Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Iodine (from Kelp or Potassium Iodide) | L-Tyrosine | |
|---|---|---|
| Category | Minerals | Amino Acids |
| Standard Dose | 150-300 mcg daily (RDA: 150 mcg; upper range for optimization) | 500-2000mg daily |
| Timing | Morning with food. | Morning on empty stomach (competes with other large neutral amino acids for BBB transport). 30-60 min before stressful tasks or exercise. |
| Cycle Duration | ongoing | As needed or cycle 4-8 weeks on, 2 weeks off |
| Evidence Level | strong_human | strong_human |
Iodine is the essential substrate for thyroid hormone synthesis. Thyroid peroxidase (TPO) uses iodine to iodinate tyrosine residues on thyroglobulin, producing monoiodotyrosine (MIT) and diiodotyrosine (DIT), which couple to form T4 (3,5,3',5'-tetraiodothyronine) and T3 (3,5,3'-triiodothyronine). Iodine is concentrated by the sodium-iodide symporter (NIS) in the thyroid, breast tissue, gastric mucosa, salivary glands, and choroid plexus. Beyond thyroid function, iodine has direct antimicrobial properties, modulates immune function, and may play a role in breast tissue health via iodolactone-mediated apoptosis.
150-300 mcg daily (RDA: 150 mcg; upper range for optimization)
Morning with food.
ongoing
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
Take our free assessment to get personalized recommendations based on your health goals, current stack, and biomarkers.
Get Your Free Protocol →or take the assessment →