Blog
02
08
2018

Supplement in the Spotlight: L-Tyrosine

Tired of being tired?

Focused on being focused?

Unhappy with being unhappy?

In the first installment of this new series intended to put the spotlight on underappreciated supplements, I feature the supplement for you: L-tyrosine.

What It Is

L-Tyrosine (which I’ll refer to throughout the remainder of this article as simply “tyrosine”) is one of the few supplements which is just one of the 22 standard amino acids, alongside other frequently-discussed aminos like leucine. Indeed, tyrosine is present in significant concentrations in all high-quality protein sources: whey, casein, chicken, beef, fish, eggs, and other dairy products. As such, all of us consume tyrosine in one form or another every day.
Once ingested, tyrosine acts as the amino acid precursor to the L-dopa. In this context, when we speak of one compound acting as a precursor to another, we mean that it’s used to create the latter compound through a process of enzymatic conversion. For example, L-tryptophan, also one of the 22 standard amino acids, is the precursor to serotonin (the so-called “feel good” neurotransmitter), which is to say that enzymes convert tryptophan to serotonin in the brain.

Dopamine synthesis

L-Tyrosine (amino acid) –>  L-DOPA (amino acid) –> Dopamine (neurotransmitter)

What It Does

Subjectively, tyrosine can improve six distinct outcomes:

  • Mood
  • Ability to Feel Pleasure
  • Motivation / Drive
  • Focus / Sustained Attention
  • Energy
  • Sexual Arousal & Sensation

Note that there is, admittedly, some overlap between these outcomes. For example, one’s motivation (which I conceptualize roughly as the desire to do things) is highly related to one’s energy level, and sexual arousal and sexual sensation are related to the general ability to feel pleasure. However, I’ve done my best to cover all of the bases while still listing genuinely distinct effects, and I do think there are relevant differences between each of them.

How It Works

Recall that tyrosine is the precursor to L-dopa. Although L-dopa itself doesn’t cause the six aforementioned beneficial effects, it gets converted into something which does: dopamine.

Now, it’s important to understand that these six positive outcomes are not mediated exclusively by dopamine. Indeed, it’s my position – and this is hardly a controversial one! – that practically all neurochemistry-dependent physiological and psychological outcomes are affected by multiple neurotransmitters. For example, one can’t reasonably talk about depression without accounting for roles of serotonin and dopamine and norepinephrine. Nonetheless, given tyrosine is a precursor only to dopamine and not these other neurotransmitters, I do think it’s fair to say that the benefits which can result from tyrosine supplementation result from an increase in dopamine.

So, what exactly does dopamine do?

Well, I think it has at least three roles worth considering. First, dopamine levels seem to have a direct influence on mood and the ability to feel pleasure, with, to put it very simply, more dopamine meaning a better mood and more pleasure (to a point – overly high dopamine is actually implicated in the symptoms of schizophrenia and related psychiatric disorders). Second, dopamine, as a function of its being converted to norepinephrine, itself a neurotransmitter involved in skeletal muscle functionality, increases one’s subjective energy level (keep in mind “energy” has a different meaning in this lay context – ie how energetic you feel – versus a scientific context, in which it literally refers to energy itself). Third, dopamine levels, especially dopamine levels in a part of the brain called the prefrontal cortex, are heavily related to a family of cognitive functions called executive functions. These functions are of the utmost important in our lives, and include motivation, self-control (both the ability to force oneself to do something they don’t want to do and inhibitory control, ie gratification postponement), and mood regulation.

As such, I think tyrosine’s value as a supplement is clear: by temporarily elevating the production and release of dopamine, tyrosine supplementation can improve a wide range of physiological and psychological outcomes, ultimately making you feel better and, well, behave better – or, more technically, more in line with how you fundamentally desire to behave.

How to Take It

It is important to understand that simply ingesting the tyrosine naturally present in high-protein foods will not generate the effects one might desire from tyrosine supplementation. This is the result of the other amino acids present in food competing for transport into the brain at the blood-brain barrier. As such, it’s necessary to supplement with tyrosine in isolation, to create a substantial change in the ratio of tyrosine to other amino acids in your blood. Personally, I’ve used a wide range of tyrosine products, and quality has been subjectively equivalent between them; I merely recommend looking for pure L-tyrosine.

When to Take It

Because of the aforementioned competition at the blood-brain barrier, if you want to get the biggest dopamine bang for your tyrosine buck, you’ll want to dose tyrosine at least an hour away from protein-containing meals. However, this is not to say that tyrosine supplementation around meals is useless; it may simply be less effective on a per-gram basis.

How Much to Take

Interestingly, both the animal and human trials on tyrosine tend to use a very aggressive dosage: 100mg-150mg/kg, equivalent to 10-15g for a 100kg (200-pound) person. Now, it’s been my experience that such a dose is typically too stimulating, especially for the person new to tyrosine. As such, it’s my (admittedly experienced-based rather than study-based) suggestion to start at a dosage of 1-3g, ideally alongside caffeine at a dosage of 1g of tyrosine for every 100mg caffeine. If you find this dosage to be inadequate, only then experiment with higher dosages; I would recommend increasing by no more than 2g at a time, and using the research dosages as a cap.

author: Ian McCarthy

Ian is the Director of Online Coaching and Physique Programming at JPS and has years of experience in coaching and delivering some of the highest quality evidence based content in the fitness industry.