L-Arginine

L-Arginine is another one of the 20 nonessential amino acids.  In this context, nonessential mean that your body already produces a sufficient amount of them in your body.  Common sources of l-arginine are poultry, seafood, dairy, and nuts.  L-arginine has been shown to have benefits of increased muscle mass, reduced risk of heart disease, improved immune function, and decreased blood pressure.1

Research

One study supported the claims that l-arginine helps increase muscle mass in swine2.  Another study3 showed that l-arginine helped to stimulate the secretion of the growth hormone, also aiding in the increase of muscle mass.  It is important to note that the amount used in the study was much higher than what you’re likely to find in a diet pill.

There is no research backing up claims that l-arginine is directly effective in weight loss.

Conclusion

With no clinical studies supporting the claims that l-arginine is effective in weight loss, we’re not able to recommend it as a proven diet pill ingredient.   Studies do suggest that it may aid in increased muscle mass, but more research is needed to be definitive in that area as well.  For now, thumbs down for l-arginine.

  1. http://en.wikipedia.org/wiki/L-arginine [↩]
  2. Amino Acids, e-publication, Aug 6, 2008 [↩]
  3. Journal of Clinical Endocrinology and Metabolism, 67(6), 1186-1189 [↩]