What is L-Tyrosine?
L-Tyrosine is an amino acid that is used to produce noradrenaline and dopamine. Biologically, L-Tyrosine has high significance. Tyrosine is a starting material for the biosynthesis of DOPA, dopamine, catecholamines, melanin, and thyroxine tyramine. All of them are important neurotransmitters responsible for various cognitive functions. Most consumers are interested in its positive effects in reducing environmental stress within oneself and its benefits in phases of extended wakefulness with full performance potential in some groups or professions such as night shifters, managers or exam candidates. Besides L-Tyrosine is known for its inhibitory effects in cold temperature conditions the brain can be exposed to. For example mountaineers or adventure travelers visiting extreme cold places.
How does L-Tyrosine work?
L-Tyrosine is absorbed quickly from the intestine into the blood and remains at its peak approximately 2-4 hours after ingestion. Ingestion of L-Tyrosine can attenuate the development of behavioral abnormalities associated with acute uncontrollable stressors in research animals . L-Tyrosine Is being looked at for its pharmaceutical method within the brain, of alleviating neurological decline in aging persons suffering dementia, with catecholamine decreasing.
Effects of L-Tyrosine
Supplementation of L-Tyrosine appears to have stress relieving effects and may preserve stress-induced memory deficits. Other than its main attribute, L-Tyrosine can promote attention, especially tested on people diagnosed with ADHD. It has the ability to reduce cognitive decline in periods of sleep deprivation . It also has properties to gain cardiovascular health. When L-Tyrosine is taken prior to acute stress situations it is believed and partly scientifically proven to lower blood pressure at the peak of stressor .
Studies on L-Tyrosine
In a study on rats exposed to cold stress, L-Tyrosine has shown to increase noradrenaline (also known as norepinephrine) concentrations in the hippocampus . A reason why researchers think that L-Tyrosine is able to prevent memory loss in humans in situations of acute stress.
Recommended Dosage / Usage Instructions
Recommendations vary, however most sources suggest 500-2000mg approximately 30-60 minutes before any acute sudden stress.
Side-Effects of L-Tyrosine
There may be side effects at higher doses and in rare cases. These can include insomnia, restlessness, anxiety, palpitations or headache. Even rashes, heartburn or upset stomach may occur. Although L-Tyrosine has relatively mild side effects, when experiencing any of the mentioned side-effects a physician should be consulted.
When taking the amino acid levodopa, amongst medication against Parkinson’s disease, L-Tyrosine should not be taken, as their common ability to cross the blood-brain barrier may interfere with each other’s effect. L-Tyrosine is not recommended during pregnancy or lactating mothers.
 - Neurochemical and behavioral consequences of acute, uncontrollable stress: effects of dietary tyrosine - http://www.ncbi.nlm.nih.gov/pubmed/6204715
 - The effects of tyrosine on cognitive performance during extended wakefulness - http://www.ncbi.nlm.nih.gov/pubmed/7794222
 - Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course - http://www.ncbi.nlm.nih.gov/pubmed/10230711
 - Tyrosine administration reduces blood pressure and enhances brain norepinephrine release in spontaneously hypertensive rats - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC383857/
 - Tyrosine improves behavioral and neurochemical deficits caused by cold exposure - http://www.ncbi.nlm.nih.gov/pubmed/11274672