L-tyrosine is one of 20 amino acids that help build necessary proteins in the body. When supplemented therapeutically, it can help fight fatigue, depression, poor cognitive function, sunburn, and potentially weight gain.
Found in several protein-containing foods, L-tyrosine offers multiple benefits probably because it is a precursor to several powerful substances, including dopamine, adrenaline and noradrenaline, thyroid hormones, and melanin.
Dopamine – This hormone regulates your reward and pleasure centers. It’s also important for memory, motor skills, and mood.
Adrenaline and noradrenalin – These hormones are responsible for your fight or flight response to stress.
Thyroid hormones – These are produced by the thyroid gland and are primarily responsible for regulating metabolism.
Melanin – This pigment gives your skin, hair, and eyes their color. This is the pigment that helps you tan.
Because it helps produce the substances mentioned above, L-tyrosine has several potential benefits.
Protects against stress-induced depression/irritability/fatigue – Stress increases levels of catecholamines, which can deplete your reserve of “feel good” neurotransmitters such as dopamine and adrenalin. L-tyrosine can return those neurotransmitters to normal levels.
Protects against stress-induced cognitive dysfunction – Under stress many people complain of fuzzy thinking or a reduced ability to make decisions. Studies have found having higher levels of L-tyrosine in your system can improve mood and general alertness. Another study found supplementing with L-tyrosine before taking a test improved cognitive flexibility, the ability to switch between tasks or thoughts.
Improves energy and alertness – Because L-tyrosine encourages the production of adrenalin and thyroid hormone, it can increase energy and mental alertness. It has been used to improve alertness during times of sleep deprivation.
May help with weight loss – Small studies indicate L-tyrosine may be helpful with weight loss, again because it can increase production of thyroid hormone and adrenalin.
May help prevent sunburn – Because L-tyrosine encourages melanin production, supplementing with it can help the body produce more melanin for tanning. During summer months, experts recommend taking 1,000-1,500 mg L-tyrosine daily, along with 1,000-1,500 vitamin C, 50 mg vitamin B6, and 4mg copper balanced with 30 mg of zinc to help prevent sunburn.
L-tyrosine is generally regarded as safe, with few side effects reported. Military studies have used doses as high as 20 mg daily safely. That said, there are few studies taking high doses over a long period of time. Most experts caution not using amounts over 1,000 mg daily for periods longer than a few months.
L-tyrosine should not be taken by anyone with hyperactive thyroid conditions as it can increase thyroid hormone production.
Anyone taking Levodopa should consult their doctor before experimenting with L-tyrosine. The amino acid might decrease how much levodopa the body absorbs.