howtosupplement
Cognition/Performance/Mood

L-Tyrosine

Amino acid precursor to dopamine and norepinephrine that may preserve focus during acute stress or sleep loss in healthy adults.

L-Tyrosine

L-Tyrosine

52
score
C
evidence
Caution
risk
Quick Take

Worth trying for occasional high-stress or sleep-deprived days; low value as a daily nootropic for most adults.

L-tyrosine is a nonessential amino acid found in protein-rich foods such as dairy, poultry, fish, soy, beans, and seeds. It is used to make dopamine, norepinephrine, epinephrine, and thyroid hormones; under acute stress or sleep loss, extra tyrosine may help maintain catecholamine production when demand rises. Human trials most consistently show modest benefits for working memory, alertness, and mental task performance in stressful conditions. Healthy adults facing short-term sleep loss, intense multitasking, or acute stress are the most likely to notice a benefit.

Proven Benefits

01
Working memory under stress
02
Alertness during sleep loss
03
May improve task-switching accuracy
04
May reduce mental fatigue
05
May blunt stress-related mood drop

Protocol

Amount
500-2000 mg
Frequency
Once, 30-60 minutes before the task or stressor
When
Best on an empty stomach or away from protein-heavy meals, which compete for transport.

Onset Time

Acute, usually within 30-60 minutes; most noticeable during stress or sleep loss

Who Should Consider

Shift workers facing occasional sleep loss
Students during exams or long study blocks
Professionals with high-stakes, stressful workdays
Adults doing demanding multitasking under pressure

Food Sources

  • Chicken breast (~1.2 g per 150 g cooked)
  • Firm tofu (~500 mg per 100 g)
  • Parmesan cheese (~450 mg per 30 g)
  • Pumpkin seeds (~400 mg per 30 g)
  • Eggs (~250 mg each)
  • Greek yogurt (~300 mg per 170 g serving)

How It Works

Tyrosine crosses the blood-brain barrier and serves as a precursor for catecholamines, especially dopamine and norepinephrine. During acute stress, cold exposure, or sleep deprivation, catecholamine synthesis can become substrate-limited; extra tyrosine may help preserve executive function and alertness in those settings.

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