N-Acetyl-Tyrosine
Useful mainly for cognitive or stress performance applications where free L-tyrosine is unavailable or less preferred.
Quick decision guide
May help most
Cognitive or stress performance applications where free L-tyrosine is unavailable or less preferred
Common dosing range
300–600 mg/day (supplement labels); free L-tyrosine is more bioavailable for most uses
When to expect effects
Hours (acute cognitive/stress effect if any)
Watch out for
MAO inhibitors — combination risks hypertensive crisis; NALT has lower bioavailability than free L-tyrosine
What is it
N-acetyl-L-tyrosine (NALT, also written N-acetyltyrosine) is an acetylated derivative of the proteinogenic amino acid L-tyrosine, marketed in cognitive and pre-workout supplements on the assumption that the N-acetyl group improves water solubility and stability compared with free tyrosine. After absorption it is hydrolyzed in the kidney by acylase to release free tyrosine and acetate; in humans, however, plasma tyrosine rises only modestly because a substantial fraction of NALT is excreted unchanged in urine, particularly at supplemental oral doses. Tyrosine itself is the substrate for tyrosine hydroxylase, the rate-limiting enzyme in catecholamine (dopamine, norepinephrine, epinephrine) biosynthesis, and is also a precursor to thyroid hormones and melanin.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
cognitive performance under acute stress (tyrosine precursor) Limited Evidence | Modest; primary evidence is from free L-tyrosine trials, not NALT specifically | Adults facing acute cognitive demand under stressors (sleep deprivation, cold, multitasking) | Hours |
tyrosine source for parenteral nutrition Limited Evidence | Reliably raises plasma tyrosine in IV/enteral settings where free tyrosine is insoluble | Patients requiring parenteral or enteral nutrition where tyrosine solubility is limiting | Hours |
cognitive performance under acute stress (tyrosine precursor)
- Effect
- Modest; primary evidence is from free L-tyrosine trials, not NALT specifically
- Best fit
- Adults facing acute cognitive demand under stressors (sleep deprivation, cold, multitasking)
- Time
- Hours
tyrosine source for parenteral nutrition
- Effect
- Reliably raises plasma tyrosine in IV/enteral settings where free tyrosine is insoluble
- Best fit
- Patients requiring parenteral or enteral nutrition where tyrosine solubility is limiting
- Time
- Hours
Evidence for 2 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
cognitive performance under acute stress (tyrosine precursor)
Supplement benefitFree L-tyrosine has moderate RCT evidence showing attenuation of cognitive decline under acute stressors (cold, sleep deprivation). NALT is marketed as a more water-soluble form but is substantially excreted unchanged in urine rather than converted to tyrosine; plasma tyrosine rises only modestly. Direct NALT trials are scarce. Extrapolating evidence from free tyrosine to NALT involves uncertainty.
Bottom line: The stress-cognition evidence base belongs to free L-tyrosine; NALT's inferior bioavailability limits confidence that it provides equivalent benefit.
Evidence is mixed
Positive cognitive evidence in stress contexts comes from free L-tyrosine studies, not NALT; form-specific conversion data suggest NALT may be less effective per gram.
tyrosine source for parenteral nutrition
Corrects deficiencyNALT was developed for parenteral nutrition because tyrosine has limited aqueous solubility at physiological concentrations. In clinical IV settings, NALT is hydrolyzed by kidney acylase and raises plasma tyrosine effectively. This is a specific medical use case, not a general supplement benefit.
Bottom line: Established utility in clinical parenteral nutrition; not directly translatable to oral supplement benefit.
How to take it
What to track
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Hypertensive crisis when combined with MAO inhibitors (phenelzine, tranylcypromine, isocarboxazid, linezolid, selegiline)
Who should avoid it
- People taking any MAO inhibitor
- People with hyperthyroidism or Graves' disease (tyrosine is a thyroid hormone precursor)
- People with tyrosinemia or other inborn errors of tyrosine metabolism
- Melanoma patients (theoretical concern — melanin precursor)
Pregnancy & breastfeeding
Insufficient data for supplemental NALT doses in pregnancy; avoid unless directed by physician.
Interactions
MAO inhibitors impair catecholamine degradation; excess tyrosine-derived catecholamines can cause hypertensive crisis
Tyrosine is a thyroid hormone precursor; theoretical interaction; monitor thyroid function
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
References by claim
Track N-Acetyl-Tyrosine with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.