L-tyrosine

L-酪氨酸 · 门满了才轮到它

Place · Level 3 · Nootropics

Connected to · 2

synergy · 1

Nervous
Tyrosine shares the LAT1 door into the brain with BCAA and tryptophan; hydroxylase is near saturation at rest, so extra tyrosine at the door only refills catecholamines while they are being spent.

contrast · 1

L-Theanine
L-theanine also uses LAT1, but it taps glutamate noise, not the catecholamine store. Same door, different enzyme after it.

一扇门, 好几种氨基酸在排队

Stop 1/4

One door, several amino acids in line

Tyrosine reaches the brain through the large-neutral-amino-acid transporter (LAT1) at the blood-brain barrier. The same door also takes tryptophan, phenylalanine, and the branched-chain amino acids leucine, isoleucine and valine. They compete for seats. They do not each have a private lane.

Fernstrom 2013 writes the competition hard: raise blood tyrosine and brain tyrosine uptake rises; raise blood BCAA and both tyrosine and tryptophan uptake fall. The steps that turn tyrosine into catecholamines and tryptophan into serotonin track what got through the door.

This island is not how magical a capsule is. It is which amino acid currently occupies the door. The nervous-system island already used BCAA crowding out tryptophan for this same door. Here the tyrosine side of that line is filled in.

Read story

Educational content, not medical advice — consult a clinician.

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L-tyrosine

L-酪氨酸 · 门满了才轮到它

Place · Level 3 · Nootropics

Connected to · 2

synergy · 1

Nervous
Tyrosine shares the LAT1 door into the brain with BCAA and tryptophan; hydroxylase is near saturation at rest, so extra tyrosine at the door only refills catecholamines while they are being spent.

contrast · 1

L-Theanine
L-theanine also uses LAT1, but it taps glutamate noise, not the catecholamine store. Same door, different enzyme after it.

一扇门, 好几种氨基酸在排队

Stop 1/4

One door, several amino acids in line

Tyrosine reaches the brain through the large-neutral-amino-acid transporter (LAT1) at the blood-brain barrier. The same door also takes tryptophan, phenylalanine, and the branched-chain amino acids leucine, isoleucine and valine. They compete for seats. They do not each have a private lane.

Fernstrom 2013 writes the competition hard: raise blood tyrosine and brain tyrosine uptake rises; raise blood BCAA and both tyrosine and tryptophan uptake fall. The steps that turn tyrosine into catecholamines and tryptophan into serotonin track what got through the door.

This island is not how magical a capsule is. It is which amino acid currently occupies the door. The nervous-system island already used BCAA crowding out tryptophan for this same door. Here the tyrosine side of that line is filled in.

Read story

Educational content, not medical advice — consult a clinician.