N-Acetyl L-Tyrosine

Tyrosine is an amino acid the body produces from phenylalanine (another type of amino acid). Found in a number of foods including meat, fish, eggs, dairy, eggs, nuts, legumes, and oats, tyrosine is available in dietary supplement form as well.1

Tyrosine is essential to your body’s production of melanin (a type of pigment) and several key brain chemicals including dopamine and norepinephrine. It also plays an important role in the function of the adrenal, thyroid, and pituitary glands, which are involved in producing and regulating your hormones.

Tyrosine is also commonly known as L-Tyrosine and N-acetyl L-tyrosine (NALT).


One of the most common uses of tyrosine supplements is the treatment of a genetic disorder known as phenylketonuria.2 In people with phenylketonuria, the body is unable to process phenylalanine properly and, as a result, cannot produce the tyrosine it needs to function.

In alternative medicine, tyrosine supplements are often touted as a natural remedy for a range of health problems, including:

  • Alzheimer’s disease
  • Attention Deficit Hyperactivity Disorder
  • Chronic fatigue syndrome
  • Depression
  • Heart disease
  • Parkinson’s disease
  • Premenstrual syndrome
  • Stress
  • Stroke

Some alternative medicine proponents claim that tyrosine supplements can also help suppress appetite, promote weight loss, increase mental alertness, improve memory, and enhance athletic performance.

Health Benefits

Although relatively few studies have tested the effects of taking tyrosine supplements, there’s some evidence that tyrosine may offer certain health benefits. Here’s a look at several key findings from the available research:


For a report published in the Cochrane Database of Systematic Reviews in 2013, investigators analyzed the available clinical trials on the use of tyrosine supplements in people with phenylketonuria.2

Looking at data from six clinical trials with a total of 56 phenylketonuria patients, the report’s authors found that blood levels of tyrosine were significantly higher in participants receiving tyrosine supplements compared to those given a placebo.

Brain Function

Some studies show the use of tyrosine supplements may boost brain function under certain conditions.

A 2010 study published in the Journal of the International Society of Sports Nutrition found that tyrosine supplementation led to significantly greater improvements in focus and alertness after exhaustive exercise.3 The study included 19 healthy college students, each of whom was given either a tyrosine supplement or a placebo for a four-week period.

In addition, a 2007 study of 19 people published in Physiology & Behavior found that use of tyrosine supplements helped protect against the detrimental effects of severe cold exposure on cognitive performance and memory.4

Exercise Performance

So far, studies examining tyrosine’s effects on exercise performance have yielded mixed results.

In a 2011 study from the European Journal of Applied Physiology, for example, tests on eight healthy male volunteers found that consumption of a tyrosine-enriched drink helped increase endurance while exercising in the heat.5

However, a 2016 study published in the International Journal of Sports Nutrition and Exercise Metabolism found that tyrosine supplementation failed to protect against exhaustion while exercising in a warm environment.6