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L-Arginine Overview - Benefits, Side Effects, Dosage

L-Arginine Overview - Benefits, Side Effects, Dosage

L-Arginine is an amino acid, which are often referred to as the “building blocks” of proteins. It is obtained through our diets, in the form of animal sources, and other protein-rich foods, which include beef/red meats, fish, dairy, eggs, and poultry, among other foods. L-arginine occurs naturally in “complete proteins” which supply our bodies the amino acids they require, but the substance is also created in a lab-setting, meaning it can be purchased in the supplement form. This not only promotes the heart health benefits L-arginine provides, but can help enhance mental capabilities, improve exercise performance, increase energy levels, and much more.

How does it work?

Although it isn’t an “essential” amino acid (one which our body can’t produce on its own), it is still considered ‘somewhat’ essential, because it is highly important in helping our bodies perform many functions it couldn’t perform, without this amino acid complex. Further, it is present in lower levels in our body, especially as we age, meaning a supplement or other source to help increase levels of l-arginine, is usually necessary as individuals get older. One of l-arginine’s major benefits is the ability to increase blood flow and rate of circulation in our system. As it is converted into a form of nitric acid in our bodies, it helps the blood vessels open, meaning blood flow is faster, which improves circulation naturally.

Of course, many benefits will instantly present themselves because of this. Improvement in overall immune functions and capabilities, detoxification, fertility levels will increase, and it even has a positive impact on brain power and cognitive abilities. L-arginine is also important in that it helps in the production of certain hormones, especially growth hormones and insulin, which help with pushing glucose into the cells, which will in turn be used for growth and increased energy output. Because of these benefits, l-arginine is typically linked to improvements in physical performance, stamina, greater levels of strength, and energy levels. All positive byproducts of using this supplement form.

What else can it do for you?

In addition to the above-named benefits, incorporating an l-arginine supplement into your diet can also be beneficial in other ways as well. Among these are:

-          Fighting inflammation in your body.

-          Helping to lower the risk for arteriosclerosis, heart attack, and other heart conditions.

-          Improved blood flow and repairing blood vessels which are damaged.

-          Helps to fight CHF (congestive heart failure, as well as coronary artery disease.

-          It can help reduce high blood pressure levels.

-          It can improve immune function, help reduce muscle pains and aches (especially in the legs caused by blocked arteries), and it can help improve overall athletic performance and energy levels.

Improvements in mental clarity and capacity, greater kidney function (filtering), helping to fight dementia, and correcting impotence (ED) and male infertility, are other known benefits of using l-arginine as a dietary supplement. It is also linked to helping prevent the common cold, so you aren’t going to get as sick, as often, during cold and flu season.

So, you’re already interested in the supplement. But, to fully understand what it can do for you, it is important to understand how nitric oxide (NO) is going to work in your body, so you have a better understanding of what the supplement will do. Nitric oxide is a natural reactive gas (in plants and animal produce). The l-arginine amino acid creates this natural gas, and it is a byproduct which forms from different chemical reactions which occur.

L-arginine is necessary by the endothelial cells (lining the blood vessel), for the nitric oxide to keep proper blood flow in the system. NO is known to help improve blood circulation, as it naturally dilates the blood vessels. NO helps keep blood pressure levels at bay as well, which naturally signals your blood vessels to relax, and helps expand them, which further allows for free blood flow and increased circulation levels. This can help prevent clotting, and it can also help prevent plaque from forming in the arteries.

Research on this topic has suggested that as individuals age, their ability to produce NO in arterial-linings, decreases. The simple solution to the problem? Incorporating an l-arginine supplement which will naturally help to enhance NO capabilities and will help correct the impaired endothelial function in the system over time as well. The ability to produce NO is exceptional; with this being said, L-arginine is going to offer more benefits than this to its users. It has many important roles in nerve signaling, it helps with cell replication functionality, it helps to fight oxidative stress, which in turn helps to reduce the signs of aging as you get older.

The 5-benefits of L-arginine

1. It will improve overall heart health –

L-arginine has been researched extensively, and this research shows it is beneficial in lowering levels of inflammation, as well as helping to improve the health of blood vessels. It is also important for the cardiovascular system, which is one of the main reasons cardiologists suggest a supplement, even to those who are healthy/younger in age. If you are at a high-risk level for coronary heart disease, incorporating an L-arginine supplement is extremely effective in helping to prevent the possibility of a heart attack.

How does it improve cardiovascular health? L-arginine helps to prevent high blood pressure levels, it helps increase blood flow through the vessels, and for those with clogged arteries, it can help open the vessels to improve blood flow. It is known to help reduce cholesterol levels, it can help relieve congestive heart failure, and it can improve stamina levels. Many find it helps reduce the symptoms which are linked to cut-off blood flow from the heart to the limbs as well.

L-arginine has been commonly used in treating angina attacks and chest pain, namely because of the effects of NO on the body, which help prevent blood clots and cut off blood supply. Simply taking 2-3 grams daily has been shown to help resolve nitrate intolerance in most people who suffer from angina. It is also known to help safely improve exercise performance, in those with low stamina levels, or circulation problems.

