The invention relates to the use of R-(+)-.alpha.-lipoic acid, R-(-)-dihydrolipoic acid or their metabolites, salts, esters and amides for the synthesis of drugs for the treatment of diabetes mellitus of types I and II, compensated and decompensated insulin resistance and sequelae or late complications of diabetes mellitus, such as cataracts, polyneuropathy, nephropathy, as well as sequelae or late complications of insulin resistance. These drugs mentioned can also be used advantageously in combination with other antidiabetic drugs, particularly with insulin, and/or other additives or stabilizers or adjuvants, such as vitamin B, vitamin C, NADH, NADPH and ubiquinone. The invention furthermore relates to the use of R-(+)-.alpha.-lipoic acid, R-(-)-dihydrolipoic acid or their metabolites, as well as their salts, esters and amides for the preparation of drugs for the treatment of diseases with limited function of or a lowered content of the glucose transporters.