosine may also improve working memory in a multitasking environment.
L-tyrosine is generally safe and well tolerated, but should only be used on a short-term, occasional basis. Side effects that have been reported include nausea, fatigue, headache, and heartburn.
L-tyrosine may reduce the effectiveness of levodopa, a medication used by people with Parkinson's disease, by decreasing its absorption. Therefore, these 2 medications should be taken at least 2 hours apart.
If you take thyroid hormone medications and have hyperthyroidism or Graves' disease, talk to your doctor before taking L-tyrosine. L-tyrosine is a precursor to thyroxine, a type of thyroid hormone, and may increase thyroid hormone levels.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.