Prolonged Estradiol Persistence and Possible Symptom-Biomarker Dissociation During Sequential Estradiol Implant Therapy in a Postmenopausal Woman: A Case Report

Subcutaneous estradiol implants are a long-acting modality of menopausal hormone therapy whose behavior during sequential implantations remains poorly characterized.We report a 52-year-old woman with natural menopause at the age of 48 years, who was followed for 45 months during five sequential 25 mg estradiol implants combined with gestrinone.Testosterone 50 mg was added from the fourth implantation due to low sexual desire.Estradiol concentrations remained measurable at all assessed post-implantation time points, ranging from 56 to 156 pg/mL.Gonadotropin fluctuations and late recurrence of vasomotor symptoms were observed despite persistent estradiol exposure.Reimplantation decisions were guided by clinical assessment integrated with serial hormonal monitoring rather than fixed intervals.Endometrial protection with dydrogesterone was maintained, and no adverse events were observed or reported.This case illustrates prolonged estradiol persistence, gonadotropin variability, and possible symptom-biomarker dissociation during sequential implant therapy, reinforcing the need for an individualized approach that integrates symptoms, hormone levels, and endometrial assessment.