This paper presents the results from a randomized evaluation that distributed menstrual cups (menstrual sanitary products) to adolescent girls in rural Nepal. Girls in the study were randomly allocated a menstrual cup for use during their monthly period and were followed for fifteen months to measure the effects of having modern sanitary products on schooling. While girls were 3 percentage points less likely to attend school on days of their period, the researchers find no significant effect of being allocated a menstrual cup on school attendance. There were also no effects on test scores, self-reported measures of self-esteem or gynecological health. These results suggest that policy claims that barriers to girls' schooling and activities during menstrual periods are due to lack of modern sanitary protection may not be warranted. On the other hand, sanitary products are quickly and widely adopted by girls and are convenient in other ways, unrelated to short-term schooling gains.