Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| L-Glutamine | L-Tyrosine | |
|---|---|---|
| Category | Amino Acids | Amino Acids |
| Standard Dose | 5-10g daily | 500-2000mg daily |
| Timing | On empty stomach for gut healing. Post-workout for muscle recovery. Dissolves easily in water. | Morning on empty stomach (competes with other large neutral amino acids for BBB transport). 30-60 min before stressful tasks or exercise. |
| Cycle Duration | 8-12 weeks for gut healing; ongoing for maintenance | As needed or cycle 4-8 weeks on, 2 weeks off |
| Evidence Level | strong_human | strong_human |
L-Glutamine is the most abundant amino acid in plasma and skeletal muscle. It is the primary fuel source for enterocytes (intestinal epithelial cells) and rapidly dividing immune cells (lymphocytes, neutrophils). Glutamine maintains intestinal tight junction integrity by modulating tight junction proteins (occludin, claudin-1, ZO-1), preventing intestinal hyperpermeability ('leaky gut'). It serves as a nitrogen shuttle between tissues, is a precursor for nucleotide synthesis (purines and pyrimidines), contributes to gluconeogenesis, and buffers ammonia via glutamine synthetase. During catabolic stress (illness, surgery, intense exercise), glutamine becomes conditionally essential.
5-10g daily
On empty stomach for gut healing. Post-workout for muscle recovery. Dissolves easily in water.
8-12 weeks for gut healing; ongoing for maintenance
L-Tyrosine is the precursor amino acid for catecholamine neurotransmitter synthesis: tyrosine hydroxylase converts tyrosine to L-DOPA (rate-limiting step), which is then converted to dopamine, norepinephrine, and epinephrine. It is also the precursor for thyroid hormones (iodination of tyrosine residues on thyroglobulin produces T3/T4) and melanin (via tyrosinase). Under conditions of acute stress, catecholamine turnover increases dramatically, depleting brain tyrosine pools. Supplementation provides substrate to maintain catecholamine synthesis during stress, sleep deprivation, cold exposure, and cognitive demand.
500-2000mg daily
Morning on empty stomach (competes with other large neutral amino acids for BBB transport). 30-60 min before stressful tasks or exercise.
As needed or cycle 4-8 weeks on, 2 weeks off
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