Buyer’s Guide to Amino Acid Supplements

Buyer's guide to amino acids

There are hundreds of amino acids, but only a small handful are used by the human body. Of that small handful, only 9 are “essential”, meaning that they cannot be synthesized by the body from other substances and have to be taken in as part of the diet. There are 13 additional “non-essential” amino acids that are useful to the body, but not a necessary part of the diet as the body can create them from other substances. Collectively, these 22 amino acids that the human body uses are called the “standard amino acids”.

The Essential Amino Acids

The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Each plays a unique role, but collectively they are all needed to support all of the body’s basic physiological functions. Deficiency in even one of them can compromise your immune system, cause fatigue, and reduce muscle tissue as the body strips it for the amino acids it needs.

Essential amino acids are components of protein. If you’re eating protein, you’re taking in at least some of the essential amino acids. Not all protein sources have the same amino acid profile, however. When you see people talk about the “quality” of protein, what they’re primarily referring to is how much and how many of the essential amino acids it contains.

The Non-Essential Amino Acids

The 13 non-essential amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, ornithine, proline, selenocysteine, serine, and tyrosine. They’re hardly “non-essential” to the body, as they’re needed for all sorts of basic physiological processes just like the essential amino acids are. But if you’re eating enough protein and healthy carbohydrates, your body will have enough raw material to synthesize any non-essential aminos that it isn’t getting from your food.

Diet and When to Supplement

If you’re concerned about getting enough amino acids in your diet, you really only need to make sure you’re taking in an adequate amount of protein every day. If you regularly eat meat, fish, poultry, and eggs, or if you drink milk or eat cottage cheese, you likely don’t need to supplement with amino acids for nutritional purposes.

Aminos are a bit more of a challenge for vegetarians and vegans, however. Beans provide an amino acid profile that’s similar to that of meat, but unless you’re planning on eating beans and rice at every meal, you might run into some problems with deficiency. You can get smaller amounts of all of the essential aminos from various nuts and vegetables, but you’ll really have to keep an eye on what you’re eating and know the nutritional content of everything you’re taking in to ensure you’re not deficient. A powdered protein supplement may be appropriate, and they can be found in vegan and vegetarian alternatives such as hemp, soy, and pea.

Aminos for Bodybuilding – the BCAAs and Glutamine

There are three essential amino acids that are of special interest to bodybuilders and competitive athletes. These are isoleucine, leucine, and valine, collectively known as the branched-chain amino acids (or BCAAs).

While all of the essential amino acids are necessary to support muscle tissue, these three are specifically used in muscle function. They have thus become very popular as additives to various pre-workout and post-workout formulas. They’re widely *believed* to aid in muscle gains, mostly thanks to successful marketing by supplement manufacturers, but the actual science on them as relates to workouts is mixed. Studies in rats and sheep show consistent muscle gains, but there have been a number of human studies that have shown no effect when supplements were taken before, during and after workouts. This doesn’t necessarily mean that they don’t aid in gains, just that it can’t be said with 100% certainty that they do. Unfortunately, supplement advertising is largely unregulated, so they’ll go ahead and say it with 100% certainty anyway. The strongest scientific evidence as relates to bodybuilding is that intake of BCAAs puts the body in an anabolic state.

One situation where a bodybuilder can safely forego BCAA supplementation is when they’re bulking, as their increased dietary intake should be providing more BCAAs than the body can even put to use.

The only one of the non-essential aminos that bodybuilders might be interested in is glutamine. It’s frequently seen in training supplements advertised as a fuel source for muscles. As with the BCAAs however, while the claim is technically true, the science on whether supplementation with extra glutamine actually helps during workouts is unclear. Studies that have tested it on weightlifters have come up with no effects as of yet versus a placebo.

Amino Acid Supplement Quality

Unless you’re looking to supplement with just one or two specific amino acids, you’ll likely be taking an all-inclusive protein powder to get your aminos. Even if the supplement contains all nine of the essential amino acids, it may not actually contain as much protein as the label claims. Oftentimes these supplements are mixed with more inexpensive fillers such as taurine, creatine, glutamine, and maltodextrin. While each of these fillers can have their uses, they may not be what you’re looking for if you’re after pure protein content and amino acids. Even though these supplements aren’t well regulated, the label should still indicate if it contains substances other than protein.


A healthy and properly balanced diet will usually provide all the amino acids you need, but supplementation has its uses, particularly for vegans and vegetarians who don’t care all that much for beans. While there’s some solid scientific theory on BCAA supplementation increasing muscle gains and athletic performance, the actual test results in humans have been very mixed and a number of tests have shown no improvement whatosver versus a placebo. As with all types of supplements, be aware that FDA regulation is not very strong at present and what is advertised on the label may not entirely be true. Whole foods are always a safer and more nutritious alternative.


Related Articles By Cathe:

How Leucine Kickstarts Muscle Gains

2 Factors That Determine the Quality of a Protein

New Study Suggests More Protein is Better for Building Muscle

What’s the Best Type of Protein for Boosting Muscle Protein Synthesis?


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