We have also noted that 24-hour urinary estrogens can be a sensitive monitor of liver detoxification capability. Elevated urinary estrogens in normally-cycling women may indicate a history of exposure to liver stresses such as excessive environmental organic chemicals. Interventions intended to improve liver function result in a gradual normalization of the abnormal estrogen levels. Thus, measurement of urinary estrogens can give insight into other aspects of physiology. This phenomenon is also noted in peri- or post-menopausal women who have previously taken Premarin, and have switched to triple-estrogen replacement with less-than-optimal symptom relief.