If you are currently being treated with any of the following medications, you should not use tyrosine supplements without first talking to your healthcare provider.

Antidepressant Medications, Monoamine Oxidase Inhibitors (MAOIs)
Tyrosine may cause a severe increase in blood pressure in people taking MAOIs (such as phenelzine, tranylcypromine, pargyline, and selegiline). This severe increase in blood pressure (also called "hypertensive crisis") can lead to a heart attack or stroke. For this reason, individuals taking MAOIs should foods and supplements containing tyrosine.

Appetite suppressant Medications

In a rat study, L-tyrosine increased the appetite-suppressant effects of phenylpropanolamine, ephedrine, and amphetamine. More research is needed to determine whether L-tyrosine produces similar results in humans.

Morphine
Although the application for humans is unclear, animal studies suggest that tyrosine increases the pain-relieving effects of morphine.

Levodopa
Tyrosine should not be taken at the same time as levodopa, a medication used to treat Parkinson's disease because levodopa may interfere with the absorption of tyrosine.