L-arginine is a proteinogenic, semi-essential amino acid. In contrast to the other amino acids occurring in the body, L-arginine contains 4 nitrogen groups in the molecule, which are probably responsible for the vasodilating effect of L-arginine. L-arginine can be ingested through food as well as formed by the body itself from other amino acids (therefore semi-essential). L-arginine plays an important role in the body as a neurotransmitter and as a building material for other body tissues.

Function and effect

L-arginine has many important functions in the body and acts in different places. Among other things, it is responsible for the communication of blood vessels and the regulation of the immune system. It is used medically for:

  • Diabetics to improve insulin resistance
  • Tinnitus patients and people with hair loss to improve capillary blood flow
  • arteriosclerosis
  • Optimization of the intraocular pressure
  • Improvement of the ability to concentrate
  • Erectile dysfunction and sperm production promotion
  • Strengthening the immune system

L-arginine also fulfills many important functions in the body:

  • As a neurotransmitter, it is involved in the control of blood vessels
  • In the protein metabolism, it ensures that ammonia is converted into urea
  • When building muscle, L-arginine is involved in the release of the growth hormones glucagon and prolactin and also plays a role in the biosynthesis of creatine.

Side effects

Since L-arginine is an endogenous substance, there are almost no side effects with normal intake. Clinically speaking, no side effects are known up to an intake of 15,000 mg per day. So positive side effect can be observed an improvement in general immune behavior. Nevertheless, there are a few things to keep in mind when supplementing with L-arginine. These include, for example:

  • In herpes patients, L-arginine should only be taken in conjunction with L-lysine, otherwise its use is not recommended as it can have a negative effect on the herpes

  • If prescription drugs are taken, a doctor or pharmacist should be consulted beforehand so that possible interactions can be excluded

  • L-arginine should be crept in so that no symptoms occur. This means that the dose will be increased slowly over a longer period of time.

  • People who take PDE-5 inhibitors (Viagra, Sildenafil, etc.) should speak to their doctor, as L-arginine can greatly increase the effectiveness of these agents.

  • If taken at the same time as Biosperin, this can promote the effect of L-arginine

Who is L-arginine suitable for?

In order to achieve a therapeutic effect with L-arginine, a daily intake of 3000mg L-arginine is necessary. L-arginine is present in many foods, but it is rarely absorbed to the extent necessary to be therapeutically effective. As already mentioned, L-arginine can achieve positive effects in a variety of complaints and clinical pictures as well as in muscle building and endurance sports, which is why it makes sense as a supplement. This applies in particular to people with diseases such as diabetes, erectile dysfunction, cardiovascular problems (e.g. high blood pressure) and immune deficiency.

L-arginine can also help during pregnancy and to increase general well-being. How high the requirement for L-arginine is depends on various factors. Age, fitness level, state of health and special loads such as stress or sport are some of them. Overall, the individual L-arginine requirement and the question of whether supplementation is necessary must always be decided on a case-by-case basis and preferably with the advice of a doctor.

also read: Amino acids and exercise

L-arginine for muscle building

L-arginine is also of particular importance for building muscle. Due to the chemical characteristics of the molecule already mentioned, the body is able to produce nitric oxide (NO) in a combination of L-arginine with oxygen. Nitric oxide fulfills many functions in the body. The main focus here is now on the vasodilating effect. The nitric oxide improves blood circulation, which has a positive effect on the entire cardiovascular system. L-arginine is therefore not only of particular importance in natural foods but also as a dietary supplement, for example for building muscle in weight training, as it can indirectly promote muscle building through its vasodilating effect.

Due to the improved blood circulation, the muscles can be better supplied with oxygen and important nutrients, which can increase training performance. An increased nitric oxide level also ensures that the muscle cells grow and more lean muscle mass is built up. L-arginine stimulates the formation of the growth hormones prolactin and glucagon, which among other things are responsible for increased fat burning and improved muscle building. Due to the positive effects of L-arginine on the immune system, injuries can heal faster, so that the regeneration time of the muscles can be shortened. L-arginine also supports the body in breaking down waste products such as lactate and other end products of biosynthesis, which also has a positive effect on the regeneration time. On a psychological level, L-arginine improves the ability to concentrate and short-term memory and has a positive effect on training motivation.

In order for L-arginine to support muscle building in the manner mentioned, a daily intake of 2000-5000mg L-arginine is necessary. The positive effects of L-arginine have already been proven in various studies. As a side effect to the ingestion, positive effects on the blood pressure and the oxygen supply in the entire body were also found in the test persons. Overall, L-arginine has numerous properties that have a positive effect on muscle growth and general performance. It is not without good reason that these properties have led to L-arginine being a popular dietary supplement in the sporting sector for years.

More on this: Building muscle with amino acids


In addition to many foods, L-arginine can of course also be supplemented directly. There are also various dosage forms of the amino acid such as powder and capsules.

The powder is easy to dose and can be stirred into drinks and food. There are two different types of powder. L-arginine base powder consists of 100% L-arginine, but has a strict, bitter to fishy taste. L-arginine HCL powder, on the other hand, consists of 75% L-arginine. The added hydrochloride neutralizes the taste, so that children can also take the powder without problems. The disadvantage, however, is that HCL is not well tolerated by the body in large quantities.

The dose is already specified in capsule form, capsules are easy to use and can be taken conveniently on the go. The inherent taste is not a problem due to the fact that the capsules only dissolve in the stomach, but they are rather unsuitable for people with swallowing difficulties and small children. Due to the easier handling of the capsules, however, they are often significantly more expensive than the L-arginine powder.

Also read: Creatine capsules

Recommendations for ingestion

When taking L-arginine to improve performance in sports, various intake criteria must be observed. On non-training days, the dose should be taken immediately after getting up on an empty stomach. On days when you are exercising, you should take it about 30 minutes before your workout.

The dosage for sport is between 2000-5000mg, depending on the intensity of the training. There is no limit to the duration of intake. Long-term use has proven to be beneficial in the case of prolonged exposure. For training, L-arginine can be mixed into a pre-workout shake or taken with sufficient liquid.So that the desired effects can be achieved with L-arginine and it can work as a supplement, it is important to adhere to a precise intake schedule, which is regularly monitored. In this way, over- or undersupply can be excluded and the dose can be adjusted if necessary.


The dosage of L-arginine depends on the respective application. For therapeutic measures, a daily dose of L-arginine of at least 3000mg is recommended. Dosage recommendations for the various areas of application are listed below:

  • for muscle building, especially in combination with other amino acids 2000-5000mg per day

  • in erectile dysfunction and stimulation of sperm formation at least 3000mg per day, best in combination with pine extract, which additionally supports the effect of L-arginine

  • 3000mg per day when treating tinnitus

  • for hair loss 500mg per day in combination with other nutrients

  • 3000-5000mg per day in the treatment of atherosclerosis

When exactly the appropriate dose should be taken or whether it should be divided into several doses over the day should be discussed in advance with a doctor or other specialist and always depends on the individual health situation.

You might also be interested in this topic: Leucine or L-carnitine

Foods with arginine

L-arginine is found in large quantities in many foods. Nuts in particular are way ahead here. Below are some foods with the respective amount of L-arginine per 100g:

  • Chicken: 1400mg
  • Beef: 1540mg
  • Tuna: 1200mg
  • Shrimp: 1700mg
  • Hazelnuts: 2000mg
  • Peanuts: 3400mg
  • Soybeans: 2200mg
  • Oatmeal: 850mg
  • Fig: 90mg
  • Banana: 60mg
  • Kale: 300mg
  • Lentils: 2240mg
  • Milk: 120mg
  • Edam: 1030mg