Side Effects of Too Many Amino Acids

Amino acids are necessary for building your muscles and for the different neurotransmitters and hormones in your body.
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Amino acids are necessary for building your muscles and for the different neurotransmitters and hormones in your body. However, excess amino acids can be bad for you.


There are three types of amino acids: essential amino acids, nonessential amino acids and conditionally essential amino acids. The essential amino acids are the ones that you are most likely to take too much of when your levels are too high.

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Essential Amino Acids

According to the U.S. National Library of Medicine, there are 20 different amino acids that your body needs. However, only nine of them are officially considered essential. These nine essential amino acids are called histidine, leucine, isoleucine, methionine, lysine, threonine, phenylalanine, tryptophan and valine.

The reason that these nine amino acids are called essential is that they cannot be made naturally by your body. Instead, the only way you can get them is through your diet. Good sources of these amino acids are beef, poultry, eggs and fish. When you eat animal proteins such as these, they are broken down in your digestive system into amino acids, which are then assimilated into your body to assist with different processes.

Histidine: Per PubChem, histidine is the principal ingredient in the production of histamine, which is an important neurotransmitter. Histamine is necessary for the regulation of sleep cycles, sexual function, digestion and immune response. It is also critical to the proper functioning of your nerve cells.


Leucine: Leucine is a branched-chain amino acid or BCAA. Leucine is important for the repair of muscles and the synthesis of new protein, notes an October 2017 study published in Nutrition. It is important in the regulation of blood sugar levels, the healing of wounds and the production of growth hormones as well, says PubChem.

I-Isoleucine: I-Isoleucine is another BCAA that is important in the process of metabolism in muscles. It is found in muscles in large amounts. It is also important for the regulation of energy, the production of hemoglobin, and the functioning of the immune system, according to PubChem.


Methionine: PubChem points out that methionine is important to the process of metabolism and the detoxification of the body. It also aids in the absorption of selenium and zinc; two minerals that are crucial to your health. It is also part of the process of tissue growth.


Lysine: Lysine is necessary for the synthesis of proteins, enzymes and hormones and is also necessary for the absorption of calcium. It is important in a variety of other bodily functions, such as the production of elastin, collagen and energy, as well as the functioning of the immune system, per PubChem.


L-Threonine: L-Threonine is important in the synthesis of structural proteins, such as elastin and collagen, which are found in connective tissue, the skin and the hair. It is also important in the functioning of the immune system as well as the metabolism of fat, according to PubChem.

Phenylalanine: Phenylalanine is quite important in the makeup of neurotransmitters and is a precursor of many of them, such as epinephrine, norepinephrine, dopamine and tyrosine. It also plays a crucial role in the structural makeup and functioning of enzymes and proteins and helps in the production of other amino acids, says PubChem.


Valine: PubChem states that valine helps in muscle growth and muscle regeneration and is also an important part of the production of energy.

Tryptophan: Tryptophan is a precursor of serotonin, the neurotransmitter that regulates your sleep, mood and appetite, notes a January 2016 study published in Nutrients.

Read more: What Do Amino Acids Do for Your Body?


Possible Impact on Kidneys

Since the kidneys are so important in the regulation of the acid in the body, they are very susceptible to excess amino acids. Some amino acids may be naturally acidic while others will naturally be basic. The protein in your diet, however, will be acidic.

When you have a high-protein diet that results in high levels of amino acids in your body, your kidneys will have to work extra hard to keep the acid balance in the body at the proper level.



The body does not store extra amino acids, so if you consume too much, they will be broken down and eliminated, according to the Royal Society of Chemistry. The result is that you will have higher levels of urea and ammonia, and your kidneys will have to filter more blood.

Side Effects of Amino Acids

Arginine can cause gastrointestinal problems, such as abdominal pain, nausea, diarrhea and bloating, suggests the Mayo Clinic. Additional side effects of ingesting arginine supplements can be gout, inflammation of the airway and other allergic symptoms.

Arginine supplements can make the symptoms of asthma or allergies worse as well, so if you have either of these health conditions, use this supplement with caution. The Mayo Clinic recommends avoiding arginine for anyone who has had a heart attack. Anyone with cold sores or herpes should take it with caution as it can trigger the virus that causes these health conditions.

Your mood levels may be lower than normal with too much BCAA, which is noted in a small study of 59 healthy women ages 45 to 65 that was published in the January 2015 issue of the British Journal of Nutrition. Also, your sleep and wake cycles may be disrupted, according to a July 2015 review published in Evidence-Based Complementary and Alternative Medicine.

According to the Harvard T.H. Chan School of Public Health, proteins raise acidity levels in the body when they are digested, which generally leads to calcium being pulled from your bones (calcium is a base and gets pulled from the bones to neutralize the acidity caused by the proteins). This may lead to weaker bones, which can lead to more serious long-term effects.

Too many amino acids flooding into your body can do more harm than good, especially depending on your pre-existing conditions. You should, therefore, seek to have a balanced diet at all times and talk to your doctor before you take amino acid supplements.

Read more: Breaking Down Amino Acid Supplements: What to Know About EAAs and BCAAs




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