Categorisation | Drug | Routes of administration | Clinical applications | Effects on the endometrium | Other adverse reactions | |
Oestrogen | Natural oestrogen | 17β-E2 | Oral, transdermal or vaginal administration | Premenstrual syndrome Perimenopause syndrome Osteoporosis Premature ovarian insufficiency Amenorrhoea Dysfunctional uterine bleeding Prostate cancer Postmenopausal advanced breast cancer Alzheimer Acne | Endometrial hyperplasia Endometrial cancer (prolonged unopposed oestrogen exposure)30 | Gastrointestinal reactions, water and sodium retention, thromboembolism, etc |
Estriol | ||||||
CEE | ||||||
Synthetic oestrogen | Ethinylestradiol | Oral | ||||
Nilestradiol | ||||||
Phytoestrogen | Isoflavone | Oral | Perimenopause syndrome Obesity Hyperglycaemia Osteoporosis Oxidative stress52 | No endometrial cancer risk35 Uterine fibroids in premenopausal women36 | Suppresses thyroid function (controversial)53 | |
Oestrogen-related regulator | SERM | Tamoxifen | Oral | Breast cancer | Weak oestrogen-like effect Endometrial hyperplasia Endometrial cancer54 | Gastrointestinal reactions, visual disturbances, hair loss, etc |
Bazedoxifene | Oral | Postmenopausal osteoporosis | Oestrogen antagonist Protecting against E2-induced endometrial hyperplasia9 | Rarely55 | ||
STEAR | Tibolone | Oral | Perimenopause syndrome Vasomotor symptoms (including hot flushes and night sweats) Anxiety and/or depression Urogenital atrophy Osteoporosis Sexual dysfunction | Exerting its progestational effects primarily through the Δ4-isomer9 | Gastrointestinal reactions, allergic reactions, increasing recurrent breast cancer rates, increasing stroke rates56 | |
AI | Letrozole | Oral | Breast cancer Male infertility Female infertility | Endometrial protection Reducing the risk of recurrent endometrial cancer43 | Bone and joint pain, muscle pain and fatigue |
AI, aromatase inhibitor; CEE, conjugated equine estrogen; E2, estradiol; SERM, selective estrogen receptor modulator; STEAR, selective tissue estrogenic activity regulator.