MHT, the fear and the facts.
Reviewed Dr Jo Mackson, MBBS FRACGP
Published July 2026
Reading time About 6 minutes
The headline that frightened a generation.
In 2002, a single study changed how a generation of women were cared for. It reported that hormone therapy raised the risk of breast cancer and heart disease, the news travelled the world, and within a year prescriptions collapsed. Women already taking MHT stopped, often overnight. Women who came after were rarely offered it, and when they were, it arrived so wrapped in warning that many said no.
The fear was real. So was the cost of going without: years of hot flushes, broken sleep, thinning bones, and vaginal and urinary symptoms that a safe treatment could have eased. What almost no one heard was that the women in that study were, on average, 63 years old, more than a decade past menopause. The picture for a woman starting MHT around the time her periods stop is very different, and twenty years on, with the study read properly and better ones run since, it looks far more reassuring than the headlines of 2002.
What MHT does, and what it is for.
Most women take MHT because they feel awful and want to feel better. Menopause is not just hot flushes. As both oestrogen and progesterone fall, women can get night sweats, broken sleep, low mood and anxiety, brain fog, joint aches, and more. MHT, which replaces those hormones, can help with many of these. The evidence is strongest for hot flushes, night sweats, and the sleep they wreck. For things like mood and brain fog, it helps some women a lot and others less. But the bottom line is simple: if you are having symptoms of perimenopause or menopause that are affecting your quality of life, MHT is worth considering.
Some of the most common menopause symptoms are vaginal dryness, discomfort during sex, and urinary changes like needing to go more often or recurrent infections. These come from falling oestrogen in the vaginal and bladder tissues, and they respond very well to a small amount of oestrogen applied locally, as a pessary or cream. When oestrogen is used locally, very little reaches the rest of the body, which means the risks of MHT discussed in the rest of this guide do not apply in the same way. It can be used by itself or added alongside MHT, it is safe to use for as long as the symptoms need it, and it is an option for almost all women, including those who cannot take MHT that works through the whole body, and, after discussion with their doctor, many women who have had breast cancer.
MHT also protects your bones. After menopause, the drop in oestrogen speeds up bone loss and fractures can become more common. Replacing oestrogen slows that loss and reduces the risk of breaking a bone. For women around the time of menopause, MHT is a first-line option for preventing and treating osteopenia and osteoporosis, and is encouraged wherever there is no reason to avoid it.
Beyond symptoms and bones, there is emerging evidence that shows promising benefits for heart health, metabolism, and the brain. While this evidence is exciting, we do not yet have the data to recommend MHT for these benefits alone. What the emerging evidence does and does not show matters too much to brush over in a mini guide, so we have written a Deep Dive that sets out what each benefit actually is, how strong the evidence is, and how to think about whether it might apply to you.
The risks, smaller than you were told.
Breast cancer is the risk women fear most with MHT, and the fear has a specific source. In 2002, a very large American study called the Women’s Health Initiative was stopped early after reporting that MHT increased breast cancer risk, with a headline figure of a 26% rise. Understandably, that caused widespread panic. Within a year, women came off MHT in huge numbers, doctors stopped prescribing it, and breast cancers that would have appeared anyway were blamed on the hormones, which only seemed to confirm the fear. But there were two big problems with how that result was read, and if they had been given the same airtime as the original headline, two generations of women might not have missed out on the benefits of MHT.
The first problem: the 26% was a relative increase, not an absolute one. In real numbers, the study saw roughly 4 extra cases of breast cancer per 1,000 women taking MHT over 5 years, compared with women who were not. The second: the findings did not apply to all MHT, or all women. The study looked only at oral conjugated equine oestrogen with a synthetic progestogen, in women whose median age was 63, most of them well over a decade past menopause.
Two decades on, with the study seen for what it does and does not show, and better ones run since, the picture is far less frightening. Combined MHT, which is oestrogen plus a progestogen, does carry that small increase in risk. But oestrogen on its own does not raise the risk at all, and may even lower it slightly. And when micronised progesterone is used instead of a synthetic progestogen, there is no measurable extra risk for at least the first five years.
Another crucial bit of information, often missed when considering the link between MHT and breast cancer, is that MHT does not appear to create a breast cancer that was never going to occur. If a woman was never going to develop breast cancer, MHT is not expected to cause it. What it can do is bring one forward: if very early, slow-growing cancer cells are already present, the hormones can give them an environment to grow a little faster, so a cancer that was already on its way is found sooner than it otherwise would have been. That is a different, and less frightening, idea than MHT causing breast cancer.
The other risk worth understanding is blood clots. When the oestrogen part of MHT is taken orally as a tablet, it passes through the liver first, where it can increase the production of several clotting factors, making the blood a little more prone to clotting. When oestrogen is instead absorbed through the skin as a patch or gel, it skips that step and does not raise the clot risk in the same way.
The added clot risk is small, but because a clot can travel to the lungs, or cause a stroke if it reaches the brain, it is worth taking seriously. A woman’s own background risk adds an important layer to the numbers below, and the Deep Dive works through that in detail.
Almost everything in this guide depends on you specifically. The first level is your own baseline: your personal risk of a broken bone, of breast cancer, of a clot, and of heart disease is set by your age, family history, weight, whether you smoke, how much you drink, and your medical history, well before MHT is added. The second level is the MHT itself, because the type and the route change the risks. The third level is your own weighing of it, how much your symptoms are affecting your life against how much risk you are comfortable with. For clots specifically, a higher body weight, smoking, high blood pressure, migraine with aura, or an inherited clotting condition all raise the baseline, which is part of why MHT through the skin is preferred. This is why hormonal treatment is never one-size-fits-all. The right decision is a personalised one, weighing your own risks and benefits, made with your doctor.
Who, what, where, and when.
Four questions shape every MHT decision. Who it is for, meaning which woman and her own risks. What type of MHT. Where it goes in, through the skin or by tablet. And when, the one most people have never heard of, and the one this section is about: the window of opportunity.
When you start MHT matters as much as whether you start. Begun around the time of menopause, usually before 60 or within 10 years of your last period, the benefits are at their largest and the risks at their smallest. Begun much later, in your late sixties or beyond, the benefits fade and some risks rise.
MHT is not a decision you make once and never look at again. It is started, then reviewed and adjusted as your symptoms, your health, and the evidence itself change over time. For most women under 60 with bothersome symptoms and no strong reason to avoid it, the balance favours treating, usually with oestrogen through the skin and micronised progesterone. But the right answer is the one you reach with your doctor, looking at your symptoms, your own risks, and your age together. The answer is rarely a simple yes or no, because risk, medicine, and women are never quite that black and white. It is a decision worth taking the time to get right, with someone who can weigh it all up with you, and one you are always allowed to revisit as your life, and the evidence, change.
So there you have it. Our Mini Guide on MHT. If we’ve left you feeling at all curious about the deeper science, or wanting a proper walk through the benefits and the risks, our Deep Dive is where to go next.
This Mini Guide is the taste test of MHT. The Deep Dive is the full degustation. It covers every tasty morsel: why the 2002 study frightened everyone and what it actually found, what the emerging evidence really says about the heart and the brain, and the one clot-risk figure worth taking to your appointment.
It is long. It is detailed. It is the education on this topic we think every woman should have had years ago. We are not going to insist you read it. Life is busy, and ‘long-form medical education’ is not on every woman’s reading list. But if you ever find yourself wondering, the Deep Dive is here when you are. Read it here.