Lipoic acid, from potatoes, is a helpful antioxidant which restores and supports function of other antioxidants (such as vitamin E) and also can help heal nerve pain (the latter at a dose of 300 mg 2 times a day).
Alpha lipoic acid is an antioxidant which has been shown to be especially beneficial for diabetic neuropathy. Another study showed that it was also helpful in relieving "burning mouth syndrome." This syndrome is characterized by chronic pain on the tongue and sometimes the anterior palate and lips without any visible lesions. It is most often seen in postmenopausal women and has characteristics of being neuropathic pain. In a study of 60 patients, half received 200 mg of lipoic acid 3 times a day or a placebo for 2 to 5 months. Ninety-seven percent of the patients improved as compared to 40 percent of those in the placebo group. Thirteen percent had complete resolution of their pain, and another 74 percent had "decided improvement," whereas none of the placebo patients had this level of improvement. Almost all the patients showed some improvement by 2 months, with 73 percent still showing benefit at the end of 12 months despite having stopped the treatment. The fact that lipoic acid helps in several kinds of neuropathies suggests it is worth trying in others as well, especially since it is quite benign and not very expensive.