L-arginine is the L-isomer of arginine and is an L-alpha-amino acid.

Arginine is an alpha-amino acid, one of the 8 essential amino acids in the human body. It is involved in protein synthesis and helps hormones maintain a healthy body and skin, and is involved in biological processes of the immune, cardiovascular and growth systems.

Synthesised, it appears as a white crystalline powder that is easily soluble in water, slightly soluble in ethanol, insoluble in ether, darkens in colour at 230°C, disintegrates at 244°C.

What it is used for and where

Medical

In ageing, growth hormones tend to work less and this results in less flexible and thinner skin. One remedy is injections of appropriate hormones, but this method is obviously quite different from what nature intended. An alternative and more natural remedy is to take a 'releaser', i.e. a component that has the function of stimulating the growth hormone: Arginine.

With regard to the cardiovascular system, this study highlights recent advances in the biological and clinical role of arginine, concluding that arginine may exert cardioprotective effects (1), and other studies point to its role in restoring endothelial function in atherosclerotic patients, in whom there are elevated levels of asymmetric dimethylarginine, thus the results confirm L-arginine as a potential therapy for cardiovascular disorders (2). Its use in hospitalised septic and critical patients has been controversial although the use of arginine has been shown to help a variety of critically ill patients (3).

In dental care many studies have focused on the effectiveness of arginine included in dental care products (toothpastes, mouthwashes) in preventing the development of new caries and the progression of existing caries, but the conclusions are mixed. Some believe that there is currently insufficient evidence to support a caries-preventive effect of the inclusion of arginine in these products (4), while other studies believe, albeit with very few well-conducted randomised controlled trials, that 1.5 per cent arginine and 1,450 ppm fluoride is effective in inactivating root caries lesions (5).

Arginine has proven to be of great help in wound healing and skin repair. 

Shockwave therapy or oral L-arginine therapy improved erectile dysfunction (6).

Cosmetics

Studies on arginine in the medical sector concerning its use as a tissue regenerator have led personal care cosmetics companies to include arginine in many creams and various preparations with the function of tissue regeneration, rejuvenation, elasticity and skin defence (7).

Safety

Arginine is generally considered to be a safe component in the scientific literature, however this recent study by researchers at the University of São Paulo, Brazil warns of the effects that may affect blood pressure and others caused by antiseptic mouthwashes containing chlorhexidine on L-arginine supplementation (8).

For more information:

Arginine studies

Typical commercial product characteristics L-arginine

Appearance	White powder
pH	10.5~12.0
Boiling Point	367.6±52.0°C at 760 mmHg
Melting Point	222°C
Flash Point	176.1±30.7°C
Vapor Pressure	0.0±1.8 mmHg at 25°C
Refraction Index	1.601
PSA	125.22000
LogP	-1.79
Water Solubility	148.7 g/L
Loss on drying	≤0.5%
Residue on ignition	≤0.1%
Chloride	≤0.02%
Sulfate	≤0.02%
Other amino acids	≤0.4%
Ammonium	≤0.02%
Arsenic	≤1ppm
Iron	≤10ppm
Heavy metals	≤10ppm
Chemical Risk

• Molecular Formula    C₆H₁₄N₄O₂
• Linear Formula     H₂NC(=NH)NH(CH₂)₃CH(NH₂)CO₂H
• Peso molecolare   174.204 g/mol
• Exact Mass    174.111679
• CAS   74-79-3  
• EC Number    200-811-1
• UNIII    94ZLA3W45F
• DSSTox Substance ID  DTXSID6041056
• IUPAC  (2S)-2-amino-5-(diaminomethylideneamino)pentanoic acid
• InChl=1S/C6H14N4O2/c7-4(5(11)12)2-1-3-10-6(8)9/h4H,1-3,7H2,(H,11,12)(H4,8,9,10)/t4-/m0/s1
• InChl Key      ODKSFYDXXFIFQN-BYPYZUCNSA-N
• SMILES   C(CC(C(=O)O)N)CN=C(N)N
• MDL number  MFCD00002635
• PubChem Substance ID    24278014
• Beilstein    1725413
• eCl@ss    32160406
• ChEBI  16467
• RTECS  CF1934200
• NCI    C62008
• FEMA    3819
• JECFA    1438    
• RXCUI    1091
• FEMA     3819

Price

100 g          $72.80

1 kg            $550.00

Synonyms: 

• L-(+)-Arginine
• L-arginine
• L(+)-Arginine
• L-Arginin
• L-Arg
• Polyarginine
• (S)-2-Amino-5-guanidinopentanoic acid
• Argamine
• H-Arg-OH
• Argivene
• (L)-Arginine
• Detoxargin

References________________________________________________________________

(1) Mangoni AA, Rodionov RN, McEvoy M, Zinellu A, Carru C, Sotgia S. New horizons in arginine metabolism, ageing and chronic disease states. Age Ageing. 2019 Nov 1;48(6):776-782. doi: 10.1093/ageing/afz083. 

(2) Gornik HL, Creager MA. Arginine and endothelial and vascular health. J Nutr. 2004 Oct;134(10 Suppl):2880S-2887S; discussion 2895S. doi: 10.1093/jn/134.10.2880S. 

(3) Rosenthal MD, Carrott PW, Patel J, Kiraly L, Martindale RG. Parenteral or Enteral Arginine Supplementation Safety and Efficacy. J Nutr. 2016 Dec;146(12):2594S-2600S. doi: 10.3945/jn.115.228544. 

(4) Ástvaldsdóttir Á, Naimi-Akbar A, Davidson T, Brolund A, Lintamo L, Attergren Granath A, Tranæus S, Östlund P. Arginine and Caries Prevention: A Systematic Review. Caries Res. 2016;50(4):383-93. doi: 10.1159/000446249.

(5) Wierichs RJ, Meyer-Lueckel H. Systematic review on noninvasive treatment of root caries lesions. J Dent Res. 2015 Feb;94(2):261-71. doi: 10.1177/0022034514557330. 

(6) Gallo L, Pecoraro S, Sarnacchiaro P. Adjuvant daily therapy with L-arginine 2,500 mg and tadalafil 5 mg increases efficacy and duration of benefits of low-intensity extracorporeal shock wave therapy for erectile dysfunction: A prospective, randomized, single-blinded study with 1-year follow-up. Investig Clin Urol. 2022 Jan;63(1):83-91. doi: 10.4111/icu.20210317.

(7) Kocic H, Arsic I, Stankovic M, Tiodorovic D, Ciric V, Kocic G. Proliferative, anti-apoptotic and immune-enhancing effects of L-arginine in culture of skin fibroblasts. J Biol Regul Homeost Agents. 2017 Jul-Sep;31(3):667-672.

(8) Batista RIM, Nogueira RC, Ferreira GC, Oliveira-Paula GH, Damacena-Angelis C, Pinheiro LC, Tanus-Santos JE. Antiseptic mouthwash inhibits antihypertensive and vascular protective effects of L-arginine. Eur J Pharmacol. 2021 Sep 15;907:174314. doi: 10.1016/j.ejphar.2021.174314.