Overview of systemic MHT

Systemic menopausal hormone therapy (MHT) is indicated for:

treating symptoms of menopause—particularly vasomotor symptoms and sleep disturbance. It can reduce symptoms of vulvovaginal atrophy, but it is less effective than intravaginal estrogen. It may also have some benefit for mood in perimenopause
treating or preventing osteoporosis; see Other drugs for osteoporosis
preventing cardiovascular disease in individuals with premature ovarian insufficiency (POI) or early menopause.

Options for systemic MHT are:

estrogen-only MHT
combined MHT (estrogen plus progestogen) in a cyclical combined or continuous combined regimen (progestogen must be added to systemic estrogen in individuals with endometrial tissue)
other forms of systemic MHT—tibolone or conjugated estrogens+bazedoxifene (these are not suitable for perimenopausal individuals).

For menopausal individuals requiring contraception, a contraceptive can be used as part of MHT; see Approach to starting therapy for menopause for details.

Before starting systemic MHT, individualised assessment of the expected benefits and harms of treatment is needed.

See Approach to starting therapy for menopause for a guide to choosing initial treatment for menopause. Factors affecting choice of systemic MHT are:

menopausal stage (ie perimenopause or post menopause)
age of menopause (particularly premature ovarian insufficiency or early menopause)
need for contraception
indications or preferences for specific formulation (oral or transdermal estrogen, or oral, transdermal or intrauterine progestogen)
past experience of adverse effects
cost.

See Types of systemic menopausal hormone therapy and the appropriate subgroups of menopausal patients for a summary of the types of systemic MHT, and which subgroups of menopausal patients can be treated with each.

Table 1. Types of systemic menopausal hormone therapy and the appropriate subgroups of menopausal patients
Type of systemic MHT	Drugs used	Appropriate subgroup of menopausal patients
estrogen-only	estrogen continuously	only individuals who have had a total hysterectomy (because unopposed estrogen increases risk of endometrial cancer) [NB1]
cyclical combined	estrogen continuously with a progestogen for only 10 to 14 days of each cycle	individuals with endometrial tissue [NB2] who: are perimenopausal (ie had their last menstrual period less than 1 year ago) because breakthrough bleeding may occur with continuous MHT have premature ovarian insufficiency [NB3]
continuous combined	both estrogen and progestogen continuously	individuals with endometrial tissue [NB2] who: are postmenopausal (ie had their last period more than 1 year ago) have been taking cyclical combined MHT for the last year, and withdrawal bleeding is becoming lighter have premature ovarian insufficiency [NB3] have migraines [NB4]
other	conjugated estrogens+bazedoxifene	postmenopausal individuals (ie had their last period more than 1 year ago), as an alternative to combined MHT [NB5]
other	tibolone	postmenopausal individuals (ie had their last period more than 1 year ago), as an alternative to combined MHT [NB5]
Note: MHT = menopausal hormone therapy. NB1: For individuals who have had a total hysterectomy but have significant endometriosis, addition of a progestogen may be required to prevent stimulation of endometrial deposits and malignant transformation; seek specialist advice. NB2: Individuals with endometrial tissue require progestogen to reduce the risk of endometrial cancer with unopposed estrogen; this includes those who have an intact uterus, have had endometrial ablation or have had a subtotal hysterectomy. NB3: Individuals with premature ovarian insufficiency may prefer continuous combined MHT to cyclical combined MHT to avoid withdrawal bleeding. NB4: Continuous combined MHT is preferred in individuals with hormonally sensitive migraine because it avoids fluctuations in hormone concentrations. NB5: Do not use conjugated estrogens+bazedoxifene or tibolone in perimenopausal individuals because breakthrough bleeding can occur.

For more information on baseline assessment and considerations (including investigations) before starting systemic MHT, see A Practitioner’s Toolkit for the Management of Menopause.