Arginine or L-arginine is a semi-essential amino acid that is used in the biosynthesis of proteins. (Tapiero H et al., 2002)
Arginine is used to improve circulation, improve the immune system and some research suggests that it can be beneficial for patients with heart failure (Rector et al., 1996) and small-vessel coronary endothelial function in humans. (Lerman et al., 1998)
Why are these things important in hair growth?
- Hair keratin can only grow if it receives amino acids and other nutrients via the blood stream. Treatments like Minoxidil, which increase blood flow to the scalp work for this reason. But we can use amino acids like arginine to achieve similar results as well as gaining several other benefits, without negative side effects.
- Keratin is a protein, which is synthesized from amino acids such as cysteine, lysine and methionine. Arginine aids in the synthesis of proteins and therefore should help increase the development of hair keratin.
Other studies suggest that arginine also accelerates wound healing (Barbul et al., 1990; Stechmiller et al., 2005) helps with fat burning, enhances skeletal muscle (Jobgen et. al, 2009) and decreases the cholesterol induced atherosclerosis.(Hayashi et al., 2005) Even more research suggests that arginine improves libido in men as well as their sexual performance. (Klotz et al., 1999)
Nitric oxide and hair growth
A number of studies have shown that arginine has vasodilating effects; these effects might help with hair growth as a precursor of nitric oxide. (Bode-Böger et al., 1998;1996) Due to this vasodilating effect arginine can be considered to be one of the amino-acids that might promote hair growth, either through oral supplements or even topical application.
Arginine’s role in hair growth
To better understand the role of arginine in hair growth, let’s take the hair fibre, which is extremely sensitive to stimulatory and inhibitory signals.
There is a wide array of modulators in the hair follicle, from cytokines, neuropeptides, hormones, prostaglandins and growth factors, all of which contribute to its modification. There is a strict dependence for arginine as well as polyamines, glucose for growth and a particular immunological response. (Bernard, 2016)
A number of studies suggest that there is a connection between lack of arginine and hair loss
A 2004 study (Oshimura and Ino) showed potential benefits of arginine for hair, even when the hair is exposed to harmful agents such as colouring solutions or a bleaching process. Arginine was added to the colouring solution containing hydrogen peroxide and ammonia.
Hair that underwent colouring with arginine enhanced solutions was less damaged and contained substantial arginine deposits added to the hair follicle by the colouring agents.
Arginine for hair loss
A number of studies suggest that there is a connection between lack of arginine and hair loss. A study on intestinal arginine production for neonatal development concluded that arginine deficiency is correlated with a degree of retardation in hair and muscle growth as well as the development of the lymphoid tissue. However, some of the abnormalities were reversed with the help of arginine injections. (de Jonge, 2002)
A study from 2011 on mice with an overexpression of arginase showed that they develop hypoarginiemia along with reduced hair and muscle growth as well as impaired B-cell maturation. (Marion et al., 2011)
It seems that arginine increases hair growth
Another study from 2012 (Sreenath et al.) on argininosuccinate lyase deficiency also shows the benefits of arginine. This condition is the second most common urea cycle disorder and, among other symptoms, manifests itself through trichorrexis nodosa, creating nodular swellings of the hair shaft that comes with loss of cuticle and frayed hair fibers. People who have argininosuccinate lyase deficiency will experience symptoms like brittle hair, thinning hair and ultimately partial alopecia according to another paper cited in the study. (FIchtel, Richards & Davis, 2007)
It seems that 10.5% arginine is found in normal hair and anything less than that leads to a weakened hair follicle and breakage. (Marion et al., 2011)
Furthermore, the paper concludes that supplementation with arginine of 400-700mg per kg/day might prove successful in helping individuals with argininosuccinate lyase deficiency in reversing the hair changes. However, no further studies or follow-ups have been made so the researchers are not yet sure of its possible harmful long term effects.
The results were spectacular: the in vitro hair that was not treated with arginine stopped elongating while the one treated with arginine increased in size
A study that might potentially change the whole way we see hair loss was conducted in 2014, researching the importance of arginine in human hair elongation. (Michelet et al.) The study argues that besides hair transplantation or topical minoxidil application, there may be ways to counteract hair loss by taking into account the hair follicle and what changes its structure.
Scientists studied L-arginine concentration on in vitro human hair and showed that the amino acid had a clear anti-hair-loss effect. It seems that arginine increases hair growth, making it possible for scientists to further research a solution for those who suffer for various forms of alopecia.
Human hair follicles were treated with L-Arginine for 3 days / 12 days with renewal of culture medium and another treatment every 2 days. The in-vivo evaluation analysed 63 healthy male subjects aged 18 to 55 with androgenic alopecia from III to V grade. The effects were established using the phototrichogram technique.
33 of the subjects received a lotion containing L-Arginine while 30 of them received a placebo. The effects were measured for 1.5 months. The results were spectacular: the in vitro hair that was not treated with arginine stopped elongating while the one treated with arginine increased in size. For the in vivo studies, there was a clear improvement for the group that used the L-Arginine lotion as they showed an increase of anagen hair density and decrease of telogen hair rate, which is a resting status of the hair follicle.
It is clear that the anti-aging effects of L-Arginine along with the studies done on its effects on hair loss allow scientists to come up with new research paths for treating or preventing alopecia. Arginine is a versatile amino acid and its anti-aging potential is higher than other pharmaceutical or nutraceutical agents. (Gad, 2009)
Since the long term effects of arginine supplementation are yet to be researched, people who want to benefit from this amino acid can still try by adding it naturally in their diet.
According to Nutritiondata website some of the highest arginine containing foods are the following:
- sesame seeds
- soy protein
- shrimp, crab, crayfish, lobster
- some types of game meat (moose, elk)
People can easily introduce these foods into their diets and get the benefits from arginine supplementation without being exposed to the possible long term medication risks.
The question still remains whether arginine is better applied topical or orally ingested. However, the studies presented in this article show that whatever the form of treatment is used, arginine does impact hair growth.
Read nextWhats the best shampoo for hair loss?
How to use arginine for hair growth
To use arginine to increase hair growth you simply have to consume a combination of natural ingredients. A special combination of ingredients increase arginine and nitric oxide in your blood. They also increase protein synthesis and promote cell production in the scalp.
To learn how I use arginine and several other amino acids as part of my hair growth smoothies, download my eBook.
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- Thomas S. Rector, Alan J. Bank, Kathleen A. Mullen, Linda K. Tschumperlin, Ronald Sih, Kamalesh Pillai, and Spencer H. Kubo, Randomized, Double-Blind, Placebo-Controlled Study of Supplemental Oral L-Arginine in Patients With Heart Failure, 1996;93:2135-2141, doi:10.1161/01.CIR.93.12.2135 Link: http://www.ncbi.nlm.nih.gov/pubmed/8925582?dopt=Abstract
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