Alpha-Lipoic Acid (ALA) has scientific validation for use in certain types of neuralgia and neuritis, particularly diabetic neuropathy. Multiple randomized, double-blind, placebo-controlled trials have demonstrated that intravenous and oral administration of ALA can significantly reduce neuropathic symptoms such as pain, burning, and numbness in patients with diabetic polyneuropathy. The most robust evidence comes from studies involving intravenous ALA (typically 600 mg/day), which show moderate-to-large improvements in neuropathic symptoms after 3 weeks of treatment. Oral ALA has also been studied, with somewhat less pronounced but still significant benefits over several months of use.

Mechanistically, ALA is a potent antioxidant. It is thought to alleviate neuralgia and neuritis by reducing oxidative stress, regenerating other antioxidants, and improving nerve blood flow. These effects may help protect nerve tissues from damage associated with chronic high blood sugar or other metabolic insults.

Most guidelines and meta-analyses, such as those published in Diabetes Care and by the American Academy of Neurology, consider ALA an evidence-based adjunctive treatment for diabetic neuropathy. However, evidence for other causes of neuralgia or neuritis (e.g., postherpetic neuralgia, mechanical nerve injury) is much weaker or lacking. Importantly, ALA is not a cure, and its effects are mainly symptomatic and adjunctive to other therapies.