BACKGROUND Adenomyosis, which involves the presence of endometrial tissue within the uterine muscle, leads to chronic pelvic pain and heavy menstrual bleeding, creating challenges for contraception. The subdermal contraceptive implant Implanon presents a potential solution due to its long-acting properties. This study evaluates the efficacy, safety, and user satisfaction of Implanon in patients with adenomyosis, aiming to enhance understanding of its clinical benefits in this demographic. MATERIAL AND METHODS A prospective study over three years at Qingdao Women and Children's Hospital followed 124 women with and without adenomyosis after they received Implanon implants. Follow-up visits at 10 days, 3 months, 6 months, 1 year, 2 years, and 3 years post-implantation assessed adverse events, implant removals, and patient satisfaction. A survival analysis was conducted to investigate the influence of adenomyosis on the continuation of the implant. RESULTS All 124 patients completed the study with a 100% follow-up and contraception rate. Bleeding disorders, excluding amenorrhea, were the most common adverse events, affecting 52.42% of participants at 3 months and decreasing to 8.43% at 36 months. The incidence was notably lower in those with adenomyosis, with a significant decline seen from 6 to 12 months after implantation. The implant continuation rates at 1 year, 2 years, and 3 years were 75.81%, 66.94% and 54.84%, respectively. Women with adenomyosis had a lower risk of removal (hazard ratio=0.62) and higher satisfaction and were more inclined to opt for reimplantation upon expiration. CONCLUSIONS Implanon is a relatively effective and safe contraceptive, particularly for women with adenomyosis. Counseling on possible bleeding-related side effects is crucial for maintaining satisfaction and optimizing implant use.