Tryptophan to tyrosine ratio

Tryptophan is the precursor to serotonin and then melatonin. Tyrosine is the precursor to dopamine and then noradrenaline. This ratio shows which of the two systems currently has more raw material.

In loose terms it is the balance between calm and drive. Neither end is better; what matters is whether the balance suits what you are asking of yourself.

On this panel the in-range band runs from 0.6 to 1.2, with 0.7 to 1.0 treated as optimal.

One caveat worth holding: circulating precursors are not the same as neurotransmitter production. Both conversions need cofactors, and tryptophan in particular can be diverted before it ever reaches the serotonin route.

Below 0.6 means tryptophan is low relative to tyrosine. Tryptophan is the rarest essential amino acid in food, so intake is one explanation.

The more common one is diversion. Inflammation and cortisol both activate the enzyme that sends tryptophan down the kynurenine pathway instead of the serotonin pathway, so a low ratio often reflects inflammatory load rather than diet.

That distinction matters, because if diversion is the driver then eating more tryptophan does less than reducing the inflammation causing it.

Between 0.7 and 1.0 the balance sits in the optimal band, with 0.6 to 1.2 reading as in range.

A varied protein intake across the day generally holds it there without any deliberate management.

Above 1.2 means tyrosine is low relative to tryptophan. Sustained stress is the usual cause, because it consumes tyrosine to make catecholamines faster than diet replaces it.

Supplementing tryptophan or 5-HTP without any tyrosine source pushes the ratio the same way.

Read it with your individual tryptophan and tyrosine results. A high ratio from low tyrosine is a different situation from a high ratio from high tryptophan, and they call for opposite corrections.

Chronic stress acts on both sides at once. It raises cortisol, which diverts tryptophan away from serotonin, and it drains tyrosine through sustained catecholamine production.

Low-grade inflammation from a Western dietary pattern compounds the diversion, which is the mechanism most often invoked to connect inflammatory load with low mood.

Balance the two: turkey, eggs, cheese and pumpkin seeds for tryptophan; almonds, avocados, chicken and fish for tyrosine.

Timing helps. Favour tryptophan sources in the evening when sleep and mood are the concern, and tyrosine sources in the morning when focus is.

Reducing inflammatory load addresses the diversion problem, which is often the larger constraint on this ratio than intake.

If tryptophan is the low side: 5-HTP at 100 to 200 mg in the evening, with vitamin B6 as P5P at around 25 mg as the required cofactor.

If tyrosine is the low side: N-acetyl L-tyrosine at 300 to 500 mg in the morning, with B6 and vitamin C.

Curcumin at around 500 mg daily is used to reduce inflammatory diversion. Raise any of these with your practitioner if you take medication affecting serotonin or dopamine.