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!
- 1 Weekly newsletter with the best personal finance tips
- 2 Key Facts
- 3 Our Selection: The Best L-Arginine Supplements
- 4 Buyer's Guide: Everything You Should Know About L-Arginine
- 4.1 What is L-arginine exactly?
- 4.2 What are the functions of L-arginine?
- 4.3 Why can I have poor levels of L-arginine?
- 4.4 How does a lack of L-arginine affect my health?
- 4.5 How to increase my L-arginine levels from the diet?
- 4.6 Who could benefit from an L-arginine supplement?
- 4.7 How does L-arginine supplementation benefit my health?
- 4.8 How will L-arginine benefit me in sports?
- 4.9 Can L-arginine treat erectile dysfunction?
- 4.10 Can L-arginine improve female sexual health?
- 4.11 Can L-arginine improve the appearance of skin?
- 4.12 In summary, what can I expect from L-arginine supplementation?
- 4.13 How to use L-arginine supplements?
- 4.14 Are L-arginine supplements safe?
- 4.15 What side-effects do L-arginine supplements have?
- 5 Shopping Criteria
- 6 Summary
- 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
What is L-arginine exactly?
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.
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.
What are the functions of L-arginine?
|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 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?
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.
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.
How to increase my L-arginine levels from the diet?
|Food||Approx arginine content (grams)|
|Turkey (medium breast fillet)||16g|
|Pork rib (medium portion)||14g|
|Chicken (medium breast fillet)||9g|
|Pumpkin seeds (100g)||6g|
|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?
- 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.
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?
- 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.
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?
- 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?
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?
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?
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.
In summary, what can I expect from L-arginine supplementation?
- 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.
How to use L-arginine supplements?
|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?
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.
What side-effects do L-arginine supplements have?
- 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).
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:
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.
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).
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).
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?
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