PURPOSE: To evaluate the impact of an interleukin-1 (IL-1) antagonist anakinra (Kineret®) on endometriosis-related quality of life (QoL), pain, and inflammatory biomarkers. METHODS: This was a single-site, randomized, double-blinded, placebo-controlled, cross-over pilot clinical study of patients recruited at an academic specialty clinic. Eligible participants were females aged 18-45 years with menstrual cycles every 24-32 days. Subjects had moderate to severe dysmenorrhea and either a surgical diagnosis of endometriosis or an endometrioma on imaging. Subjects were randomly assigned in a double-blind fashion to receive either the study drug or placebo administered as daily injections during the first 3 periods and then the alternate intervention for the next 3 periods. RESULTS: Fifteen subjects completed the 6 menstrual cycle study. After each period, they completed the Endometriosis Health Profile-30 (EHP-30) QoL questionnaire and an assessment of dysmenorrhea using a 0-100 Visual Analogue Scale (VAS). All domains of the EHP-30 showed a trend towards improvement, with significant improvements in powerlessness (54.5 vs 63.3, p = 0.04) and self-image (58.1 vs 66.7, p = 0.03) on the study drug compared to placebo. The mean dysmenorrhea VAS also trended toward improvement with a score of 37.5 during active treatment and 42.6 with placebo (p = 0.26). No difference in menstrual cycle length was detected (29.3 days vs 27.7 days, p = 0.56). There were significant differences in multiple inflammatory biomarkers between the study drug and placebo, including BDNF, IL-1, and IL-6 among certain groups. CONCLUSION: With all EHP-30 domains and the dysmenorrhea VAS showing either a statistical improvement or trend towards improvement, there is justification for a larger study. As no impact on menstrual cycles was detected, anakinra may be a particularly impactful option for women desiring fertility. Additional evaluation is needed on the role of anakinra on inflammatory markers given significant reductions were identified in multiple biomarkers.