Last updated: 17/10/2022


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Some people love to work out and spend lots of time in the gym, the pool or outside. Others hate even the idea of exercising and everything associated with it: exhaustion, muscle fatigue and injuries. If you are part of that second group of people, you’ll find this article particularly interesting.

L-arginine is a compound which is well-known in the field of sports supplements. This amino acid can boost physical performance, especially for people with poor or little training, reduce fatigue and speed up recovery after exercise.  If you’d like to know more, keep reading!

Key Facts

  • L-arginine is an amino acid essential to protein synthesis. It is also a precursor to the vasodilator compound nitric oxide.
  • L-arginine promotes the process of vasodilation which not only supports blood circulation to the muscles, it can also lower arterial tension and improve the symptoms of erectile dysfunction.
  • L-arginine can be especially useful for people with poor training or with specific symptoms but does not have great effects for young and healthy people.

Our Selection: The Best L-Arginine Supplements

How can you choose the best L-arginine supplement? If you don’t want to spend hours and hours pouring over the characteristics of hundreds of different products, we can advise you to check this section, in which we will show you the best L-arginine supplements currently available on the market.

Buyer’s Guide: Everything You Should Know About L-Arginine

Arginine is an amino acid with vital importance for the proper functioning of the body, regulating from cell reproduction to ammonia elimination. Its active form, L-arginine, is appreciated as a dietary supplement in the sports field, where it is used to improve the performance of athletes.

New to the gym? L-arginine can deliver the extra energy you need to survive those first tough days.
(Source: Luckybusiness: 72211416/

What is L-arginine exactly?

Arginine (or L-arginine, its active form) is a molecule necessary for protein synthesis. It is considered a “conditionally essential” amino acid as it can normally be synthesised from citrulline (an amino acid), although in extreme ages of life and stress situations it needs to be obtained from food.

Synthesis and absorption of L-arginine mainly take place in the gut. Stressful events (accidents, injuries and diseases) can alter these processes, leading to a situation that can decrease the available concentration of this amino acid in our body.

L-arginine is commonly used by atheletes.
(Source: Dolgachov: 54750894/

Arginine allows the formation of another compound of nitric oxide (which molecular formula is NO). NO works as a vasodilator and therefore, it is a potential ally against those pathologies causing an alteration in blood flow, such as hypertension, coronary heart disease and even erectile dysfunction.

Amino acids can have the form “L-” or “D-“. The “L-” molecular configuration is active and beneficial for the cells, while “D-” indicates inactivity.

What are the functions of L-arginine?

L-arginine has multiple functions, all of them are vital for the proper functioning of the body. You can consult the following table to find the most important effects of this amino acid according the different systems in the human body.

System/Organ L-arginine function Effects
Skin Cell division Heals wounds, reduces scars and creates a new epithelial cells
Musculoskeletal Hormone release (particularly growth hormone and insulin) and amino acid synthesis Muscle growth
Liver Urea metabolism Eliminates excess ammonia in the blood
Cardiovascular NO synthesis Vasodilation, reduction of blood pressure and increased muscle perfusion
Digestive system Amino acid synthesis (glutamine y proline) Maintanence of immunity (blood-brain barrier)
Immune system Lymphocyte activation Promotes immunity

The most recognised function of L-arginine is its role as a precursor to vasodilator, nitric oxide. However, its other functions are equally important. This amino acid was attributed with ergogenic properties, that is, the ability to increase the strength of the body physical work.

Why can I have poor levels of L-arginine?

Severe arginine deficiency is very rare. The presence of this amino acid in a large number of foods and the body’s ability to create it from citrulline makes its deficiency uncommon. Even so, it will be possible to identify three types of L-arginine deficit:

  • Severe arginine deficiency in the diet: This deficiency will only appear in states of malnutrition, in which no solid food is ingested for a long period of time.
  • Increased catabolism (destruction) of arginine in blood: This occurs in certain diseases, such as thalassemia, asthma, malaria and cystic fibrosis.
  • Decreased endogenous synthesis of L-arginine: The body may stop creating arginine from other amino acids. This may occur as a result of aging. In this case, L-arginine will behave as an essential amino acid (which must be obtained directly from food).

