LHRH analogues (LHRHa) are used in the treatment of breast cancer that occurs in young women. Amenorrhoea induced by chemotherapy correlates with a reduced risk of recurrence disease. In premenopausal women, analogous LHRHs are used to suppress ovarian estrogen production, raising estrogen hormone levels to post-menopausal values and improving patient outcomes. Two large clinical studies have investigated the role of complete estrogen blockage in adjuvant hormonal treatment of premenopausal patients. Both studies showed the clinical benefit of ovarian suppression treatment, mainly associated with non-steroidal aromatase inhibitor exemestane in high-risk patients. In the recent years, hormonal treatments made available in clinical practice have considerably prolonged the median survival of patients suffering from endocrine-responsive metastatic breast cancer. Even in the premenopausal setting, CDK4/6 inhibitors in association with endocrine therapy have shown a marked improvement in patient outcomes. The safety and efficacy of this new class of drugs demonstrated in the MONALEESA-7 study in premenopausal women and in the premenopausal subgroups of the PALOMA-3 and MONARCH 2 studies support the use of hormone therapy and analogous LHRH combined with CDK 4/6 inhibitor in patients in premenopausal. Finally, LHRH analogues have been extensively studied in strategies for maintaining ovarian function and fertility preservation during adjuvant chemotherapy in younger patients.