L-Tyrosine 600 mg

Tyrosine was first isolated from casein in 1846, which is how it got its name — from the Greek tyros, cheese. The etymology is humble for a molecule that turns out to sit at the head of one of the body's more consequential pathways.

From tyrosine, the enzyme tyrosine hydroxylase produces L-DOPA; from L-DOPA come dopamine, then norepinephrine, then epinephrine. The same amino acid is also the backbone onto which iodine is fixed to build thyroid hormone, and the precursor of melanin. One substrate, three unrelated destinations.

L-Tyrosine supplies 600 mg per capsule. It is used to support normal catecholamine synthesis, healthy cognitive performance under demand, and normal thyroid function.

A note on limits, since it matters here: tyrosine is not a stimulant and does not act like one. Its role is to keep the raw material available when the pathway is running hard — during sustained mental work, low temperatures, sleep loss, or physical stress — conditions under which the body's own supply is drawn down faster than it is replaced. When the pathway is idling, extra substrate does little. It is best taken away from protein-containing meals, which compete for the same transporter.

Available in 100- and 250-capsule bottles.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.