Most women think of bone loss as a problem for after menopause. Something to deal with once periods have stopped and the DEXA scan says so. The research tells a different story: the steepest bone loss of your life begins before your final period, during perimenopause, at a time when many women have no idea it is happening.
That timing matters, because the years when bone loss is fastest are also the years when doing something about it counts the most.
The short version
- Bone loss accelerates sharply in the year or two before your final period, not after it.
- You cannot feel it happening. Bone loss has no symptoms until something breaks.
- The earlier in the transition you start loading your bones, the more density you keep for the decades ahead.
Free download: the Bone Density Action Guide. What to ask your GP, how to read your T-score, and five safe starter exercises, written by Maddie.
What perimenopause actually is
Perimenopause is the transition phase leading up to your final menstrual period. It typically begins in your forties, sometimes earlier, and lasts anywhere from a few years to a decade. Menopause itself is a single point in time, twelve months after your last period. Everything before that point is perimenopause, and everything after it is post menopause.
Hormonally, perimenopause is not a gentle dimming of the lights. Oestrogen does not decline smoothly. It fluctuates, sometimes spiking higher than before, then falling further, with the overall trend heading down. Cycles become irregular, symptoms come and go, and because periods have not stopped, many women do not connect what they are feeling to the menopause transition at all.
Why bone loss starts before your final period
Your bones are constantly being broken down and rebuilt, a cycle called remodelling, and oestrogen is what keeps that cycle in balance. We covered the full mechanism in what happens inside your bones during menopause: oestrogen restrains the cells that break bone down, so when it falls, breakdown starts outpacing rebuilding.
Here is the part that surprises most women. That imbalance does not wait for your final period. In late perimenopause, as oestrogen levels begin their steeper decline, bone loss accelerates too. Research following women through the transition shows the fastest losses cluster in the window from about a year before the final period to about two years after it. Across the whole transition, women can lose in the order of ten percent of their spine bone density, and roughly half of that happens before periods have fully stopped.
Hormones fluctuate, cycles become irregular. Bone density is largely maintained, and this is the ideal time to build the habit of loading it.
Oestrogen falls steeply and bone loss runs at its fastest. What you do here has an outsized effect on the decades ahead.
The rate of loss eases but continues. Bone can still respond to loading, it is never too late to start.
"The years when bone loss is fastest are also the years when doing something about it counts the most."
Why the window matters
Think of bone density like a retirement account. The balance you carry into post menopause is what you draw down on for the rest of your life, and deposits made early compound.
A woman who starts structured strength training in perimenopause is doing two things at once. She is stimulating her bones to hold density right through the years they would otherwise lose it fastest, and she is building the muscle, balance and movement confidence that protect against falls later. A woman who waits until a post menopause DEXA scan delivers bad news can still make real progress, we see it in the clinic constantly, but she is rebuilding from a lower floor.
This is not a reason for alarm if you are past that window. Bone responds to loading at every age, and the evidence for strength training after menopause is strong. It is a reason to start now, wherever now happens to fall.
In your forties and wondering where you stand?
The Bone Density Action Guide covers what to ask your GP, how to read your T-score, and five safe starter exercises, written by Maddie.
What to do during perimenopause
You do not need to overhaul your life. You need a handful of deliberate moves, made consistently.
- Start loading your bones now. Resistance and impact based exercise, two to three times a week, at an intensity that genuinely challenges you. Bone adapts to demand, and light exercise that never pushes does not send the signal. The type of loading matters as much as simply staying active.
- Have the bone conversation with your GP. If you have risk factors, a family history of osteoporosis, early menopause, previous fractures from minor falls, long term steroid use or low body weight, ask whether a baseline DEXA scan makes sense now rather than at 70. A baseline gives every future scan something to be compared against.
- Look after the raw materials. Adequate protein, calcium and vitamin D. Bone cannot rebuild without supply, though supply alone, without loading, does not build bone either.
- Track your cycle. Irregular cycles are data. They help you and your GP place where you are in the transition, which in turn tells you how close the critical window is.
The takeaway
Perimenopause is not the warm up to the main event. For your bones, it is the main event. The steepest losses of the transition begin before your final period, they happen silently, and the single most protective thing you can do, structured loading through strength training, works best when it starts early.
If you are in your forties and your cycles are changing, this window is open for you right now. That is not a deadline to panic about. It is an opportunity most women are never told they have.
Find out where your bones stand
Our women's health Exercise Physiologists build bone loading programs around your stage of the transition, your history and your DEXA results if you have them. Start with a free 10 minute call, no assessment, no commitment, or book a Women's Health Initial directly.
Private health rebates apply, so check your extras cover. With a GP Chronic Disease Management plan, Medicare rebates may cover part of your visits.