According to the findings of a randomized clinical trial, oral administration of alpha-lipoic acid food supplement for two months at doses of 400 mg/day or 800 mg/day was effective to minimize pain with unknown etiology (idiopathic pain) in normoglycemic adults. In this monocentric, placebo-controlled, double-blind study, Cristina Esposito et al. aimed to determine the efficacy and safety of alpha-lipoic acid food supplementation to alleviate the various forms of idiopathic pain.

The study recruited 210 normoglycemic people suffering from idiopathic pain (57 people having primitive neuropathic pain, 141 people having arthralgia with unknown etiology, and 12 people having idiopathic myalgia). Participants were randomly allocated to receive 800 mg/day alpha-lipoic acid (Group 1, n=70), 400 mg/day alpha-lipoic acid (Group 2, n=70) and placebo (Group 3, n=70).

They underwent two visits (at baseline [t0] and after two months [t1]) during which collection of 2 validated questionaries for pain (numerical rating scale [NRS] and visual analogue scale [VAS]) was done. Monitoring of fasting blood glucose, side effects, and kidney and liver toxicity was also done.

At t1, none of the alpha-lipoic acid recipients experienced reduced glycemia or adverse effects. Alpha-lipoic acid recipients witnessed a considerable decline in NRS. On the other hand, the placebo recipients did not witness any decline in NRS. Regarding VAS, similar outcomes were procured, as illustrated in Table 1:

The statistical assessment aimed at exploring possible differences in NRS and VAS scores among study groups based on the source of pain did not show any profound effect. Thus, oral supplementation with alpha-lipoic acid is effective and safe to alleviate idiopathic pain.