Your Cycle Is Changing. Your Hormones Are in Flux. Here’s the Full Story.
Reviewed Dr Jo Mackson, MBBS FRACGP
Published June 2026
Reading time About 35 minutes, or 5 to 7 per part
Short on time? Start with the Mini Guide, then come back here when you want the full picture.
This guide follows on from the first in our series, the Late Reproductive Stage guide. If you have already read it, some of what follows will sound familiar, but we’d gently encourage you not to skip ahead. This guide covers the oestrogen part of the story, which the first guide only touched on. And that part is where things start to get “interesting”.
Before we begin our deep dive into perimenopause, we need to acknowledge why you are reading this in the first place.
Women’s health, and women’s hormonal health in particular, has been under-researched, over-simplified and too often dismissed, leaving most of us trying to make sense of our own bodies without the education we need to do so. That is why this Deep Dive exists. Because as women, most of us have never been taught the specific biology that shapes so much of our lives. School sex ed for most of us was a brief tour of the fallopian tubes, an introduction to pads and tampons, and the unforgettable awkwardness of a condom on a banana. Our mothers, aunties, and grandmothers were often taught even less, resulting in a knowledge gap that has been quietly handed down for generations. This stops here.
So bear with us if this Deep Dive gets a bit science-heavy, and we apologise in advance for any flashbacks to the Year 8 science lab. We promise it will be worth it, because we believe knowing how the cycle that underpins your life as a woman works is far more useful than knowing how plants turn sunlight into food. Unless you are a botanist.
Because once you understand the why, everything that follows, the symptoms, the investigations, the treatment options, starts to make sense.
So yes, there will be medical terminology, the odd graph, and drug names that look like a toddler was let loose on a keyboard. Read it at your own pace. Skip ahead if you need to. Come back to the parts that matter most for you. Consider this the education that is long overdue. And don’t worry, there is no pop quiz at the end. Although if "luteal phase" comes up at your next trivia night, you can thank us later.
Now, before we let you loose below, a quick note about that medical terminology. If you are reading online, just toggle your mouse over the word and you can get a brief definition. If you have printed and are reading it old school, hats off. We have included a glossary at the end of the guide just for you.
Perimenopause: The Biology Behind Life’s Least Favourite Plot Twist.
You Were Born With All the Eggs You’ll Ever Have.
This story begins, well, at the beginning.
Before we are even born, our ovaries are set up for a life of reproduction. We are born with our lifetime supply of eggs, somewhere between one and two million. By puberty, that number has naturally declined to around 300,000 to 400,000. By the mid-thirties, approximately 25,000 to 50,000 are left. And of all those hundreds of thousands, only about 400 to 500 will ever actually ovulate.
So what happens to the rest? They are lost to atresia, a continuous process of programmed cell death that happens quietly in the background, regardless of whether you are on the pill, pregnant, or cycling regularly. Atresia is not a malfunction. It is the biology that underpins every hormonal shift you are about to read about.
A Quick Tour of Your Cycle.
Because this shift can only make sense if you know the normal rhythm first.
To understand what changes during perimenopause, you need to understand what your hormones do during a typical cycle first.
The menstrual cycle is the rhythm your hormonal system has run on since puberty: a tightly coordinated conversation between your brain and your ovaries that repeats itself month after month.
Let me introduce you to the menstrual cycle. Your monthly reminder that we are the ones carrying the human race forward, whether we asked to or not.
The cycle has two halves: a build-up to ovulation called the follicular phase, and a waiting period after ovulation called the luteal phase, when the body holds steady to see whether a pregnancy is beginning.
A less textbook version? Think of the menstrual cycle as preparing a guest room for a notoriously flaky friend. The first half is all preparation. Oestrogen rises, the lining thickens, an egg readies itself for ovulation. You put fresh linen on the bed, plump the pillows, place fresh flowers on the nightstand. The second half is the wait. If she turns up, the room is all ready for her stay (biologically speaking, you’re pregnant). More often than not, she sends a late text and is a no-show. You strip the bed, toss the wilted flowers, and the cycle begins all over again.
Day one of the cycle is the first day of your period. In hormonal terms, this is the body saying: not pregnant this month, time to start again.
Your brain sends a hormonal signal called FSH, or follicle-stimulating hormone, to your ovaries. Its job is to encourage a group of follicles to start growing. Follicles are small fluid-filled sacs in the ovaries, and each one contains an immature egg.
