MHT stands for menopausal hormone therapy, a treatment that replaces the hormones your body stops producing during menopause. It’s the most effective option available for relieving hot flashes, night sweats, and other symptoms tied to the drop in estrogen that happens as menopause begins. You may also see it referred to as HRT (hormone replacement therapy), the older and still widely used term for the same treatment.
What MHT Actually Contains
MHT centers on estrogen, the hormone responsible for most menopausal symptoms when it declines. The specific type of estrogen varies, but the goal is always the same: supplement what the ovaries have stopped making.
Which formulation you’d use depends on whether you still have a uterus. If you do, estrogen alone would cause the uterine lining to grow unchecked, raising the risk of uterine cancer. So a second hormone, a progestogen, is added to protect the lining. This combination is called estrogen-progestogen therapy (EPT). If you’ve had a hysterectomy, you only need estrogen, and the progestogen is unnecessary. This simpler version is called estrogen therapy (ET).
How It Helps With Menopause Symptoms
Hot flashes and night sweats, known clinically as vasomotor symptoms, are the most common reason people start MHT. The treatment reduces both the frequency and intensity of these episodes by roughly 90%, often within the first month. For many women, this is the difference between sleeping through the night and waking up drenched in sweat several times.
MHT also addresses a cluster of changes in the vaginal and urinary areas that develop as estrogen drops. Vaginal dryness, painful sex, and increased urinary tract infections are all part of what’s called genitourinary syndrome of menopause. Low-dose vaginal estrogen, applied locally as a cream, ring, or tablet, is the go-to treatment for these symptoms specifically. It works as well as systemic (whole-body) estrogen for this purpose but uses a much smaller dose. Even women already on systemic MHT sometimes need local vaginal estrogen added, since up to 25% of women on systemic therapy still experience vaginal and urinary symptoms.
Protection Against Bone Loss
Beyond symptom relief, MHT has a significant effect on bone health. Estrogen plays a direct role in maintaining bone density, and when it drops during menopause, bones begin to thin. Data from the Women’s Health Initiative trials showed that MHT reduced the risk of any fracture by 28% and hip fracture by 34%. Current guidelines recommend MHT for osteoporosis treatment in women who can’t tolerate other bone-specific medications, provided they’re within the safe window for starting therapy.
How You Take It
MHT comes in several forms. The most common are oral tablets and transdermal options, which include skin patches, topical gels, and sprays. For vaginal symptoms alone, low-dose creams, rings, and inserts deliver estrogen directly where it’s needed.
The choice between oral and transdermal matters beyond convenience. Oral estrogen passes through the liver before reaching the rest of the body, which increases the production of clotting factors. Transdermal estrogen absorbs through the skin and bypasses the liver entirely. This translates to a meaningful difference in blood clot risk: one large study found a 56% lower risk of clots with transdermal compared to oral estrogen. Another found that oral estrogen nearly doubled the risk. Clinical guidelines from both the UK (NICE) and the US (AACE) now recommend transdermal estrogen for anyone at elevated clot risk, including women with a BMI over 30.
The Timing Window
When you start MHT matters as much as whether you start it. Research consistently points to a “window of opportunity”: beginning therapy within six years of menopause onset, or before age 60, is associated with cardiovascular benefits and lower overall mortality. Starting well past this window, particularly more than 10 years after menopause, shifts the risk-benefit balance unfavorably for heart health.
This timing principle shapes current guidelines. The North American Menopause Society’s 2022 position statement emphasizes that the risks of MHT differ depending on the type, dose, duration, route, timing, and whether a progestogen is included. Treatment should be individualized, with periodic reassessment of whether it’s still the right choice. For women with persistent symptoms, longer use is reasonable as long as the decision is revisited over time.
Breast Cancer Risk in Context
Breast cancer risk is the concern that keeps many women from considering MHT, and the numbers deserve context. A 2019 meta-analysis found that five years of combined estrogen-progestogen therapy starting at age 50 would result in roughly one additional breast cancer case for every 50 women using it over the following 20 years. For estrogen-only therapy, that figure drops to about one extra case per 200 women.
A Cochrane review of over 43,000 women put it another way: continuous combined MHT after about five and a half years of use raised the breast cancer rate from 19 per 1,000 women to between 20 and 30 per 1,000. The risk is real but modest in absolute terms, and it’s lower with estrogen-only therapy, shorter durations, and certain progestogen types. The increase also appears to diminish after stopping treatment.
Common Side Effects
The most common side effects when starting MHT are breast tenderness and bloating, which can come from both the estrogen and progestogen components. These typically fade within a few weeks. The NHS recommends sticking with treatment for at least three months before judging whether the side effects are tolerable, since most resolve on their own in that time frame.
Who Shouldn’t Use MHT
MHT is not appropriate for everyone. Women with a history of breast cancer, blood clots, stroke, or unexplained vaginal bleeding are generally advised against systemic MHT. The same applies to those with active liver disease or a history of heart attack. Low-dose vaginal estrogen is sometimes still an option in some of these situations because very little of it reaches the bloodstream, but that decision requires careful evaluation of individual risk.