L-Arginine guide: benefits, foods, uses & side effects

L-arginine, or just arginine, is one of 20 naturally occurring amino acids in the body.

In this article you will discover the many health benefits it could have for your body. It may be hard to pronounce, but L-arginine (which sounds like ar-jen-nen) has a lot going for it.

Sometimes just called arginine, it’s one of 20 different amino acids in the body, and a bit of an unsung hero when it comes to health benefits.

What is L-arginine?

L-arginine is a naturally occurring amino acid that your body needs to make protein.

Your body will usually make all the l-arginine it needs, but also It’s found in:

• Red meat
• Poultry
• Fish
• Dairy products

It can also be found in supplement form and acts as a vasodilator which means it helps open blood vessels.¹

It also helps with circulation and creating energy.

For this reason, it may be that your need for L-arginine surpasses the body’s ability to produce or consume its natural doses.

While this is rare, in the cases it does occur it is often within older adults or people with medical conditions that need attention.

Other names for l-arginine

L-arginine is often known medically and scientifically by a number of different names, which include:

1. L - arginine
2. Arg
3. Arginine
4. Arginine hydrochloride
5. L-arg
6. NG-monometyl-L-arginine
7. Dipeptide arginyl aspartate
8. HeartBars
9. 2-amino-5-guanidinopentanoic acid
10. Sargenor
11. Spedifen

For ease, within this article we’ll be referring to it as l-arginine and arginine, to save any further confusion.

What does l-arginine do?

As mentioned, arginine is an amino acid that helps you build protein within your body. You can find out more about amino acids and proteins below.  

But more recently, studies into l-arginine have been around the potential benefits that it can have for your heart.

The main functions within the body are said to be:²

• Helping the kidneys remove waste from the body
• Maintaining immune and hormone function
• Expands and relaxes the arteries

Some evidence suggests that arginine may help improve blood flow in the heart’s arteries. It is thought that this may help with clogged arteries, chest pain and in some cases angina or coronary artery disease.

However, the long-term use of arginine effects on cholesterol and heart health are still yet to have any full data available.³

What are amino acids?

Put simply, amino acids are the building blocks of protein which help build muscle. A long chain of amino acids creates a protein, making them very important for good health.

They’re made from different compounds and there’s around 20 of them in total which all play their part in helping the body function and stay healthy.

What are proteins?

Proteins provide a range of functions in the body, including creating muscles, hormones and antibodies.

Protein is also needed to support your hair, skin (collagen) and nails.

It's also responsible for the formation of enzymes hormones and the development of bone, cartilage and blood.

Where does L-arginine come from?

Like many other amino acids, L-arginine is found in animal produce including fish, chicken, eggs and dairy.

It’s also in grains, beans, corn, and nuts – but not in fruits or veg.

However, protein-rich foods only provide relatively small amounts of any given amino acid, so arginine supplements may be useful for some people.

Handpicked content: Why do we need protein? 

How does L-arginine work its magic?

Once it’s in your body, arginine is transformed into the hormone nitric oxide.

Hormones are chemical ‘messengers’ that trigger key processes and functions in the body. 

Nitric oxide is responsible for opening up the blood vessels and encouraging better blood flow to all parts of the body such as the arms, legs, head and genitals.

9 L-arginine benefits

1. May help migraines and hypertension

Because of its supersonic capacity to help with blood flow, L-arginine is sometimes taken to help with migraines and hypertension, and to enhance heart health and immunity.

2. May help anti-ageing

One 2010 study even suggested that L-arginine might have anti-ageing benefits.

This is largely thanks to its relationship to an increase in human growth hormone (the production of which drops off as we age), which helps us recover from workouts, improves strength, and enhances libido and muscle growth.⁴

3. Helps with production of creatine

It also pumps more blood to your muscles, increasing that full look known as ‘the pump’, so it’s commonly found in pre-workout powders.

It’s used by sports people to aid performance too, because it helps with the production of creatine, a naturally occurring acid that enhances power output.⁵

4. May help with chest pain

By taking l’arginine supplement you may see an improvement of symptoms of angina, and other chest pains.

A 2009 study says that arginine supplements may improve exercise tolerance and quality of life in people with angina. Although more longer-term research is needed.⁶

5. May support those with erectile dysfunction

A March 2020 study revealed that taking between 2.5 to 5 grams of l arginine supplements seems to improve sexual function in men who have erectile dysfunction.

