Background: Breast cancer in Indonesia is reported to have reached 68,858 out of 396,914 new cases of cancer, with an incidence rate of 16.6% based on Globocan 2020 data. Complementary therapies are much sought after for psychological and economic reasons and have minimal side effects. Curcumin has anti-carcinogenic properties. IL-6 plays an important role in the growth and metastasis of breast cancer cells, renewal of breast cancer stem cells, and drug resistance in breast cancer stem cells. Methods: A randomized controlled trial with post-test only group design using artificial female Balb/c strain rats (Mus Musculus) with DMBA-induced mammary adenocarcinoma nodules were reported, rats were divided into four groups randomly, namely, Control (K), Treatment 1: turmeric extract dose 100mg/KgBW (P1), Treatment 2: turmeric extract dose 150mg/KgBW (P2), Treatment 3: turmeric extract dose 200mg/KgBW (P3). Variables under study were IL-6 expression. One Way Anova test, followed by the Post-hoc Test, was used to test the difference among and between groups. Results: The mean value of IL-6 expression in groups K (53,59 ± 8,37), P1 (50,66 ± 9,59), P2 (66,93 ± 9,64), P3 (64,58 ± 5,97). The Post-Hoc test showed significant differences in IL-6 expression from group K against P2 (p=0.038), group P1 against P2 (p=0.015), and P3 (p=0.040). Conclusion: Turmeric extract (Curcuma longa) had an effect on IL-6 expression in the control group and the treatment group.