The purpose of this article was to comprehensively review and evaluate the safety and efficacy of bio-identical hormones in the management of menopausal symptoms. Some of the studies reviewed involved both bio-identical estrogens and progesterone and they were found to be effective in tackling menopausal symptoms and were associated with a reduced risk of blood clots compared to synthetic hormone therapy. One study involving 3,175 post-menopausal women predominantly using natural hormone therapy found there was no increased risk of breast cancer compared with conventional HRT. A second cohort study with 54,548 post-menopausal women found the risk of breast cancer to be significantly greater with HRT involving synthetic hormones versus HRT with bio-identical hormones. These large cohort studies assessing the safety of bio-identical hormones provide significant evidence to support the safety of bio-identical HRT with respect to breast tissue.