Lower doses are thought not to be as effective, there is firm evidence that taking l-arginine with maritime pine bark extract, along with other ingredients may improve sexual performance.⁷

6. Could help maintain normal blood pressure

There is evidence that taking L-arginine by mouth can help normalise blood pressure in healthy people, people with high blood pressure, and people with slightly high blood pressure with or without diabetes.

7. May prevent inflammation in infants

A 2017 study into necrotizing enterocolitis or NEC, a serious intestinal disease in premature infants, found that adding L-arginine to formula seems to prevent inflammation of the digestive tract.⁸

8. May narrow blood vessels

Research shows that taking L-arginine for 8 weeks increases blood flow in people with peripheral arterial disease.

This is thought to work as the arginine amino acid changes into nitric oxide in the body, which helps relax blood vessels and helps blood circulation.

9. May help control blood pressure during pregnancy

A 2006 study on pregnant women who were all of similar age, height and weight showed that L-arginine can reduce blood pressure in pregnant women with pre-eclampsia.

L-arginine also seems to keep pregnant women from developing pre-eclampsia.⁹

10 of the best arginine foods

It is possible to increase your l’arginine levels naturally through food. Arginine foods are easy to come by and purchase in shops.

You can find arginine in the following:

1. Turkey

The highest amount of arginine you can find is in turkey breast. Amazingly, one cooked breast contains 16 grams of l-arginine!

Turkey is not only a great source of proteins, but it also has a high concentration of other nutrients such as B vitamins and Omega-3 fatty acids.

2. Pork loin

Pork loin comes in at a close second.

Due to its high-protein levels, it has an arginine content of 14 grams. Loin is one of the leanest cuts of pork, so it’s low in fat too.

You can add a marinade for extra flavour, without the fat.

3. Chicken

Another healthy way to get protein is through chicken.

It’s a great source of arginine, one breast has 70% of your daily protein and 9 grams of arginine.

4. Pumpkin seeds

You’ll be happy to know that meat isn’t the only source of protein and arginine.

It’s thought that 6Oz of pumpkin seeds has almost 7 grams of arginine.

They’re also a great source of iron and zinc.

5. Soyabeans

Soyabeans are also another good source of arginine.

6Oz of soyabeans contains 4.6grams of arginine. They’re also high in potassium and magnesium.

6. Peanuts

Peanuts are a great source of l-arginine, with 4.6 grams per 6Oz.

However, the downside to peanuts is that they contain a lot of fat – so it's unlikely that you’d eat them all in one sitting.

In addition to their high protein content, peanuts are a great source of vitamin B3 and vitamin E, folate and niacin.

7. Spirulina

Spirulina is a powerhouse when it comes to nutrients.

It contains 4.6grams of l-arginine per 6Oz, it also contains high levels of calcium, iron, potassium and niacin.

The most likely use of spirulina is for a smoothie, which you’d normally use around a tablespoon which would give you around 0.28 grams of arginine.

8. Dairy products

Dairy products such as milk, cheese and yogurt are great sources of arginine.

6Oz of milk contains about 0.2 grams, and 4 ounces of cheddar cheese contains about 0.25 grams.

9. Chickpeas

Chickpeas are an excellent source of arginine, as well as protein and fibre, particularly if you don’t eat meat.

6Oz of cooked chickpeas contains 1.3 grams of arginine, 14.5 grams of protein and 12.5 grams of dietary fibre.

Why not try our Rebel Recipes turmeric hummus as a nice arginine-full treat?

10. Lentils

If you’re on a plant-based diet, lentils are another great source of protein fibre, and of course arginine.

There’s around 1.3grams per 6Oz, but there is also around 63 percent of your daily dietary fibre.

When to take l-arginine

In scientific research the dosage of arginine is often quite hight, between 3-5 grams or even 6 – 30 grams for some studies.

However, it’s recommended that the daily dosage of l-arginine is to be kept under 9 grams per day to avoid potential gastrointestinal side effects, such as:

L-arginine side effects

• Nausea
• Diarrhea
• Bloating

L-arginine should be taken at least 3 times a day: in the morning and like other single amino acids, it’s recommended to take L-arginine between meals for maximum absorption.

Is L-Arginine safe to take daily?

Yes, like other amino acids – it's safe to take l-arginine on a daily basis.

Last updated: 16 July 2021