These follicles now enter a kind of quiet competition. One follicle grows faster than the others and becomes the dominant follicle which is most likely to release an egg that cycle.
As this dominant follicle grows, it produces oestrogen. Oestrogen builds up the lining of the uterus, getting it ready in case a pregnancy needs to settle in.
Around the middle of the cycle, once oestrogen has risen high enough, the brain sends another signal. This one is called LH, or luteinising hormone.
LH is a trigger message telling the dominant follicle it’s show time, time to rupture and release its egg.
And ta da. Ovulation.
After ovulation, the empty follicle does not just disappear. It transforms into a structure called the corpus luteum, kind of like the follicle’s second act.
The corpus luteum sits in the ovary for the next 12 to 14 days and produces progesterone. Progesterone’s job is to hold the uterine lining steady and support an early pregnancy if that was on the menu that month.
If pregnancy does not occur, the corpus luteum breaks down. Progesterone levels fall. The uterine lining becomes unstable and eventually sheds.
Enter: your period.
And the cycle begins again.
Cycles vary, and that variation is often completely normal. A typical cycle can run anywhere from 21 to 35 days, ovulation does not always happen on day 14, and the length of the follicular half, the lead-up to ovulation, is the part that fluctuates most. The luteal half, the two weeks after ovulation, is the more consistent half, and tends to stay around 12 to 14 days. So when cycles change, it is most often the follicular half doing the shifting.
Some variation across the month, across the year, or across life stages is expected. But cycles that are consistently shorter than 21 days, longer than 35 days, irregular without a clear pattern, very heavy, very painful, or accompanied by bleeding between periods are worth raising with your doctor. Not because something is necessarily wrong, but because the cycle is one of the most useful signals we have about how your hormonal system is working, and a shift is always worth understanding.
Now we have the two key puzzle pieces in place. First, you were born with all the eggs you will ever have, and that number has been slowly declining ever since. Second, your menstrual cycle is a carefully coordinated conversation between the brain and the ovaries, designed to recruit a follicle, ovulate an egg, and prepare and support a uterus to hold a pregnancy. Put those two ideas together, and now perimenopause will hopefully make much more sense.
It All Starts with Progesterone.
As we get older, our eggs get older with us. Our egg reserve declines not only in number, but also in quality. And as this happens, the hormonal changes of perimenopause can begin to appear.
Towards the end of our reproductive years, the follicle that wins the race to ovulation may be less vigorous than it once was. The corpus luteum it leaves behind is only as good as the follicle it came from, and so it can be less robust too.
A less robust corpus luteum can produce less progesterone. That might mean a slower rise at the beginning, a lower peak in the middle, or a steeper drop at the end.
And the knock-on effect of that can be felt everywhere: in your periods, your sleep, your mood, your migraines, and your ability to tolerate loud chewing in the week before your period.
Your hormones are not behaving badly. They are just the messengers. It is the follicles that are not quite what they used to be.
This is often the first hormonal shift women notice, and it can begin years before any obvious change in cycle length.
That change in cycle length, when it arrives, comes from ovulation itself becoming less reliable. Up to this point ovulation has happened on a fairly predictable schedule, even when the corpus luteum that follows is weaker than it once was. That predictability is the next thing to go. For many women the first sign is cycles getting shorter, with ovulation arriving earlier than it used to and periods coming closer together. Later the pattern reverses: ovulation is delayed, and some months the dominant follicle does not release its egg at all. A cycle where ovulation does not happen is called an anovulatory cycle, and these become more common as perimenopause progresses, when cycles tend to lengthen and turn unpredictable.
Whether your periods arrive sooner, later, or skip altogether, the timing of the cycle is moving because the timing of ovulation is moving. This is generally where the formal line is drawn: a persistent, measurable change in your cycle length, in either direction, is what marks the move from the late reproductive stage into early perimenopause, and we come to exactly what that means a little further on. The reduced progesterone many women notice first, and the cycle changes they can measure later, are two parts of one shift, ovulation becoming less reliable as the reserve runs low.
That strict, cycle-based definition is an area of active change in medicine right now, as the field reckons with how many women feel the shift long before their cycles show it. So we treat the criteria as a useful guide, not a gate. We listen to what you tell us about your own body, rather than waiting for the calendar to give us permission to take it seriously.
Now It’s Oestrogen’s Turn.
Following the decline in progesterone, oestrogen is not far behind. But when oestrogen begins to shift, it does not do so gradually. It does so with the erratic chaos that defines perimenopause and sets it apart from the postmenopausal life that follows.