Keep in mind that during pregnancy there is a physiological decrease in L-arginine. This causes some inhibition of the immune system, which prevents the mother’s body from recognising her future child as an invading element. This allows embryo implantation and fetal growth.

How does a lack of L-arginine affect my health?

L-arginine decrease below normal levels will disturb the general well-being of those affected. In case of diseases (such as asthma) that raise the rate of arginine destruction, more severe symptoms will take place, taking longer to disappear if this amino acid is not supplemented.

Furthermore, a lack of L-arginine directly affects the responsiveness of the immune system. Medical research has found links between a loss of arginine secondary to an injury or accident (like myocardial infarction) with reduced healing rates compared to other patients.

No supplement can replace a healthy, balanced diet.
(Source: Choreograph: 26786355/

In healthy adults, L-arginine deficiency has been linked to an increased risk of cardiovascular events, such as hypertension, angina pectoris or myocardial infarction. On the other hand, a lack of this amino acid could affect the functioning of testosterone, impairing muscle growth and sexual potency.

Did you know that research Robert Furchgott, Ferid Murad y Louis Ignarro recieved the Nobel Prize for Medicine in 1998 for their research into the use and clinical applications of nitric oxide?

How to increase my L-arginine levels from the diet?

You can find a large number of foods rich in arginine. Although higher levels are found in animal-based foods (meat, eggs and dairy), it is also found in fruits, vegetables and legumes. You can consult the following table to find the main nutritional sources of arginine:

Food Approx arginine content (grams)
Turkey (medium breast fillet) 16g
Pork rib (medium portion) 14g
Chicken (medium breast fillet) 9g
Pumpkin seeds (100g) 6g
Soy beans(100g) 4g
Lentils (100g) 1.1 g
Chickpeas (100g, cooked) 1g
Semi-skim milk (1 glass) 0.2 g

Although there is no clear recommendation on its daily intake, a balanced diet is estimated to provide about 5.5 grams a day of this compound. Omnivorous people will easily reach the suggested amount, while vegans and vegetarians will need to monitor their diet to ensure they meet the requirements.

Who could benefit from an L-arginine supplement?

Most healthy people will be able to maintain healthy levels of L-arginine through diet or by synthetising it from other amino acids. However, there are some people who could benefit from an extra contribution with a food supplement:

  • Vegan and vegetarian people with unbalanced diets.
  • Athletes prone to injury.
  • People starting a new exercise routine.
  • Young or middle-aged men suffering from erectile dysfunction.
  • Women with sexuality-related issues (anorgasmia or lack of lubrication).
  • People undergoing physical or psychological stress.
  • People diagnosed with “prehypertension” or at high risk of developing hypertension.
  • People with elevated LDL (“bad cholesterol”) cholesterol levels.
  • Elderly people, especially if they suffer from arteriosclerosis or other cardiovascular risk factors.
  • Convalescent people (especially after traffic accidents, major burns and other serious injuries).
  • People with intestinal and malabsorption pathologies.

L-Arginine is an amino acid which is critically important for the proper functioning of the body.
(Source: 85870822/

This amino acid could also be useful to all people who want to fight “oxidative stress” (the main phenomenon responsible for aging). This presumed function of L-arginine is still under study and needs to be validated with more clinical studies.

How does L-arginine supplementation benefit my health?

Several studies have shown that L-arginine is capable of causing vasodilation in the cardiovascular system to lower blood pressure. This way, supplementation with L-arginine improves the health of people with the following cardiovascular risk factors:

  • Hypertension: Supplementation with L-arginine moderately reduces mean arterial pressure (between three and five points). People with “prehypertension” (who are often recommended to adopt healthy lifestyles) can use this supplement to control their blood pressure.
  • Obesity and hypercholesterolemia: Obesity and elevated LDL cholesterol levels are related to high blood concentrations of homocysteine ​​and ADMA, two chemical compounds that are related to worse cardiovascular health. The use of L-arginine reduces the levels of these two substances and decreases coronary risk.
  • Diabetes: Poorly controlled diabetes accelerates oxidative stress, damaging blood vessels and causing the formation of cholesterol plaques in arteries. Although L-arginine is not able to improve glucose intolerance, it does oppose oxidation and premature arterial aging.

