L-Tyrosine
CLimited / mixedHelps thinking under acute stress or sleep loss — but does little when you're rested and calm.
Grade C — Limited / mixed
What it does
Tyrosine is a precursor to dopamine and noradrenaline. Under demanding conditions (stress, cold, sleep deprivation) it can replenish neurotransmitters and protect working memory and cognitive flexibility. At baseline, rested, it does little.
How to take it
Commonly 100–150 mg/kg taken ~30–60 min before a demanding/stressful task. Situational, not daily.
Caveats & safety
Benefit is state-dependent — don't expect a day-to-day focus boost. Avoid with MAOIs or thyroid issues without medical advice.
The evidence
Jongkees BJ, et al. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands — a review. J Psychiatr Res.
2015 · Review of RCTs
Tyrosine improved cognitive performance specifically under demanding/stressful conditions; no benefit at rest.
Effect: Reliable working-memory/flexibility benefit under load; null when rested.
Read on PubMed →Should this be in your routine?
Ask the coach — it'll tailor doses to your sleep, goals and current stack.
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