90 women participated in a 4-month study. During the first 2 periods, they took no
pain relievers whatsoever; during their last 2 periods they took 2 X 325 mg
aspirin,
acetaminophen or an identically packaged placebo every 4 h to total 8
tablets during the first 24 h of their periods beginning with
spotting. For statistical analysis, periods 1 and 2 were combined and averaged, then compared with periods 3 and 4 combined and averaged. Total menstrual loss in grams, number of days of flow, and
pain of
cramps and
headaches were analyzed by MANOVA for each of the three treatment groups. An ANOVA for each of these variables as well as for daily menstrual loss for the first 3 menstrual days was also performed. The MANOVA for all variables by the three treatment groups failed to show any significant differences. Similarly, ANOVAs for the individual variables failed to indicate significant differences except for the variable
pain of
cramps (p = 0.0072). The Duncan's Multiple Range Test for
pain of
cramps showed that the average
pain for the placebo group was higher than for either the
aspirin or the
acetaminophen group, although the means for these two groups were not significantly different. These results indicate that neither
aspirin nor
acetaminophen in the doses given alter either total menstrual loss or the pattern of loss during the first 3 menstrual days. However, both preparations were found to be more effective than placebo in reducing
pain of
cramps.