In one study, 40 women recently diagnosed with SH took alpha-lipoic acid or a placebo daily for three weeks. While there were no changes for the placebo group, those in the alpha-lipoic acid group had much lower levels of oxidative stress and greater blood-vessel flexibility compared to placebo and compared to the beginning of the study. Researchers also found a direct link: as levels of oxidative stress decreased, blood-vessel flexibility increased.