Lifesource Vitamins L-Tyrosine — 500 mg, 120 Capsules — Supports Mental Alertness & Cognitive Performance Under Stress*
Lifesource Vitamins L-Tyrosine is a conditionally essential amino acid and precursor to catecholamines (dopamine & norepinephrine) to support mental alertness, focus, and stress resilience. Non-GMO; crafted in FDA-registered, GMP-certified facilities and 3rd-party lab tested for identity, potency & purity.*
Research-Driven & Verified Product.
Explore the clinical research, ingredient science, and global evidence supporting this product below.
Research Promise — At Lifesource Vitamins, our commitment is rooted in research and results. Every benefit below is supported by human clinical studies indexed in the National Institutes of Health (NIH) via PubMed, with full texts available in the National Library of Medicine (NLM) PubMed Central (PMC) when available. In addition, we reference reviews from leading health organizations and insights from top global universities to ensure our guidance aligns with credible science.*
Clinically Studied Benefits
✓ Supports cognitive performance during demanding training — maintained task performance in military cadets during intensive field training.* NIH/PubMed — Deijen, 1999
✓ Helps preserve working memory under cold stress — in healthy adults exposed to cold conditions.* NIH/PubMed — Shurtleff, 1994
✓ Reduces vigilance lapses and psychomotor decline — with sleep deprivation.* NIH/PubMed — Neri, 1995
✓ Alleviates cold-induced working-memory decrements — during repeated immersions.* NIH/PubMed — Mahoney, 2007
✓ Supports psychomotor accuracy and cognition — during cold exposure (e.g., marksmanship tasks).* NIH/PubMed — O’Brien, 2007
✓ Helps maintain performance under psychological stressors — (e.g., loud noise) on stress-sensitive tasks.* NIH/PubMed — Deijen, 1994
✓ Short-term tyrosine loading benefits cognition — when tasks are demanding or stress is high (systematic review).* NIH/PubMed — Hase, 2015
✓ Mitigates stress-related performance decrements — in healthy adults/military settings (rapid evidence assessment).* NIH/PubMed — Attipoe, 2015
✓ Benefits most apparent under high demand — when dopamine/norepinephrine demand is elevated (meta-analytic/qualitative review).* NIH/PubMed — Jongkees, 2015
✓ Modulates task control & response inhibition — fronto-striatal signals observed after tyrosine (mechanistic/acute).* NIH/PMC — Bloemendaal, 2018
Additional / Promising Evidence
✓ Catecholamine precursor in human stress models — overview in stress and cognition contexts.* NIH/NLM — NASEM, 1999
✓ Evidence is context-dependent — benefits most likely under acute stress; null in some heat-exercise trials.* NIH/PubMed — Coull, 2016
✓ Performance preservation in cold+hypoxia model — early double-blind crossover showed benefits vs placebo.* NIH/PubMed — Banderet, 1989
✓ Supports focus under environmental stressors — preliminary data in various acute challenge models.*
✓ Precursor role in neurotransmitter synthesis — supports dopamine/norepinephrine pathways during demand.*
✓ Potential in high-demand cognitive tasks — emerging evidence for resilience in stressful scenarios.*
University-Led & Academic Studies
✓ Vrije Universiteit Amsterdam — psychological stress tasks — tyrosine aided performance under stress.* NIH/PubMed — Deijen, 1994
✓ US Army Research (USARIEM) — vigilance/psychomotor function — preserved during sleep loss and environmental stressors.* NIH/PubMed — Neri, 1995
✓ USARIEM — cold exposure psychomotor accuracy — supported cognition and performance.* NIH/PubMed — O’Brien, 2007
Global Evidence & Reviews
✓ NIH/NLM — National Academies (NASEM) Review — summarizes human tyrosine findings in stress and cognition.* NIH/NLM — NASEM, 1999
✓ Systematic reviews on tyrosine and cognition under stress — benefits in demanding or stressful contexts.* NIH/PubMed — Hase, 2015
✓ Meta-analytic/qualitative review — effects most pronounced when catecholamine demand is high.* NIH/PubMed — Jongkees, 2015
We monitor research from leading institutions —
Harvard, Johns Hopkins, Mayo Clinic, Cleveland Clinic, Cambridge, Oxford, Stanford, Yale, Tufts, University of Florida, Oregon State University – Linus Pauling Institute, Columbia, Cornell, Ohio State — to align with credible science.*
Key Ingredients
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L-Tyrosine — conditionally essential amino acid and precursor to dopamine & norepinephrine for mental alertness and stress resilience.*
Brief Benefit Bullets
- Helps you stay mentally alert during stressful, cognitively demanding moments*
- Supports working memory, focus, and task accuracy under environmental stressors like cold or sleep loss*
- Precursor to key neurotransmitters (dopamine & norepinephrine) linked to attention and stress response*
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3rd-party lab tested for identity, potency & purity
Suggested Use
See product label for full instructions, or as directed by your healthcare professional. Do not exceed recommended dose. If pregnant, nursing, taking medications, or have a medical condition, consult your physician.*
Product Specifications
- Serving Size — See Supplement Facts label
- Servings Per Container — See Supplement Facts label
- Form — Easy-to-swallow vegetarian capsules
- Free From — Non-GMO, gluten-free, no artificial colors, preservatives or synthetic chemicals*
- Quality — Third-party tested for identity, potency & purity
LifeSource Vitamins — Proudly American — Since 1992
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Lifesource Vitamins L-Tyrosine — 500 mg, 120 Capsules — Supports Mental Alertness & Cognitive Performance Under Stress* Clinically Studied Ingredients — NIH/PubMed!*
