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

Monoamine Oxidase Inhibitors (MAOIs) -- Tyrosine may cause a severe increase in blood pressure in people taking the antidepressant medications known as MAOIs. This rapid increase in blood pressure (also called "hypertensive crisis") can lead to a heart attack or stroke. For this reason, people taking MAOIs should avoid foods and supplements containing tyrosine. MAOIs include:

• Isocarboxazid (Marplan)
• Phenelzine (Nardil)
• Tranylcypromine (Parnate)
• Selegiline

Thyroid hormone -- Tyrosine is a precursor to thyroid hormone, so it might raise levels too high when taken with synthetic thyroid hormones.

Levodopa(L-dopa) -- No one should take tyrosine at the same time as levodopa, a medication used to treat Parkinson's disease because levodopa may interfere with the absorption of tyrosine.