Pregnant women with preeclampsia (a potentially serious disease that manifests in high blood pressures during pregnancy) will also benefit from the use of L-arginine. Due to the danger of this disease, it is recommended to supplement under your doctor’s supervision.

L-arginine can help you to overcome moments of stress.
(Source: Media Ltd: 47404364/

In healthy people, with normal blood pressure and healthy cholesterol levels, supplementation with L-arginine has not shown to produce a protective effect against heart disease. Healthy people will benefit more from a healthy lifestyle (Mediterranean diet, exercise and drug abstention).

How will L-arginine benefit me in sports?

There is great controversy about the use of L-arginine supplements in sports. While many fitness enthusiasts recommend it as a miraculous compound to improve athletic performance and physical fitness, some others classify it as “a waste of money”. What is the truth?

  • L-arginine in trained subjects: There are several studies that find no relationship between taking L-arginine and athletic performance of young, healthy, athletic men. In other clinical trials, an increase in aerobic endurance and post-ground recovery was found.
  • L-arginine in untrained subjects: Taking L-arginine before starting a training routine does seem to improve physical capacity and recovery time in people who are not used to exercise.
  • L-arginine and age: Young men (16-35 years) do not seem to benefit much from this supplement as other groups. However, in elderly people (sixty years and older) there is a positive effect on muscular blood flow and resistance to aerobic exercise.
  • L-arginine and physical appearance: This supplement produces non-permanent changes in muscles appearance. By increasing the blood flow to the muscles, it is possible to observe dilated blood vessels and more bulky muscles (“pump” effect) during the hours following the taking of the supplement.
  • L-arginine and changes in body composition: Supplementation with L-arginine is not directly related to a decrease in body fat or significant weight loss. However, increasing physical endurance will allow for greater physical activity that, consequently, will stimulate weight loss.
  • L-arginine and recovery: It has been observed in several studies that this supplement is able to increase the rate of lactic acid elimination (a marker of muscle depletion) from the blood. It also seems to accelerate muscle regeneration after injuries.

In conclusion, L-arginine seems to favor training capacity in people who are not used to exercise and wish to start a new fitness routine. Fitness enthusiasts can use this supplement to speed up their recovery after an injury or after an especially intense session.

Can L-arginine treat erectile dysfunction?

The term “erectile dysfunction” refers to the difficulty or inability of man to achieve an erection that allows him to maintain full sexual relations and a satisfying sex life. Although this affects older men more frequently (usually those aged forty or over), it can appear in men of any age.

Under normal conditions, vasodilation of blood vessels is needed to supply the structures of the penis to achieve an erection. Drugs used to treat this dysfunction (such as sildenafil or Viagra®) will promote the synthesis of nitric oxide and allow erection.

L-arginine, a compound that also facilitates the synthesis of nitric oxide, has been used as a treatment for mild erectile dysfunction in some studies. Combined with other compounds such as Pycnogenol or yohimbine, this amino acid seems to be able to improve the symptoms of erectile dysfunction.

Can L-arginine improve female sexual health?

Female anatomy responds to sexual stimuli similarly to male. In women, the increase in blood flow to the genital area (caused by vasodilation) favours an increase in libido and makes it easier to reach orgasm. The use of NO precursors will promote this vasodilation.

After testing the combination of L-arginine and Pycnogenol in women in childbearing age, these supplements confirmed to also improve sexual health in users.

Unlike other medical treatments for increasing female libido, the combination L-arginine + Pycnogenol produced no side effects.

Can L-arginine improve the appearance of skin?

L-arginine favours the creation of new cells and increased blood perfusion. As a result, it accelerates wounds healing. Moreover, its users usually report an improvement in skin, hair and nails texture after a month of supplementation.

However, these benefits are related to the intake of an L-arginine supplement. Although many cosmetic companies have started to produce different products with this amino acid in their composition, topical application of L-arginine has not been shown to produce any improvement in the appearance of skin.

Ernesto BarbosaFamous Colombian Plastic Surgeon, International Leader in His Field
“L-arginine is an essential amino and strong, economic anti-oxidant which keep your skin young. It is a marvellous tool for rejuvenation”.

In summary, what can I expect from L-arginine supplementation?

