BACKGROUND: Burning mouth syndrome (BMS) has features of a neuropathy and could 
be related to the production of the toxic free radicals that are released in 
stress situations. Alpha-lipoic acid is an antioxidant able to increase the 
levels of intracellular glutathione and eliminate free radicals. This study 
aimed to examine the effectiveness of alpha-lipoic acid in the therapy of BMS.
METHOD: This was a double blind, controlled study conducted for two months on 60 
patients with constant BMS. Comparing alpha-lipoic acid (test) with cellulose 
starch (placebo), there was no laboratory evidence of deficiencies in iron, 
vitamins or thyroid function and no hyperglycaemia.
RESULTS AND CONCLUSION: Following treatment with alpha-lipoic acid, there was a 
significant symptomatic improvement, compared with placebo, with the majority 
showing at least some improvement after 2 months, thus supporting the hypothesis 
that burning mouth syndrome is a neuropathy. This improvement was maintained in 
over 70% of patients at the 1 year follow-up.