L-Tyrosine is an amino acid precursor metabolized by the enzyme Tyrosine Hydroxylase into Levodopa and subsequently Dopamine and norepinephrine (both possible nootropic chemicals). Dopamine and norepinephrine antagonists, reuptake inhibitors and precursors have been shown to enhance concentration, drive, and most importantly working memory and executive function via chemical signalers in the prefrontal cortex; the full range of dopamine and norepinephrine functionality still remains unknown.
So, what are the benefits of L-Tyrosine exactly?
•Increased libido through elevated plasma neurotransmitter levels
•Decreased stress levels through regulation of cortisol production
•Increased drive and focus
•Improved working memory and executive function
•May improve symptoms of depression
Although this amino acid appears at face-value to be a cheap nootropic and a natural way of increasing plasma neurotransmitter levels – there a number of complexities in its consumption. L-tyrosine in its unadulterated form lacks significant bioavailability – with a large % of it being lost in the digestive system. L-tyrosine also competes poorly in intestinal absorption against other amino acids. Elevated brain-dopamine levels compete for absorption with serotonin and may trigger mild symptoms of depression. A significant portion of L-tyrosine is deanimated in first-pass hepatic metabolism through the MAO-A/B enzymes.
The University of Maryland Medical Center recommends 500mg-1500mg of L-tyrosine up to three times daily for the relief of stress and anxiety (and potentially as a nootropic). I would recommend ingestion on an empty stomach, with a carbohydrate drink coupled with vitamin C and a B vitamin complex for maximum absorption. For the expert consumer, the purchase of Acetyl-l-tyrosine is preferred due to its greater stability, bioavability and lower doses (250mg per dose)
My l-tyrosine experiences were mainly negative, but this is not to say they will be for you. I believe I am deficient in serotonin and hence increased levels of dopamine lead to anxiety. L-tyrosine at 500mg three times daily increased my motivation levels, but also exposed me to significantly increased anxiety, and rebound depression some 3-4 hours after an initial dosing. All in all I would not recommend this amino-acid to those with a similar neurological disposition to my own.Still… this nootropic agent may be more suitable for you. So go ahead and add it to your nootropics stack and leave feedback!