Regardless of your reasons for using an L-arginine supplement, after a month of continued use you will notice a general improvement in your physical and mental well-being. In a survey on the effects of L-arginine, people who used this supplement for four weeks reported the following findings:

  • Increased ability to concentrate
  • Increased ability to memorise information
  • Reduction of mental fatigue
  • Reduction of anxiety symptoms and nervousness
  • Better tolerance to psychic stress
  • Improvement of sleep quality, with less awakening through the night
  • Increased energy, especially after waking up
  • Mood improvement
  • Increased physical performance
  • Delay of physical exhaustion
  • In men, increased sexual capacity
  • A general, subjective feeling of well-being

These results seem to indicate the use of L-arginine goes beyond gyms or sports centers. Supplementation with this amino acid, especially during periods of physical or psychological stress, could help maintain a good quality of life in both sedentary and sports people.

Problems with sex life affect men and women equally. L-arginine supplement can help maintain satisfactory sexual relationships.
(Source: Białasiewicz: 32791971/

How to use L-arginine supplements?

L-arginine supplements can be used very differently depending on the desired effect. In general, it’s recommended to take three to five grams a day, and better with food. Check the table below for more details:

Use Dosage Time interval
Improves performance (intervals) 3 grams per day 30 minutes before training (specific days)
Improves performance (daily training and high intensity) 3-6 grams per day 30 minutes before training (daily)
Treatment of erectile dysfunction 5-6 grams per day 1-2 hours before sexual relations, before bedtime
Boost libido in women 5-6 grams per day 1-2 hours before sexual relations
Improves quality of life (reduces blood pressure, slows aging and improves skin texture) 1 gram per day Take with one of your main meals
Dietary supplement for vegans and vegetarians 1 gram per day Take with one of your main meals

In conclusion, supplementation with L-arginine should be tailored to individual objectives and characteristics of each person. After four weeks of use, you should reevaluate its effectiveness and decrease or increase the dose according to the ever changing needs of your body.

Are L-arginine supplements safe?

L-arginine has been used for years as an element of supplementation. In most people, it is considered safe for consumption even at high doses (30 grams/day). If ingested a dose larger than recommended, gastrointestinal discomfort may appear and it will be resolved by decreasing the dosage.

On the other hand, people with generally low blood pressures (equal to or less than 110/70 mmHg) should take special care when using this supplement. Its vasodilator action can further decrease blood pressure, causing dizziness and a weakness sensation.

Another complication that may be associated with taking L-arginine is the recurrence of cold sores. Some experts have observed rebounds of this virus in people who recently began to supplement with this amino acid. Cold sores are not dangerous for most individuals but very annoying.

Oral herpes can reactivate when taking L-arginine supplements.
(Source: Loganban: 27857026/

What side-effects do L-arginine supplements have?

Despite the safety of L-arginine, the close relationship between this amino acid and nitric oxide can cause some side-effects. These recommendations affect very specific groups of people who must weigh up the risks and benefits before supplementing:

  • Pregnancy and lactation: Although L-arginine can be used as a treatment for preeclampsia, it is recommended not to use it without explicit medical recommendation during pregnancy and lactation.
  • Under eighteen: L-arginine is considered safe in adults. However, in children, taking a high dose of the product can cause serious side effects or even death. Therefore, the use of this substance without medical supervision is not recommended.
  • Asthma or allergies affecting airways: In asthmatic people or those with angioedema predisposition (generalised swelling of the skin and mucous membranes, capable of causing asphyxiation if it occurs at the throat level) the use of this supplement may cause new allergy attacks. Caution is recommended during consumption.
  • Cirrhosis or liver disease: Generally, people with liver disease should consult a specialist before taking any supplement, especially if it has a high amino acid content.
  • Specific enzyme deficiencies: There are people affected by a genetic mutation that prevents them from taking advantage of and using L-arginine. Supplementation is not recommended in these people.
  • Cardiovascular pathology (especially with a history of myocardial infarction): Although L-arginine may decrease vascular risk in people with risk factors, it can be more harmful than beneficial in people recovering from a cardiovascular event. Its use is not recommended without prior medical authorization.
  • Kidney disease: People with kidney problems may have trouble regulating their blood electrolyte levels (especially sodium and potassium). L-arginine could raise potassium levels in these people and cause a dangerous imbalance. Arginine supplementation is not recommended in these people.
  • Diabetes: L-arginine may affect the control of some people’s diabetes. It is recommended to make a more careful blood glucose monitoring during supplementation with this amino acid.

