L-Arginine
L-Arginine took the supplement industry by storm in the mid-1990s with the introduction of the “pre-workout” product category. Arginine was marketed as a nitric oxide booster, which it is still extremely popular today.
Over the past 5-10 years, emerging science has cast some doubt as to the effectiveness of arginine in regards to producing “skin tearing” pumps like so many companies claimed it to, yet there is still solid evidence of arginine having numerous benefits for athletes and every day users.
What it does
Arginine is best known for its purported ability to increase nitric oxide, thereby allowing it to be effective for both pre-workout pump benefits along with “male enhancement” style products.
Studies have shown arginine to be able to provide enhanced blood flow/increased nitric oxide[1][2], while similar studies have shown no ability to raise nitric oxide[3][4].
Arginine has been shown to increase peak growth hormone concentrations[5], and help moderate mild to moderate erectile dysfunction in men[6].
How it works
Arginine works through its theoretical ability to increase plasma arginine concentrations in the blood. The use of the word “theoretically” is provided here due to the obvious contradiction in studies showing this to be both true and false.
Arginine is mostly broken down in the gut during digestion and is further acted upon by the arginase enzyme, rendering the vast majority of orally consumed arginine useless. The proposed difference in study results is due to these facts, leading many to believe that arginine metabolizes at varying degrees based on the individual. Simply put, while it may work for some, it will not work for all.
Dosing
To get the advertised benefits of arginine, the suggested daily dose is a minimum of 6g[7]. Most dietary supplements including arginine offer far less than this in a daily serving.
References
- https://www.ncbi.nlm.nih.gov/pubmed/17662090
- http://jap.physiology.org/content/early/2010/08/19/japplphysiol.00503.2010
- http://www.ncbi.nlm.nih.gov/pubmed/18708287
- http://www.ncbi.nlm.nih.gov/pubmed/21813912
- https://www.ncbi.nlm.nih.gov/pubmed/15809017
- https://www.ncbi.nlm.nih.gov/pubmed/26428638
- http://jap.physiology.org/content/early/2010/08/19/japplphysiol.00503.2010