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L-Tyrosine

A dopamine precursor that shines under pressure — restoring mental performance when you're stressed or sleep-deprived.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsAmino acidsFocusStress

Tyrosine is the raw material for dopamine and noradrenaline. Its benefit is situational: it helps most when stress is depleting those transmitters.

Key takeaways

  • Tyrosine is the precursor to dopamine and noradrenaline.
  • It helps cognition under acute stress — cold, noise, sleep loss, heavy mental load.1
  • When you're rested and unstressed, it does little.
  • Typical dose ~2 g; safe for most.

What it is

L-tyrosine is a conditionally essential amino acid used to synthesise the catecholamine neurotransmitters that drive alertness and working memory.

The evidence

A review concluded tyrosine is “promising” as a cognitive enhancer, but only when healthy people are stressed or cognitively taxed — improving response inhibition, task-switching and working memory under demand.1

Dose & how to use

~2 g (studies range ~100–150 mg/kg) taken before a stressful or demanding task.

Safety & who benefits

Safe for most; interacts with certain psychiatric and thyroid conditions/medications — check first. Most useful for high-stress or sleep-deprived situations.

Bottom line: a situational nootropic — genuinely helpful under stress or sleep loss, unremarkable when you're well-rested.

References

Adult research summary for education, not a prescription. These are food supplements, not treatments for disease.

  1. Jongkees BJ, et al. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands—A review. J Psychiatr Res 2015. www.sciencedirect.com

This article summarises nutrition and exercise science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.