N-Acetyl L-Tyrosine vs L-Tyrosine: Is one REALLY better?
Tyrosine is in just about every nootropic on the market right now. There's a very good reason for that - IT WORKS!
But we're seeing more and more talk online about the type of Tyrosine you need to take. Specifically, a lot of supplement companies are claiming that you need to take N-Acetyl-L-Tyrosine instead of L-Tyrosine because it is much more bioavailable.
Is this true?
Comparing L-Tyrosine vs N-Acetyl-L-Tyrosine, who wins?
In this article, we'll compare L-Tyrosine with N-Acetyl-L-Tyrosine to see if there is a difference and whether it really matters which on you take for cognitive enhancement.
What is L-Tyrosine?
Tyrosine is a non-essential amino acid frequently used in nootropic supplements because it is known to have benficial effects on cognitive performance.
Tyrosine is actually quite a common amino acid. It is found in a lot of widely-eaten foods, including soy products, chicken, turkey, fish, peanuts, cheese, yogurt, pumpkin seeds and more. When we talk about Tyrosine, we are almost always talking about L-Tyrosine, which is the most common isomer of the amino acid.
While people generally consume a lot of Tyrosine, the amounts obtained from food do not usually have a measurable effect on cognitive function. To really see major improvements in cognitive performance, you need to be taking Tyrosine supplements.
Many dietary supplements today contain L-Tyrosine. The amino acid is increasingly being sold as a supplement for a range of health conditions and purposes. As well as cognitive enhancement, L-Tyrosine is also touted for lowering acute stress, promoting mental health, and lowering blood pressure.
However, most people looking to use Tyrosine as a supplement do so for the effect it has on brain performance.
How do Tyrosine supplements work?
L-Tyrosine supplements (including those that use N-Acetyl-L-Tyrosine) work primarily by raising dopamine levels in the brain.
The neurotransmitters dopamine, serotonin and acetylcholine are responsible for a very big proportion of your cognitive processes. Raising or lowering these neurotransmitter levels can have a dramatic effect on cognitive function.
Dopamine specifcially is largely responsible for motivating behavior.
In simple terms, dopamine is released when you achieve a goal, or rather in anticipation of achieving that goal. This elicits a pleasurable feeling, driving you to keep moving towards your goal.
Tyrosine supplements work by increasing dopamine levels in the brain. The amino acid L-Tyrosine is a fundamental building block of dopamine. When consumed, Tyrosine is turned first into L-DOPA and then into useable dopamine in the brain.
L-Tyrosine vs N-Acetyl L-Tyrosine Supplements: What's the difference?
So what is the difference between L-Tyrosine and N-Acetyl-L-Tyrosine?
In theory, the primary difference between N-Acetyl L-Tyrosine and L-Tyrosine is that N-acetyl l-tyrosine has greater bioavailability - and therefore stronger nootropic effects - than L-tyrosine.
But while NALT appears to be the better form of supplementary tyrosine due to its bioavailability and easy absorption, in practice there is very little difference between the two - other than cost!
Let's take a closer look at the benefits of both L-Tyrosine and N-Acetyl L-Tyrosine, the side effects, the differences in bioavailability, and the costs to see if there really is a big difference between N-Acetyl L-Tyrosine and L-Tyrosine.
L-Tyrosine has been found to have a number of nootropic benefits in several good quality clinical trials.
The main benefits of L-Tyrosine supplements observed in clinical studies revolve around improved task performance during times of acute stress.
People given L-Tyrosine (or N-Acetyl L-Tyrosine) supplements and exposed to stressful conditions such as cold stress, sleep deprivation, mild heat stress or stressful events or tasks all performed better at mental tasks than those given a placebo.
In the context of stressful situations, L-Tyrosine can be said to provide the following benefits:
- Improved memory function
- Faster reactions
- Sharper focus
- Increased motivation and drive
- Improved mood
All of this results from Tyrosine's effect on dopamine levels. Because having elevated dopamine keeps you motivated and in a positive mood, it helps you power through stressful situations without getting demotivated.
As well as motivational behavior, dopamine also plays a domainant role in general cognitive function. Having healthy dopamine availability in the brain will deliver broad cognitive enhancements including improved focus, faster processing speeds, reduced anxiety, quicker decision making, and improved mood.
L-Tyrosine and B6
It is vital that you take Vitamin B6 with L-Tyrosine or N-Acetyl L-Tyrosine in order to see real benefits. This is because B6 is a necessar cofactor in the conversion of Tyrosine into L-DOPA and finally into dopamine.
N-Acetyl L-Tyrosine Benefits
So what are the benefits of taking N-Acetyl L-Tyrosine? How are the benefits of N-Acetyl L-Tyrosine different to the benefits of L-Tyrosine?
The fact of the matter is, there is no practical difference between the benefits of N-Acetyl L-Tyrosine or L-Tyrosine. There are no extra benefits associated with the use of N-Acetyl L-Tyrosine that are not also linked with L-Tyrosine.
