L-Tyrosine Dosage: ~2 g (up to 100-150 mg/kg) Before the Stressor
Educational summary — not medical advice. See does it work for the MAOI, thyroid/levothyroxine, and levodopa cautions.
The honest answer
The studied dose is ~2 g at the low end, up to 100–150 mg/kg (often 7–13 g), taken as a single dose 30–120 minutes before an acute stressor — cold, sleep loss, heavy load — not daily. The catch: a 500 mg capsule is only ~¼ of the 2 g floor, so hitting a real dose from capsules means swallowing several at once. That's why plain powder — which scoops to 1–2 g — is the practical way to dose tyrosine.
The thing most people get wrong: it's a single dose, before, not daily
Tyrosine gives the brain extra raw material to make dopamine and noradrenaline while an acute stressor is depleting them. So the researched pattern is a single pre-load, taken 30–120 minutes before the cold exposure, the sleep-deprived shift, or the high-load task — not a daily capsule. In a rested person, tyrosine isn't the limiting factor in neurotransmitter synthesis, which is why the benefit is absent at baseline. Dose it to the event, not to the calendar.
| Question | Answer |
|---|---|
| How much? | ~2 g (low end) up to 100–150 mg/kg (~7–13 g for many adults) |
| When? | A single dose, 30–120 min before the stressor |
| Daily? | No — the benefit is stress-only; daily use isn't what the trials tested |
| A 500 mg capsule? | ~¼ of the 2 g floor — you'd need 4 just to reach the low end |
| Easiest way to hit the dose? | Plain powder — a scoop is 1–2 g at a fraction of the cost per gram |
| What about NALT? | Poorly converted — delivers less usable tyrosine per mg (why) |
Calculator: how many capsules is a studied dose?
Enter the L-tyrosine per capsule (from the Supplement Facts panel — usually 500, 750, or 1000 mg) to see how many capsules reach the 2 g floor. Add your body weight to also see the 100–150 mg/kg weight-based dose. This is the fastest way to see why powders win.
How to take it
- Target ~2–3 g for a general dose, or 100–150 mg/kg if you're matching the weight-based trials (Shurtleff 1994 used 150 mg/kg).
- Take it 30–120 minutes before the stressor, as a single dose — not on a daily schedule.
- Use plain powder to reach the dose cheaply. A 500 mg capsule is a quarter of the 2 g floor; a scoop of powder is 1–2 g — see the cost-per-gram ranking.
- Skip NALT for dosing. "N-acetyl-L-tyrosine" is poorly converted, so its milligrams don't map to usable tyrosine — details here.
The practical way to hit the dose
Because the studied dose is measured in grams, the honest recommendation is a plain tyrosine powder you can scoop to 1–2 g — the cheapest per gram in our set reaches the 2 g floor in about 2 servings. Full ranking on best value.
1000 mg per scoop — about 2 servings to reach the 2 g floor, at $0.05 per gram of tyrosine. A powder scoops to a real dose; a 500 mg capsule can't.
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Frequently asked questions
How much L-tyrosine should I take?
~2 g at the low end, up to 100–150 mg/kg (~7–13 g), as a single dose 30–120 min before the stressor. A 500 mg capsule is ~¼ of the 2 g floor, so powders are the practical way to dose.
When should I take it?
30–120 minutes before the stressor, not daily. Tyrosine helps while an acute stressor depletes dopamine/noradrenaline; at baseline it isn't the limiting factor, so daily dosing isn't what the research supports.
How many 500 mg capsules equal a studied dose?
Four to reach the 2 g floor. For a weight-based 100–150 mg/kg dose, a 70 kg person needs ~7–10.5 g = roughly 14–21 capsules — which is exactly why powders dominate.
Can I take it every day?
The evidence doesn't support daily use for cognition — the benefit is stress-only. Dose it situationally before a stressor, and avoid it (or clear it with your clinician) if you take an MAOI, have a thyroid condition, or take levodopa.
Related
- The dose gap & NALT — why the 500 mg capsule falls short and NALT is poorly converted
- Best value — every product ranked by cost per gram of tyrosine
- Does it work? — the stress-only evidence and the safety cautions
Sources
- Jongkees BJ, et al. "Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands — a review." J Psychiatr Res. 2015. PMID: 26424423 (doses ~2 g up to 100–150 mg/kg; taken before the stressor; benefit is depletion-dependent).
- Shurtleff D, et al. "Tyrosine reverses a cold-induced working memory deficit in humans." Pharmacol Biochem Behav. 1994. PMID: 8029265 (150 mg/kg dosed before cold exposure).
- Deijen JB, et al. "Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course." Brain Res Bull. 1999. PMID: 10230711 (~10 g/day under sustained stress; no mood effect).
- Full product dataset: /l-tyrosine/cost-by-brand.json (CC BY 4.0).