Arginine: Are there dangers to be aware of and precautions to take?

Arginine is one of the amino acids that make up proteins. It was first isolated in 1886 from a plant, the yellow lupin, by the German chemist Ernst SCHULZE and his assistant Ernst STEIGER. Arginine derives its name from the Greek árgyros, which means "silver", due to the silvery white appearance of arginine nitrate crystals. This naturally occurring amino acid found in the body is involved in various biological processes such as the regulation of cell division, facilitating the healing process, and the proper functioning of the immune function.

Arginine is typically offered as a dietary supplement, in solid, liquid, or powder form. Favoured by athletes, it is believed to have an effect on muscle work and recovery. However, studies on the subject report moderate and variable results depending on the training regimen. The arginine can also be incorporated into cosmetic treatments and used for its hydrating properties for the skin and strengthening effects on the hair, eyelashes or eyebrows.

Before starting a supplementation, it is important to discuss it with one's doctor.

The intake of dietary supplements is not harmless and can pose health risks. Arginine is no exception to this rule and its oral consumption is regulated and is not suitable for everyone as it can lead to undesirable side effects. Therefore, people who have had a heart attack, those suffering from liver cirrhosis and those with asthma are not encouraged to take arginine.

Side effects associated with arginine are, however, relatively infrequent and of a benign nature. These primarily include headaches, digestive disorders, and diarrhoea. To avoid these, it is imperative to adhere to the doses recommended by suppliers, generally ranging between 8 and 12 g. It should be noted that studies conducted on the potential dangers of arginine supplementation have shown an absence of side effects for daily doses not exceeding 30 g. Furthermore, studies carried out on pregnant women, a potentially more vulnerable population, have also not raised any safety issues. On the contrary, arginine supplementation could reduce the risks of pre-eclampsia and eclampsia.

Important : However, please be cautious if you are pregnant and considering starting an arginine regimen. The women who participated in the studies were medically monitored throughout the process. Do not start an arginine supplement without first discussing it with your doctor.

Arginine is a safe and non-irritating amino acid whose concentration in cosmetic products is not explicitly restricted by European cosmetic regulations. This is based on the Regulation (EC) No 1223/2009 which sets out the requirements that cosmetic products must meet. These include safety, labelling, product composition, good manufacturing practices, as well as product notification and the obligations of manufacturers and distributors.

Arginine is, however, used at doses ranging between 0.5 and 5% as a cosmetic active ingredient, a higher concentration does not provide additional benefits. Moreover, its topical use is not limited to certain population groups or certain skin types, and pregnant or breastfeeding women, young children, or even people with sensitive skin can apply a treatment formulated with this active ingredient.

• Regulation (EC) No 1223/2009 of the European Parliament and the Council.

• GRIMBLE G. K. Negative Gastrointestinal Impacts of Arginine and Associated Amino Acids. The Journal of Nutrition (2007).

• SUREDA A. & PONS A. Arginine and Citrulline Supplementation in Sports and Exercise: Performance Enhancing Nutrients? Current Topics in Sports Nutrition (2013).

• ZHOU R. & al. Arginine supplementation for enhancing maternal and neonatal outcomes in hypertensive disorder of pregnancy: a systematic review. Journal of the renin-angiotensin-aldosterone system: JRAAS (2014).

• MESHRAM A. & SRIVASTAVA N. Diverse potential and pharmacological studies of arginine. Journal of Proteins and Proteomics (2015).

• WU G. & al. Safety and Efficacy of Arginine in Adults. The Journal of Nutrition (2016).