To understand why the hormonal transition of perimenopause is so chaotic before things eventually settle, we are faced with a slightly uncomfortable truth: female biology exists, first and foremost, for the purpose of reproduction. We are, of course, so much more than what our biology dictates, and for many women, carrying a pregnancy is never part of their story, by choice or by circumstance. But biology is biology. Our reproductive system is hormonally wired to ensure ovulation happens. Every month. Without fail. And it keeps pushing to make that happen, even as your ovaries become less and less cooperative.
As your egg reserve depletes further, the follicles that remain respond less reliably to the FSH message from the brain. The brain senses this poor response and, due to our biological imperative, reacts by producing more and more FSH, pushing harder and harder to get the ovaries to respond. The result is hormonal chaos. Some cycles, the ovaries over-react and produce a spike of oestrogen. Other cycles, they barely respond, and oestrogen levels never rise. This is not a smooth or predictable decline. Instead, oestrogen levels fluctuate wildly, and can look completely different from one cycle to the next.
What this means is that you are not dealing with one hormonal shift. You are dealing with four: low progesterone, spikes of high oestrogen, stretches of low oestrogen, and the symptoms driven by the rapid swings between them. It is the unpredictability of the whole picture that the body struggles to adapt to.
This is also why some perimenopause symptoms feel different from anything you have experienced before. The brain fog that comes and goes, the mood swings that don't track your cycle, the sleep that is unpredictable, the early hot flushes you didn't expect this side of menopause, these are driven by the volatility itself, not by any single hormone level being too high or too low.
Understanding this is what helps us make sense of what can feel like a wide-ranging, unpredictable set of symptoms. And it gives us a clear way to think about what to do about them.
Perimenopause is not a single hormonal state. It is a years-long transition where no two cycles look the same. And that unpredictability is precisely what makes it so hard to live through.
So, How Do I Know If I’m in Perimenopause?
With that picture of what is happening hormonally, the obvious next question is whether you are in it.
Perimenopause lasts, on average, 4 to 10 years, beginning most commonly in the mid-to-late forties. The average age of menopause in Australia is 51, with a normal range of 45 to 55. That said, some women start experiencing symptoms of this transition considerably earlier, even in their mid-thirties.
Clinically, perimenopause is diagnosed when you have a noticeable and persistent change in cycle length of 7 or more days between consecutive cycles, alongside symptoms consistent with hormonal fluctuation. Later in perimenopause, longer gaps of 60 days or more become increasingly common as ovulation becomes less frequent.
Here is the part that often gets missed. If you don't yet meet these criteria, that doesn't mean nothing hormonal is happening. Many women experience symptoms, sometimes significant ones, driven by progesterone deficiency and early oestrogen volatility, before their cycle changes in any measurable way. The diagnostic criteria exist because medicine needs boxes, but a gradual, highly variable biological transition does not always fit neatly into one of them. If that sounds like you, our Late Reproductive Stage guide covers exactly this in detail.
There is no blood test that diagnoses perimenopause, and this is not a gap in the evidence. It is the evidence. Hormone levels in this stage are too variable, too individual, and too dependent on timing to be useful as a diagnostic test. FSH can be normal one week and elevated the next. Oestrogen can spike and crash within the same cycle. AMH tells us about ovarian reserve, but not about the quality of those eggs, nor how a woman is experiencing that reserve declining. And because every woman’s hormonal baseline is uniquely her own, there is no single number that definitively diagnoses high or low progesterone, or confirms that perimenopause has arrived.
Blood tests can however support the clinical picture in certain circumstances, particularly in younger women with cycle change, those without periods, or when the diagnosis is uncertain. But they cannot make or exclude a diagnosis. The diagnosis is clinical: it is made from history, symptoms, age, and the careful exclusion of other causes.
WHAT ABOUT AT-HOME TESTING?
DUTCH testing, salivary hormone panels, and the range of direct-to-consumer hormone tests available online are not validated tools for diagnosing perimenopause. Measuring what your body has already broken down and excreted in your urine does not tell us what your hormones are doing at a tissue level. Which is why there is no clinical evidence to support using these results in diagnosis or treatment.
We understand the appeal. When you are not getting answers through conventional routes, a detailed hormone report with graphs that match your symptoms finally feels like someone is listening. But these tests are expensive, largely unregulated, and marketed with a confidence the evidence simply does not support. These tests are part of an industry that has learned to profit from the dismissal women have lived through, from the appointments that ended without answers, and from the search for somewhere to be taken seriously. You should not have to choose between being dismissed and being sold to. Education is a third option.
