“ …St John's wort was associated with a significant (P <.05) increase in the oral clearance of norethindrone (8.2 +/- 2.… 9.5 +/- 3.4 L/h, P =.042) and a significant reduction in the half-life of ethinyl estradiol (23.4 +/- 19.5 hours ….1 hours, P =.023).”