Side effects of alpha lipoic acid may include headache, tingling or a "pins and needles" sensation, skin rash, or muscle cramps.
There have been a few reports in Japan of a rare condition called insulin autoimmune syndrome in people using alpha lipoic acid. The condition causes hypoglycemia and antibodies directed against the body's own insulin without previous insulin therapy.
The safety of alpha lipoic acid in pregnant or nursing women, children, or people with kidney or liver disease is unknown.
Possible Drug Interactions
Alpha lipoic acid may improve blood sugar control, so people with diabetes who are taking medication to lower blood sugar, such as metformin (Glucophage), glyburide (DiaBeta, Glynase), should only take alpha lipoic acid under the supervision of a qualified health professional and have their blood sugar levels carefully monitored.
Animal studies indicate that alpha lipoic acid may alter thyroid hormone levels, so it could theoretically have the same effect in humans. People taking thyroid medications such as levothyroxine should be monitored by their healthcare provider.