We observed a non-significant inverse association between dysmenorrhea frequency and IL-6 levels among the cases (GM for often/usually of 2.12 with 95% CI of 1.67–2.68 vs. GM for always of 1.55 with 95% CI of 1.40–1.73; p-trend = 0.07) with a significant interaction with case–control status (p-interaction = 0.01), as no association was observed among the controls (p-trend = 0.11; Figure 2; Table S3). Here, IL6 is linked to Dysmenorrhea.