2. Lower inflammation levels & fight effects of aging –

Fighting disease-causing inflammation and raising immune function, are two of the most prominent uses for L-arginine apart from optimal heart health which the supplement promotes. It can help raise immune function as well. Having a substantial free radical-scavenging capability, the supplement will naturally target the signs of oxidative stress, and has a natural effect on the superoxide dismutase (SOD) enzyme, and other antioxidant benefits in your system.

The supplement is typically taken in conjunction with other antioxidants, and vitamins C as well as omega-fish supplements, to help slow down the signs of aging. It has also been linked to helping prevent certain chronic diseases in many individuals.

The central and nervous system are both positively impacted by l-arginine supplements as well, as is immune system function. This is because NO acts in the brain as a neurotransmitter, and a protective agent against the outside threats which present themselves. It is helpful in detoxifying the body as well. If you want to lower the presence of ammonia in the blood, l-arginine has been used in treating metabolic problems of this nature, and damage to the urethra, where ammonia is excreted from the body. Ammonia can lead to cell destruction and inflammation, both which l-arginine is known to combat, and help reduce over time.

3. Improves exercise performance –

If you exercise but are always tired, or don’t exercise and would like to begin a healthier lifestyle, l-arginine is known to effectively improve blood flow; this in turn means it can help bring the nutrients and oxygen to the body, muscles, and to joint tissue. This means it is naturally going to benefit you, give you more stamina, and ensure when you do exercise, you are going to experience fewer aches and pains afterwards.

It is used in some cases to help increase heat and circulation to damaged joints, or to help with cold hands and feet, in individuals who suffer from health conditions, which are linked to poor blood flow in the body. Additionally, those who suffer from arthritis and diabetes can benefit from incorporating the supplement into their daily regime. If you suffer from painful intermittent claudication (narrow blood vessels), the supplement has been proven to help improve walking distances, and reduce the levels of muscle aches and pains in these individuals.

L-arginine is used by the body to help increase production of hgh (human growth hormone). It also helps increase levels of prolactin and other amino acids (including creatine, l-glutamate and l-proline). If you are sensitive to insulin, it can also help reduce sensitivities, similarly to the manner in which exercise does, as it allows higher glucose levels to enter the cells.

The role l-arginine plays in metabolic health is also important as it helps to build strong muscle tissue, it helps fight inflammation (which causes bone and joint pain), it can help with the repair process after an injury, and it can help improve general nervous system function as well.

Growth hormone levels have been proven to increase in numerous studies as well, with the use of an l-arginine supplement. This is when taken in dosage levels from 5-9 grams daily. In many cases, it increases the restring growth hormone levels at least 100%, and can increase levels by up to 500% daily in some instances.

Even more powerful is when you combine l-arginine with daily exercise. Evidence suggests that supplementation increases plasma insulin in the body and helps to build stronger, leaner muscles. This is true even when you are resting. Your metabolism is also positively impacted by the hormonal changes, as they help to repair, build, and to maintain the youthful foundation of the skeletal muscle system.

4. Immune system improvement, prevention/speedy recovery of healing –

Low-circulating supplementation has been known to help some patients who suffer from illnesses, trauma, and different forms of cancer. It’s believed that some of the immune system suppressor cells (MSCs) may cause deficiencies in arginine, or low levels of circulation within the blood. This is a problem because immune system is meant to protect lymphocytes and t-cells, which depend on arginine to defend your body.

Used alongside omega-3 fish oils, the arginine supplement, and other supplements, can help reduce risk for infections, especially the respiratory kind, or those which deal with the lungs/breathing. It can also help to lessen the healing time after an injury, and it can help to shorten recovery time following cancer treatments. If you suffer from illness or have a surgery, it has also been known to help reduce those recovery processes and speeds as well.

Sometimes it is added to topical ointments which are used in treating wounds. By helping to keep blood flowing more freely, it can also help fight the pain from swelling. It forms l-proline, which is also important in collagen synthesis, and can help increase antioxidant level activity in the body naturally.

Protein function improvement is yet another benefit of l-arginine supplements. It can help to heal burns faster, and it can help fight cavities/tooth decay as well. It also has positive immune-enhancing effects, so it has been given to those who are undergoing chemo treatments or therapies, or healing from surgery, and viruses including HIV.

5. Treating ED/infertility –

Studies which use l-arginine supplements have found that it is involved in the process of cell replication, as well as enhancing blood circulation, both which can improve sperm production and motility. Men who have cardiovascular problems which are tied to low levels (or no) NO often suffer from ED and fertility issues. Although it isn’t effective for every man, many males suffering from infertility (some studies indicate up to 92%) have seen improvements when l-arginine supplements were combined with other dilators, anti-inflammatories, and other antioxidant supplements.

Research also suggests that high stress levels can be lowered when l-arginine is present in the sperm production pathway. If men are overly stressed, they can also benefit from the supplement. When combined with l-glutamate and yohimbine hydrochloride, it is a highly effective method of treating ED, and is often said to be better than use of l-arginine alone.

