Amino Acid
L-Tyrosine
Also known as: Tyrosine, L-Tyrosine (Thyroid Support), 4-hydroxyphenylalanine
Precursor to dopamine, norepinephrine, and thyroid hormones. Supports focus and stress resilience.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Daily target & upper limit
1000 mg / dayL-Tyrosine has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
L-Tyrosine dosage reference →Primary uses
- Focus
- Stress resilience
- Thyroid support
- Cognitive performance
- Thyroid hormone synthesis
- Cognitive function
- Dopamine precursor
How it works
- Precursor to L-DOPA then dopamine
- Supports norepinephrine synthesis
- Thyroid hormone precursor
Dosage
- Typical range
- 500-2000 mg daily
- Timing
- Morning or before stressful tasks
- With food
- Away from protein meals
- Duration
- As needed, cycling may help
- Special populations
- High stress, cognitive demands
Forms
- Capsules
- Powder
- L-Tyrosine powder
- NALT (N-Acetyl)
Safety
Common side effects
- Insomnia if taken late
- Anxiety at high doses
Contraindications
- MAOIs
- Hyperthyroidism
Products containing L-Tyrosine
Top-scoring supplements in our catalog that list L-Tyrosine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Known interactions
Evidence notes
Supports catecholamine synthesis
Grade B: Some human trials support key claims; further confirmation needed.
L-Tyrosine compared head-to-head
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.