All of the good quality clinical studies looking at the effects of Tyrosine supplements have used either N-Acetyl L-Tyrosine or L-Tyrosine. There is no significant difference between the benefits reported by these studies. In other words, the benefits of N-Acetyl L-Tyrosine are the same as the benefits of all Tyrosine supplements.
NALT vs Tyrosine: Absorption and Bioavailability
The only discernible difference between N-Acetyl L-Tyrosine and L-Tyrosine is the bioavailability and absorption rate.
NALT is the acetylated form of Tyrosine. Because of its structure (with the added acetyl group), N-Acetyl L-Tyrosine is more readily absorbed by the human gut than simple L-Tyrosine. This is because NALT is more soluble than Tyrosine, so it is more readily carried by water molecules.
However, this is all just theory!
If you look at the data, there is no real evidence proving that N-Acetyl L-Tyrosine is meaningfully more bioavailable or dramatically better absorbed than L-Tyrosine.
The added acetyl group will increase the bioavailability of N-Acetyl-L-Tyrosine, but this does not typically translate to significantly better results, and studies indicate it does not actually lead to drastically higher plasma Tyrosine levels when using similar doses. Therefore, paying signficiantly more for N-Acetyl-L-Tyrosine may not be worth it.
An intravenous infusion of L-Tyrosine is likely the only way to genuinely increase plasma Tyrosine levels significantly more than you can with oral Tyrosine supplements. L-DOPA is normally administered using intraveous injections for the treatment of Parkinson's Disease.
Tyrosine vs NALT: Side Effects
Is there a difference in the side effects when you compare N-Acetyl-L-Tyrosine and L-Tyrosine?
The answer is no, there is no difference between L-Tyrosine and N-Acetyl-L-Tyrosine when it comes to side effects.
Both L-Tyrosine and N-Acetyl-L-Tyrosine are known to be virtually side effect-free when taken in sensible doses. Studies do not typically report any drop outs from negative effects.
Very rarely, people may experience some side effects when taking L-Tyrosine or NALT. This usually happens when taking larger doses. These side effects can include:
- Increased diastolic blood pressure
- Elevated heart rate
- Abnormal activation of neurotransmitter receptors
- Making you more susceptible to lethal heat stress
Because both of these Tyrosine supplement forms work by raising catecholamine neurotransmitter levels (those monoamine neurotransmitters made in the adrenal glands), they may negatively interact with certain medications or health conditions.
It is vital that you consult with your doctor before using either N-Acetyl L-Tyrosine or L-Tyrosine supplements, especially if you have a health condition or are taking medication that affects neurotransmitter levels (e.g. antidepressants).
NALT vs Tyrosine: Cost
This is really the only real, practical difference you'll find on this L-Tyrosine vs N-Acetyl-L-Tyrosine page: the price.
N-Acetyl L-Tyrosine is significantly more expensive than L-Tyrosine. This is probably obvious to you given that L-Tyrosine is a naturally abundant amino acid while NALT is an augmented form of L-Tyrosine. NALT is much harder to make, which is why it is so expesnive.
You can see this reflected in the prices of certain nootropic stacks. Those pre-made nootropics, energy supplements or caffeine pills which use NALT instead of L-Tyrosine are almost always much more expensive.
But you get what you pay for, right?
In terms of delivering cognitive enhancement, helping you stay focused through a stressful event, or just supporting healthy levels of dopamine throughout the day, NALT does not offer any benefits over and above simple L-Tyrosine supplements.
Studies have variously used both N-Acetyl-L-Tyrosine and L-Tyrosine and there has been no significant difference in the benefits observed between the two Tyrosine forms.
This raises the question of why you would pay more for NALT when you aren't getting any extra benefits than you would get from taking the - much cheaper - L-Tyrosine form?
Should you use N-Acetyl-L-Tyrosine or L-Tyrosine Supplements for Mental Performance?
For overall cognitive enhancement, L-Tyrosine supplements are a fantastic choice. Any good nootropic stack, caffeine pill or neurostimulant should contain some Tyrosine.
Tyrosine is highly effective for improving task performance, especially in individuals subjected to cold stress, sleep deprivation, and potentially for those suffering with mild cognitive decline caused by chronic stress. This makes it perfect for students, athletes, over-worked developers, sleep deprived traders, and people with stressful jobs.
But should you take L-Tyrosine or N-Acetyl-L-Tyrosine?
Which is the better supplement?
There is no observable difference between L-Tyrosine and N-Acetyl-L-Tyrosine when it comes to raising dopamine levels.
We know from practical experience that NALT doesn't give you any benefits that you don't get from L-Tyrosine.
The only difference between these two forms of Tyrosine is that NALT is much more expensive. So save yourself some money and use a nootropic stack which combines a good serving of L-Tyrosine with other potent cognitive enhancers.
- Cognitive flexibility
- Neurotransmitters dopamine
- Plasma Tyrosine levels
- Dietary supplements
- Amino acid precursors
- Cold stress
- Mild heat stress
- Diastolic blood pressure
- Utilization of tyrosine dipeptides
- Stop-signal task
- mitochondrial function
- activation of FoxO