Since this thread mentions l-arginine... I found this yesterday on the net:

http://www.drignarro.com/notestimonials.php

http://www.drignarro.com/press.php

His claim is that using l-arginine and l-citruline can increase nitric oxide in blood vessels, and lead to improved circulation, and less oxidative damage. (his mixture has also lowered blood pressure).
Here is an independent paper on this subject:
http://www.pubmedcentral.nih.gov/art...?artid=2291275

And to Sandra--- Biofreeze is not "cold". It is a gel with Ilex in it and menthol. It reduces burning sensations from nerves in the periphery. It is commonly used in physical therapy which is where I found it. Some therapists mix it 1/2 and 1/2 with the ultrasound lubricant, when the ultrasound treatments are done.
Ilex is an herb also called Yerba Mate, which is a tea from S. America, used there more than coffee socially. It is very high in antioxidant value, and I believe it is really the most important ingredient in Biofreeze. Our FDA however, makes them list it as an inert ingredient, because of the "rules" of drug claims we have here.

Patients with cold intolerance RSD may not like the cool feeling. But I don't believe the gel itself changes any temperature in the skin. Biofreeze is more likely to be acceptable to those with hot burning RSD...which more resembles PN. Many of us PNers find it very comforting when nothing else will stop burning that goes on all night!