L-Tyrosine for Weight Control
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.
Why Do Dieters Use It?*
Some dieters say that L-tyrosine helps stimulate weight loss.
What Do the Advocates Say?*
Since it is a precursor to substances like epinephrine, norepinephrine, and dopamine, L-tyrosine may be a good supplement choice for those trying to lose weight because, theoretically, it may help speed metabolism. However, it should only be considered for people who also suffer from symptoms such as fatigue and depression.
There are no studies specifically showing that L-tyrosine helps to promote weight loss.
L-tyrosine is best taken without food. Because it can be stimulating, especially when used in large amounts, it should not be taken in the evening. As is the case when supplementing with any individual amino acid, it’s possible to upset the balance by taking just one.
How Much Is Usually Taken by Dieters?
Most people should not supplement with L-tyrosine. Some human research with people suffering from a variety of conditions used 100 mg per 2.2 pounds of body weight, equivalent to about 7 grams per day for an average-sized person. The appropriate amount to use in people with PKU is not known, therefore, the monitoring of blood levels by a physician is recommended.