Amino Acid
L-Tyrosine
Also known as: Tyrosine, L-Tyrosine (Thyroid Support), 4-hydroxyphenylalanine
B
Evidence
Precursor to dopamine, norepinephrine, and thyroid hormones. Supports focus and stress resilience.
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
Known interactions
Evidence notes
Supports catecholamine synthesis
Grade B: Some human trials support key claims; further confirmation needed.
Related in Amino Acid
Check a full stack
Formulate's free interaction checker lets you paste in any combination of supplements and medications at once — every pairing flags severity, timing, and cited evidence.
Open the checkerMedical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.