In a 2013 study, long-term effects of L-arginine supplementation were assessed. It was concluded that this amino acid loses its effectiveness and increases oxidative stress with continued use. It might be a good idea to limit supplementation to short periods of time (before the exercise or intimate relationships).

Shopping Criteria

L-arginine is a safe and effective product if used carefully. However, its popularity has caused products with a lower quality than desirable to appear. To get the most out of this substance, we advise you to use these purchase criteria when choosing your new supplement:

Drug Interactions

L-arginine is able to interact with the active substances of some drugs used by many people in our country. Most of these medications are antihypertensive drugs, which function would be excessively enhanced by the vasodilator action of nitric oxide.

Therefore, talk to your doctor before using this amino acid if you are taking antihypertensive medication. It may be necessary to decrease the dose of your supplement or drug to avoid any complication. Nitrates (antianginal treatment) and sildenafil can also cause interactions.

Vegan or Vegetarian Nutrition

Although animal-based foods are the richest in this amino acid, there are supplements specially made for vegetarian or vegan consumers. These items are synthesised from nuts, legumes or seaweed (such as spirulina) and are free from animal-based elements.


Allergic reactions to L-arginine have been described. As a precaution, it is recommended to immediately stop using it if having vomit, diarrhoea, severe discomfort, feeling of suffocation, muscle aches or cramping immediately or after a few hours of intake. This reaction is, fortunately, very rare.

People intolerant to gluten, lactose, nuts, fish or soy should carefully examine the labelling of L-arginine supplements before deciding on one. Depending on the manufacturing conditions, one or more allergens may be found.

Remember that hydration is indispensable when taking any supplement.
(Source: Simons: 35335487/


Supplementation with L-arginine can be done by using different formats. Leaving aside injectable form (available only in medical and hospital settings), it can be found in different presentations that will affect our final experience with the product:

  • Tablets and pills: This format allows a quick and convenient supplementation. Containers are generally small and easy to transport. Its disadvantage lies in the difficulty of modifying the dose in a more personalised way.
  • Powder: L-arginine powder offers many more possibilities for dose adjustment. Supplementation fans will benefit from this format. Other people, however, may find it annoying to have to mix and dose this type of item.
  • Creams, shampoos, serums and conditioners: As L-arginine is supposed to have regenerative properties for skin and hair, some cosmetic companies have created topically applied products rich in this amino acid. Its real effectiveness is very debatable.

L-arginine supplements can also be sold in combination with “alpha ketoglutarate”, labeled under the acronym AAKG (Arginine Alpha Ketoglutarate).

Alpha ketoglutarte is an essential compound for producing energy at the mitochondrial level. Adding it to a supplement does not seem to impact on its effectiveness.


Although L-arginine is safe even at high doses, some studies have found a problematic relationship between the consumption of this supplement at doses above the recommended and brain damage secondary to an exaggerated increase in NO levels. Choose supplements that do not exceed the recommended daily dose of 6 grams/day.

Value for Money

If you want to make a smart purchase, choose items that contain doses within the recommended range (3-6 grams). In addition, assess whether the sum of other components that raise the original price of the supplement is really beneficial (as in the case of L-arginine + pycnogenol to treat erectile dysfunction).

Jillian LevyPsychologist and Holistic Therapist
“The benefits of L-arginine go beyond NO production for better circulation. You will find that is has important roles in the nervous system, cellular reproduction and the fight against oxidative stress which leads to disease and aging”.


Adding an L-arginine supplement to your regular diet can give you that boost you need to maintain your exercise routine or take up a more intense one. Its consumption times of particular moments physical or psychological stress will help give you the energy and vitality you need to cope with life’s challenges.

L-arginine may not help you win your next fitness competition. However, it will be able to improve your overall health by controlling your cholesterol levels, curbing high blood pressure and fighting against premature aging. So what are you waiting for?

If you liked our guide on L-arginine, share this article! Do not hesitate to send us your doubts, comments and suggestions.

(Source of featured image: Losev: 84202324/