Should you use L-tyrosine or N-acetyl L-tyrosine(NALT)? Tyrosine is an amino acid that has many important biological functions. It itís the precursor to thyroid hormone, as well as the catecholamines dopamine, epinephrine, and norepinephrine. NALT, which differs chemically by the addition of an acetyl group, in theory should be more bioavailable vs tyrosine.

However, the research shows otherwise. Most studies with NALT are intravenous studies, not oral but IV is 100% absorption so we can extrapolate. As far as raising tyrosine levels, a 5g NALT intravenous injection only increased levels by 25%. By contrast, an oral dose of 100mg can increase tyrosine levels by 140%. In fact, an oral dose of 100mg/kg of tyrosine increased tyrosine levels by up to 276%, which lasted 8hr. So why is that? Well, your body doesnít naturally produce or breakdown NALT. In fact, around 56% of all NALT is excreted intact(not converted to tyrosine/dopamine). Based on this, you should take L-tyrosine not NALT in order to get all the biological benefits.

For nootropic/focus purposes, a dose of 3g seems to have a strong affect for most users. There is 3g/serving of L-tyrosine in
#skywalk by @myoblox which has been my go-to nootropic formula to start my day.