L-Tyrosine
An amino acid precursor to dopamine, studied for focus under stress.
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What it is
L-tyrosine is an amino acid used to make dopamine, adrenaline, and thyroid hormone. The idea is that it can replenish these under demanding conditions.
How it works
L-tyrosine is an amino acid used to make dopamine, adrenaline, and thyroid hormone. The idea is that supplementing replenishes these under demanding conditions, supporting mental performance when the body is depleting them faster than usual.
What it's been studied for
Taken to support focus and mental performance, particularly under stress or sleep loss.
What the evidence shows
Some studies suggest tyrosine may help maintain cognitive performance during acute stressors like sleep deprivation or cold, but it doesn't appear to boost cognition under normal, rested conditions.
Who should consider it
It's used to support focus and mental performance, particularly under acute stress or sleep loss. It doesn't appear to help cognition under normal, rested conditions.
Amounts commonly studied
Studies use a wide range, often several grams before a demanding task.
How to take it
Studies use a wide range, often several grams before a demanding task. Plain L-tyrosine is favored over N-acetyl-L-tyrosine despite the latter's absorption marketing.
Forms & absorption
L-tyrosine or N-acetyl-L-tyrosine (marketed for absorption, though evidence favors plain L-tyrosine).
Food sources
High-protein foods — meat, fish, eggs, dairy, soy, and nuts.
Safety & interactions
Generally well tolerated. People with hyperthyroidism or on thyroid or MAOI medications should check with a provider, since tyrosine feeds thyroid and catecholamine pathways.
Myths & what it won't do
Myth: tyrosine is a daily nootropic that sharpens everyone's thinking. Reality: benefits appear mainly under acute stressors like sleep deprivation, not in rested people. Myth: it's a stimulant. Reality: it's a precursor, not a stimulant.
Common questions
- When does tyrosine actually help?
- Mainly under acute stress or sleep deprivation, where it may help maintain performance; it does little in rested, normal conditions.
- Plain or N-acetyl form?
- Evidence favors plain L-tyrosine; N-acetyl-L-tyrosine is marketed for absorption but less supported.
- Who should be cautious?
- People with hyperthyroidism or on thyroid or MAOI medications should check with a provider, since tyrosine feeds thyroid and catecholamine pathways.
The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.
Related goals
Research on L-Tyrosine
Recommendations on this page are informed by published research. This is educational information, not medical advice.
- Jongkees BJ, Hommel B, Kühn S, Colzato LS. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands — A review. J Psychiatr Res. 2015;70:50-57. View study →Note: Concluded tyrosine may help maintain cognitive performance under short-term stress or high demand, but is unlikely to help under normal, rested conditions.