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    Amino AcidsSynthetic

    L-Tyrosine

    Also known as: Tyrosine

    Aromatic amino acid converted by tyrosine hydroxylase to L-DOPA, then to dopamine, noradrenaline, and adrenaline; replenishes catecholamine substrate during high demand.

    Last reviewed: 2026-06-23 · 1 indexed study

    Evidence Score
    64/100
    Cognitive performance under stressFocusCatecholamine supportCold-stress resilience
    Data Completeness3/4 · 75%
    Evidence ScoreDosageSafetyLinked Studies

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    Overview

    L-Tyrosine is a non-essential amino acid precursor to dopamine, noradrenaline, and adrenaline that supports cognitive performance under acute stress (sleep deprivation, cold, multitasking).

    Mechanism & Function

    Mechanism of Action

    Replenishes catecholamine precursor pool under acute stress, preserving cognitive performance in tasks limited by dopamine/noradrenaline turnover.

    Physiological Role

    Most validated in military/cold/sleep-deprived contexts; modest ergogenic value in standard training, but useful for shift workers and high-cognitive-load athletes.

    Primary Pathways

    Tyrosine hydroxylase substrateCatecholamine synthesisThyroid hormone precursor

    Performance / Health Relevance

    RCT evidence supports cognitive preservation under acute stress; effects in well-rested users are smaller.

    Evidence Review

    Overall64/100
    Human Clinical72/100
    Meta-Analysis60/100
    Mechanistic85/100
    Real-World62/100
    Safety90/100

    Practical Use & Dosage

    Minimum Effective Dose
    500 mg
    Optimal Range
    100–150 mg/kg (typically 7–12 g) acute pre-stress
    Upper / Caution Level
    ~12 g acute
    Timing
    30–60 min pre-stressor
    Best Format
    Powder, capsule
    Bioavailability
    High — readily absorbed.
    Absorption Considerations
    Active intestinal transport via large neutral amino acid transporter; peak plasma 1–2 h.

    Safety & Interactions

    Side Effects

    • •Mild headache
    • •Nausea at high doses
    • •Insomnia if late dosing

    Contraindications

    • Hyperthyroidism
    • MAOI use
    • Melanoma

    Drug Interactions

    • •MAOIs
    • •Levodopa
    • •Thyroid hormones

    Who Should Avoid

    • •Phenylketonuria

    Monitoring

    None routine.

    Frequently Asked Questions

    Auto-generated from indexed evidence — dosage, safety, interactions, and more.

    When is L-Tyrosine typically used or indicated?

    L-Tyrosine is most commonly used for: Cognitive performance under stress, Focus, Catecholamine support, Cold-stress resilience. Most validated in military/cold/sleep-deprived contexts; modest ergogenic value in standard training, but useful for shift workers and high-cognitive-load athletes.

    How does L-Tyrosine work?

    Replenishes catecholamine precursor pool under acute stress, preserving cognitive performance in tasks limited by dopamine/noradrenaline turnover.

    What is the recommended dose of L-Tyrosine?

    The optimal range is 100–150 mg/kg (typically 7–12 g) acute pre-stress. with a minimum effective dose of 500 mg. Best taken: 30–60 min pre-stressor. Upper / caution level: ~12 g acute.

    What are the side effects of L-Tyrosine?

    Reported side effects include: Mild headache; Nausea at high doses; and Insomnia if late dosing. Monitoring: None routine.

    Does L-Tyrosine interact with medications?

    Known or theoretical interactions: MAOIs; Levodopa; and Thyroid hormones. Always check with a clinician before combining with prescription medication.

    Who should avoid L-Tyrosine?

    L-Tyrosine is generally not recommended for: Phenylketonuria; Hyperthyroidism; MAOI use; and Melanoma.

    How strong is the evidence for L-Tyrosine?

    Evidence level: Moderate (overall score 64/100), based on 1 indexed study on SuppIndex.

    Research & References (1)

    L-Tyrosine and cognitive performance under stress: review

    Systematic Review2015Moderate
    PubMed

    Consistent benefit for working memory and reaction time under sleep deprivation, cold, multitasking.

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    Research Overview

    Moderate Evidence
    1Total Studies
    0Human Trials
    0Meta-Analyses
    2015Latest Study
    0Animal / In Vitro
    0Athlete Studies
    Primary data sourceMixed
    Pooled evidence (meta-analysis / systematic review)Yes

    Cite this ingredient

    One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.

    Stable URL

    https://thesuppindex.com/ingredients/l-tyrosine

    SuppIndex. (2026). L-Tyrosine: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/l-tyrosine

    Based on 1 indexed studies · Evidence level: Moderate.

    Goal Ratings

    Focus
    Cognition
    Stress

    Stack Compatibility

    Synergistic with caffeine and L-theanine; avoid with protein meals (transport competition).

    CaffeineL-TheanineRhodiola Rosea