Tyrosine (L-tyrosine)

Tier 2 — promising · Focus · Stress resilience · Cognition

A conditionally essential amino acid and direct precursor to dopamine, norepinephrine, and adrenaline. Military-funded RCTs (Neri 1995, Magill 2003) show L-tyrosine meaningfully preserves working memory and psychomotor performance during acute stressors including cold exposure, sleep deprivation, and demanding cognitive tasks. A 2015 rapid evidence assessment in Military Medicine reviewed 14 controlled trials and found a weak but consistent positive effect under acute stress conditions specifically. Critically, L-tyrosine does not enhance cognition in normal, rested, non-stressed…

Dose: 500-2,000 mg taken 30-60 minutes before an anticipated acute stressor or cognitively demanding task under time pressure. Lower end (500-1,000 mg) sufficient for most use cases.