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The Ultimate Guide to Amino Acid Supplements

Your body's ability to function effectively requires the successful interaction between thousands upon thousands of different molecules -- and none are more important than amino acids.

Amino acids are a specific type of compound that play a myriad of different roles in your body. As such, if you are deficient in any one of them, then your ability to function can take a hit. Or worse, your health can even start to decline.

Beyond health, there is evidence demonstrating that supplementing with “above average” amounts of certain amino acids can offer additional benefits -- especially if for those who want to get the most out of their training.

What are Amino Acids?

Without going into too much unnecessary detail, amino acids are organic compounds made from nitrogen, carbon, hydrogen and oxygen.

They are often referred to as the building blocks of the human body, because they are used in the production of structural components, including bone, muscle, and connective tissue. They are also used to build your body's cells, as well as create enzymes, hormones, and neurotransmitters.

All of which means they have a direct impact on every facet of your health of function.

Now, it is important to note that your body needs 20 different amino acids to survive. And while I would argue that all of these are important in their own right, only nine of them are classified as essential.

The reason these nine are considered essential is because they cannot be made within the human body, and therefore must be obtained through the food that you eat. The essential amino acids are:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

As you might have guessed, the remaining 11 amino acids are known as non-essential amino acids because they can be made in your body using a variety of other compounds. The non-essential amino acids are:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamic acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

It is also important to note that during times of stress, illness, and recovery, some of these non-essential amino acids become “conditionally essential” because they are likely to be used at a faster rate than normal.

Those that can become conditionally essential are Arginine, Cysteine, Glutamine, Tyrosine, Glycine, Proline, and Serine.

The Best Amino Acid Supplements

Now, as I alluded to above, there is a base level of amino acids your body needs to survive. These are either made within your body, or in the case of essential amino acids, obtained from the food you eat.

However, there is evidence to suggest that supplementing with certain amino acids above this base level comes with additional benefits -- which is what we are going to talk about here.

1.   D-Aspartic Acid

D-Aspartic Acid (or DAA for short) is a variation of the amino acid “Aspartic Acid” that is found in small amounts throughout your body.

Although DAA plays several different roles in your body, it has its largest impact on your neuroendocrine system -- where it can enhance the production of neurotransmitters, growth factors, and hormones.

With this in mind, the supplementation of DAA has been shown to cause a significant increase in the secretion of testosterone [1], while also reducing the secretion of estrogen and cortisone [2], creating a better environment for muscle growth.

Additionally, DAA has also been shown to increase muscle strength and power immediately after supplementation [3]. This simply means you are able to put more weight on the bar or perform repetitions per set -- both of which are essential to increasing strength and size.

2.   Beta Alanine

Beta-alanine is the supplement form of the amino acid Alanine, which is found naturally occurring in your muscle tissue.

During exercise, alanine combines with another amino acid, “histidine” to form a unique compound called carnosine. During exercise, carnosine is used to buffer lactic acid, which staves off fatigue.

With this in mind, beta-alanine supplementation increases the carnosine content of your muscle tissue, improving your tolerance to fatigue. This has in turn been shown to cause large improvements in muscular and cardiovascular endurance [4].

While this may not sound that impressive, it can have a huge impact on the results of your training by allowing you to perform more to total reps per session -- which is integral to promoting muscle growth.

In fact, its supplementation has been shown to increase muscle growth and fat loss significantly more when combined with a solid resistance training program [5].

3.   Glutamine

Next up we have Glutamine,

This particular compound is actually the most abundant amino acid in the human body, where most of it is found inside your muscle tissue. Within your muscles, it helps promote the recovery and regeneration of muscle cells.

As such, supplementing with glutamine has been shown to accelerate recovery after heavy weight training. This has the ability to reduce muscle soreness, keeping your training sessions of a high quality at all times [6].

Moreover, glutamine is also used by your immune cells for energy. In this manner, its supplementation has demonstrated the capacity to improve immune system function, preventing disease and illness [7].

Although glutamine may not be directly responsible for increasing muscle growth, it is essential if you want to make long term progress.

4.   L-Tyrosine

We are now going to move away from those amino acids that focus on muscle tissue, and head towards the brain.