Some women can even experience higher reproductive capabilities when incorporating an l-arginine supplement into their diet. Doctors prescribe topical creams which contain this amino acid, to help heal sexual problems, and as a natural infertility treatment. Some research also suggests that treatment with n-acetyl (NAC) can help naturally balance hormonal levels. This can help restore normal sexual function in women with polycystic ovary syndrome, as well as those who suffer from estrogen imbalances.

Other studies also suggest that incorporating l-arginine with herbs and teas, alongside antioxidant supplements, can help to serve naturally improve pregnancy rates in women who are struggling to conceive.

How much is enough?

Each person produces some level of l-arginine naturally, but the levels will vary. Your age, diet, inflammation levels, quality of life, condition of heart/arteries, gender, genetics, and other factors, will cause these levels to differ. If you are on a vegan/vegetarian diet, this can also contribute to lower levels of l-arginine being produced in your body naturally. If you have poor digestive health or have a hard time metabolizing protein, this can also reduce those levels naturally. Those who suffer from stress, and have high oxidative stress levels, are also going to produce less than ideal levels.

A focus on eating real, whole foods, especially those “clean” sources of protein, is a good way to naturally hike up the levels of l-arginine you are consuming each day. Complete proteins are the most beneficial since they not only supply l-arginine, but also other important nutrients and minerals the body needs.

Salmon and other wild-caught fishes are a great source of l-arginine, as well as providing the anti-inflammatory benefits of omega-3 acids. They can also naturally help balance and maintain overall cardiovascular health. You can rely on sources other than animal proteins as well, including nuts and seeds, coconut products, sea vegetables, whole grains, beans, and other protein-rich foods. Denser protein sources are the better option.

Still not sure what foods to incorporate in your diet? Consider some of these options:

-          Cage free eggs and dairy products like kefir, raw cheese, and organic products.

-          Grass-fed beef/meat, and pasture raised poultry and turkey.

-          Liver and organ meats, wild caught fish.

-          Sesame, pumpkin, sunflower seeds.

-          Spirulina, seaweed, and sea vegetables.

-          Walnuts, Brazil nuts, almonds, and coconut meat.

Although not an inclusive list, these are a few foods which are extremely high in l-arginine levels, and should be incorporated in to your diet when all possible.

How much should you consume –

As detailed above, every individual produces varying levels of l-arginine daily. That is why it is important to know what the recommended dosage levels are, as well as how much you are getting from your diet, in order to ensure you are consuming sufficient levels daily.

It is best to get the source of l-arginine from your diet and natural food sources when possible. The supplement is sold over the counter, and you can also obtain a prescription for your doctor, in the event you are required to take a higher dosage level.

Prescriptions are often given to treat heart disease, migraines, certain infections, and can even be used in treating diabetes, or HIV/cancer. Of course, no two people are the same, so the types of treatment, and prescription options are going to differ, based on your doctor’s recommendations.

What are proper dosage levels? –

This will vary; the main factor which determines this is what you are trying to treat when using an l-arginine supplement. If you are using it to treat a heart condition or ED, 3-6 grams daily is typically a good level to begin with. If it is simple being used to help increase energy levels and enhance exercise performance, some people will take dosage levels up to 9 grams per day. For those who are generally healthy, and using it to prevent inflammation/benefit from better circulation, 1 gram is typically the recommended dosage.

With higher dosage levels, also comes the higher potential for the side effects, so this is something to note when taking a supplement. Research also suggests that more is not always the best approach, when treating blood flow, so this is something to discuss with your doctor as well before you begin a dosage cycle of the supplement.

Possible interactions/side effects –

It is generally safe to consume, as is the case with other vitamins, minerals, and amino acid supplements. But, there is always the potential for side effects, especially if you are taking other medications, or if you are on any other prescription drugs. So, make sure you do discuss this with your doctor before you begin a dosage cycle.

If you have history of heart disease, if you suffer from low blood pressure, diabetes, kidney failure or problems, or have an active virus, you should speak to your doctor before you start using l-arginine as well. This is the only way to ensure it is safe for consumption and daily use.

If consuming from natural food sources, there isn’t a danger in ingesting l-arginine levels. With this being said, you should note that higher doses might complicate a condition, especially if you are on other medications, or if you take other prescription medications. So, before you begin, talk to your doctor, to find out what recommended levels or dose you should begin with.

For individuals who are generally healthy, you might still experience side effects including: abdominal pain, diarrhea, worsened allergies, gout, bloating, or asthma. Low blood pressure is often complained of as well. In some, l-arginine can cause allergic reactions, or increased swelling in the lungs/airways. If you suffer from asthma, this should be noted prior to starting to consume the supplement.


It is also important to note, that l-arginine appears to be safe for women who are pregnant, and children. However, not much research has been conducted. It is best to begin at a low dosage level, and to speak to your doctor before you begin to use a supplement if you a pregnant or nursing.

About the author

Dr. Constance Odom, MD

5 min read