L-Tyrosine (Thyroid Support)
The amino acid backbone of thyroid hormones and catecholamine neurotransmitters.
Also known as: Tyrosine • 4-Hydroxyphenylalanine
Overview
L-Tyrosine is a non-essential amino acid that serves as the structural backbone of thyroid hormones. Thyroid peroxidase enzyme iodinates tyrosine residues on thyroglobulin to form T3 and T4. Tyrosine is also the precursor to dopamine, norepinephrine, and epinephrine, supporting both thyroid function and stress resilience.
Key Benefits
Thyroid Hormone Precursor
Provides the amino acid backbone for T3 and T4 synthesis.
Stress Resilience
Replenishes catecholamines depleted under stress, maintaining cognitive performance.
Cognitive Function Under Stress
Improves working memory and attention during sleep deprivation and acute stress.
Dopamine Support
Precursor to dopamine, supporting motivation and mood.
Dosage & How to Take
500-2000 mg daily.
| Purpose | Dose | Notes |
|---|---|---|
| Thyroid support | 500-1000 mg/day | With iodine and selenium |
| Cognitive/stress support | 1000-2000 mg/day | On empty stomach |
Best Time to Take
Morning on empty stomach.
With or Without Food
Best on empty stomach for brain effects; with food for thyroid.
Forms & Bioavailability
| Form | Absorption | Best For | Notes |
|---|---|---|---|
| L-Tyrosine | Good | Standard use, most researched | Free-form amino acid. |
| N-Acetyl L-Tyrosine (NALT) | Lower | Better solubility | Less efficiently converted to tyrosine. |
Side Effects & Safety
Common
- Generally well tolerated
Rare
- Headache
- GI discomfort
- Restlessness
Contraindications
- Hyperthyroidism
- Graves' disease
- MAOIs
Interactions
May enhance thyroid hormone production.
Risk of hypertensive crisis.
May compete for absorption.
Scientific Research
Tyrosine and cognitive performance under stress
Multiple studies showed tyrosine supplementation improved cognitive performance during acute stress, cold exposure, and sleep deprivation.
Food Sources
Frequently Asked Questions
Medical Disclaimer
This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.