As its name so aptly suggests, L-Tyrosine is the supplement version of the amino acid Tyrosine. This important compound is used within your brain to produce two of our most important neurotransmitters, being dopamine and adrenaline.

It is for this reason that it appears in practically every pre-workout supplement on the planet.

Taking all of this into consideration, supplementing with L-tyrosine can enhance reaction time [8], boost attention, and even increase emotional wellbeing [9]. Amazingly, these effects have been shown to also contribute to improved exercise performance [10].

In our mind, this is the perfect supplement to boost your mental performance in the gym.

5.   L-Citrulline

Last but not least, we have L-Citrulline.

Now, you might have noticed that Citrulline does not appear on the list above -- but never fear, because there is a very good reason for this. L-Citrulline is actually the supplement version of Arginine. When you consume it, it enters the bloodstream and then moves into the liver. Once in the liver, it is quickly converted to Arginine.

Once converted to Arginine, it increases the production of nitric oxide throughout your entire body. Now this is important because nitric oxide is a vasodilator -- in which it increases blood flow to your muscles.

Via this mechanism, the supplementation of Citrulline has been shown to increase gym performance by improving the number of reps you can do each set, or even allowing you to add a couple of kilograms to the bar [11].

Similarly, evidence suggests that citrulline supplements can also slow the accumulation of fatigue during exercise [12]. This leads to higher quality sessions, which over time, could conceivably increase muscle growth.

Key Points

Amino acids are arguably the most important group of compounds found in your body. They play a role in practically every single one of your physiological processes, while also promoting the growth and development of nearly all your body's tissues.

As a result, supplementing with some of them can have some serious benefits, especially when it comes down to Aspartic Acid, Alanine, Glutamine, Tyrosine, and Arginine.

So, if you want to boost the result of your training, I would start with these guys -- just make sure you seek advice from a medical professional first (you know, just in case).



  1. Topo, Enza, et al. "The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats." Reproductive Biology and Endocrinology 7.1 (2009): 120.
  2. Falcone, Paul H., et al. "Consumption of a testosterone-boosting supplement is safe and lowers estrogen and cortisol levels." Medicine & Science in Sports & Exercise 47.5S (2015): 338.
  3. Melville, Geoffrey William. Effects of d-aspartic acid on testosterone and training outcomes in a resistance trained population: findings from an acute dosing study, and a three-month training study. Dissertation. Western Sydney University (Australia), 2016.
  4. Hobson, R. M., Saunders, B., Ball, G., Harris, R. C., & Sale, C. (2012). Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino acids, 43(1), 25-37.
  5. Kern, B. D., & Robinson, T. L. (2011). Effects of ?-alanine supplementation on performance and body composition in collegiate wrestlers and football players. The Journal of Strength & Conditioning Research, 25(7), 1804-1815.
  6. Legault, Zachary, Nicholas Bagnall, and Derek S. Kimmerly. "The influence of oral L-glutamine supplementation on muscle strength recovery and soreness following unilateral knee extension eccentric exercise." International journal of sport nutrition and exercise metabolism 25.5 (2015): 417-426.
  7. Cruzat, Vinicius, et al. "Glutamine: metabolism and immune function, supplementation and clinical translation." Nutrients 10.11 (2018): 1564.
  8. O'Brien, C., Mahoney, C., Tharion, W. J., Sils, I. V., & Castellani, J. W. (2007). Dietary tyrosine benefits cognitive and psychomotor performance during body cooling. Physiology & behavior, 90(2-3), 301-307.
  9. Banderet, L. E., & Lieberman, H. R. (1989). Treatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans. Brain research bulletin, 22(4), 759-762.
  10. Tumilty, L., Davison, G., Beckmann, M., & Thatcher, R. (2011). Oral tyrosine supplementation improves exercise capacity in the heat. European journal of applied physiology, 111(12), 2941-2950.
  11. Gonzalez, A. M., & Trexler, E. T. (2020). Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. The Journal of Strength & Conditioning Research, 34(5), 1480-1495.
  12. Pérez-Guisado, J., & Jakeman, P. M. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. The Journal of Strength & Conditioning Research, 24(5), 1215-1222.
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