L-Tyrosine

Your intake

What each level of l-tyrosine does

Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.

1. Severely lowYOU ARE HERE

   0 mg – 330 mg

   Well below target. Risk of deficiency symptoms tied to dopamine precursor.

2. Insufficient

   330 mg – 1000 mg

   Below the recommended daily target. Long-term adequacy not assured.

3. Adequate

   1000 mg – 1500 mg

   Daily target met. Standard nutritional support for dopamine precursor.

4. Therapeutic

   1500 mg – 2000 mg

   Common for specific health goals. Check the evidence for your situation before sustaining this level.

5. Diminishing returns

   2000 mg – +

   Past the point where extra intake typically helps. Evidence for further benefit is thin.

Overview

Non-essential amino acid synthesised from phenylalanine; precursor to dopamine, norepinephrine, epinephrine, thyroid hormones, and melanin. Acutely studied for cognitive performance under stress (cold, sleep deprivation, multitasking) when catecholamine demand outpaces synthesis.

Functions

• ●Precursor to dopamine, norepinephrine, epinephrine (catecholamines)
• ●Precursor to T4 and T3 (thyroid hormones)
• ●Precursor to melanin (pigment)
• ●Phosphorylation substrate in signal transduction

Mechanism

Tyrosine hydroxylase (rate-limiting in catecholamine synthesis) converts tyrosine to L-DOPA, which decarboxylates to dopamine. Under acute stress (cold exposure, sleep loss, sustained vigilance), catecholamine release outpaces synthesis and tyrosine becomes the rate-limiting substrate. Acute supplementation supports continued performance; baseline-state supplementation in well-fed adults has minimal effect.

Benefits

• ●Improves cognitive performance under acute stress (cold, sleep deprivation, multitasking)
• ●Reduces blood pressure response to acute stress (military trials)
• ●May modestly improve working memory and inhibitory control
• ●Adjunctive in phenylketonuria management
• ●Not effective for routine mood, ADHD, or depression in adequate baseline status

Deficiency

Not a classical deficiency (synthesised from phenylalanine). Relative shortfall under acute high catecholamine demand or in PKU.

Excess

Well-tolerated up to ~12 g/day in trials. Doses above ~150 mg/kg may modestly raise blood pressure or cause headache.

Forms

• L-tyrosine free-form
  Standard form; affordable; well-absorbed empty-stomach
• N-acetyl-L-tyrosine (NALT)
  More water-soluble but less efficiently converted to plasma tyrosine; usually inferior
• L-tyrosine capsules
  Pill burden at 500–2,000 mg doses

Food sources

• Cooked chicken breast · 3 oz1 g
• Cooked beef · 3 oz1 g
• Cooked salmon · 3 oz0.8 g
• Pumpkin seeds · 1 oz0.4 g
• Almonds · 1 oz0.5 g
• Plain yogurt · 1 cup0.5 g

Supplement forms

L-tyrosine free-form at 500–2,000 mg, taken 30–60 minutes before a stressor on empty stomach. N-acetyl-L-tyrosine (NALT) is more water-soluble but less efficiently converted to plasma tyrosine — plain L-tyrosine is usually a better pick despite the marketing.

Bioavailability

~80% oral bioavailability; competes with other large neutral amino acids for the LAT transporter at the blood-brain barrier — high-protein meals blunt CNS uptake. Empty stomach + low-carb context produces the strongest cognitive effect.

Longevity relevance

Adequacy supports thyroid hormone synthesis and catecholamine function. Routine supplementation has no longevity signal in well-fed adults.

Relationships

References

• Examine — Tyrosinereview
• Jongkees — tyrosine and cognitive performance review (J Psychiatr Res 2015)review

About L-Tyrosine

Catecholamine precursor; cognitive resilience under stress. Common dose 500–2000 mg.

Role

Dopamine precursor

Daily target

1000 mg (TR)

Also called

l-tyrosine, tyrosine, n-acetyl-l-tyrosine, nalt