Lipoic Acid has a variety of benefits:

Antioxidant
Lipoic acid can regenerate vitamin C from its oxidized form, dehydroascorbic acid. Lipoic acid can also potentially regenerate other antioxidants. Lipoic acid increases the levels of glutathione, a very important antioxidant normally found in our cells and responsible for mopping up all types of toxins and free radicals. Glutathione supplements, however, are not helpful since glutathione does not have the ability to cross cell membranes. Fortunately, both laboratory and animal studies have shown that lipoic acid can stimulate the production of this antioxidant. This is particularly important during periods of excessive stress or exposure to radiation or toxic substances.

Lipoic acid also acts as a powerful antioxidant in the brain and is likely to protect brain cells from toxins.

Burning Mouth Syndrome
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. A study conducted for two months on 60 patients with constant BMS showed treatment with alpha-lipoic acid significantly improved symptoms compared to placebo. This improvement was maintained in over 70% of patients at the 1 year follow-up.

Diabetes
Lipoic acid is helpful in diabetics, including those with diabetic neuropathy and diabetic nephropathy (kidney disease). Oxidative stress plays a central role in the pathogenesis and progression of late microangiopathic (small vessel) complications in diabetes mellitus. Treatment of diabetic patients with the lipoic acid reduces oxidative stress and urinary albumin excretion, and slows the progression of endothelial cell damage. The dose for diabetics may range from 50 to 300 mg daily.

Diabetic Neuropathy
High blood sugar levels for prolonged periods can be toxic to nerves in the body. Diabetics who don't control their blood sugar eventually start losing sensation in their feet. Other problems follow resulting from damage to various nerves that supply internal organs. Even impotence can result due to loss of nerve sensation in genital organs. However high blood sugar may not be the only culprit. Diabetics are usually under high oxidative stress and this probably contributes to their neurological problems.

Several studies indicate that lipoic acid has beneficial effects on diabetic neuropathy, party due to its actions as an antioxidant, and also by improving the circulation to tiny blood vessels supplying nerve tissue.

Erectile Dysfunction
Lipoic acid and gamma-linolenic acid interact synergistically to improve nitric oxide-mediated neurogenic and endothelium-dependent relaxation of corpus cavernosum in experimental diabetes. Whether lipoic acid helps those with sexual dysfunction is not known.