Making the Symptoms Make Sense.
No Two Experiences Are the Same.
Why perimenopause shows up so differently from one woman to the next.
No two women experience perimenopause the same way. The hormonal changes themselves are different for every woman, shaped by genetics, lifestyle, metabolic health, stress, and the specific pattern of your ovarian decline. The experience of those changes is just as individual. Some women sail through with minimal disruption. Others find it profoundly destabilising. Both experiences are valid.
There are more than 30 recognised symptoms of perimenopause, and likely many more we have not yet linked back to it. Here are some of the most common ones, and why they happen.
The Usual Suspects.
Symptoms most women notice.
| Symptom | What is happening |
|---|---|
| Hot flushes and night sweats | Oestrogen fluctuations disrupt the brain’s internal thermostat, causing it to misread normal body temperature as overheating. The body responds by rapidly trying to cool itself down, hence the sudden flush of heat, redness, and sweating. At night, the same process can cause drenching sweats, even on the coolest nights. |
| Sleep disruption | Several things can affect sleep during perimenopause. Progesterone loss reduces the brain’s natural calming activity, oestrogen fluctuation disrupts serotonin and REM sleep regulation, and night sweats can cause physical waking. Women may struggle to fall asleep, stay asleep, or both, with or without hot flushes contributing. |
| Anxiety and mood changes | A metabolite of progesterone called allopregnanolone acts on GABA-A receptors in the brain, the brain’s main calming system. When progesterone falls, the natural calming buffer it provides fades with it, leaving many women feeling unusually anxious, more reactive, and more on edge than they are used to. Oestrogen fluctuation adds to this, destabilising the mood-regulating neurotransmitters serotonin, dopamine, and noradrenaline. The result can be heightened reactivity, irritability, low mood, or a general sense of emotional fragility that feels unfamiliar. Many women describe a not-myself feeling. Anxiety, anger, or sadness that comes without warning and often well out of proportion to any trigger. |
| Irregular or changed periods | As ovulation becomes less reliable, cycles can shorten, lengthen, become heavier, lighter, or simply unpredictable. With less progesterone holding the uterine lining steady, the lining itself becomes less stable. This can show up as heavier or prolonged bleeding, spotting before or after the main bleed, or cycles that arrive with no warning. |
| Brain fog and memory | Oestrogen supports brain function in several important ways, including cerebral blood flow, memory consolidation, white matter integrity, and the regulation of mood and cognition through neurotransmitter pathways. The instability of oestrogen impairs these processes and can show up as word-finding difficulty, poor short-term memory, and difficulty concentrating. Reassuringly, the evidence suggests these are largely temporary functional changes driven by the fluctuations themselves, not permanent structural ones. Symptoms typically improve once hormonal stability is restored. |
| Genitourinary symptoms | The vulval, vaginal, and lower urinary tract tissues are richly oestrogen-dependent. As oestrogen declines, these tissues begin to thin, lose elasticity, produce less natural lubrication, and shift in their pH, which also affects the local microbiome. This can show up as vaginal dryness, discomfort, pain with intercourse, urinary urgency, incontinence, and increased susceptibility to urinary tract infections and vaginal infections. Unlike vasomotor symptoms, these tend to worsen over time without treatment. Which is why recognising changes, and treating them, matters. |
| Low libido | Low libido in this stage is driven by a combination of factors: oestrogen decline, sometimes testosterone decline (a gradual, age-related shift rather than a perimenopause-specific one), and the indirect effects of poor sleep, mood changes, and genitourinary discomfort. It is one of the most undertreated symptoms of perimenopause, in large part because neither women nor their doctors tend to bring it up. |
The Unusual Suspects.
The ones that catch you off guard.
Sometime perimenopause can show up in ways that seem so far detached from our reproductive biology, that they often are explained away. Either put down to stress, ageing, or just life, before anyone makes the hormonal connection. The list below is not exhaustive. If something has shifted for you and you can't explain it, it is worth considering whether perimenopause is part of the picture.
| Symptom | What is happening |
|---|---|
| Joint pain and stiffness | Both oestrogen and progesterone have anti-inflammatory roles and support collagen and connective tissue health. Their fluctuation and decline can trigger joint pain, morning stiffness, and tendon sensitivity, often in the hands, knees, and hips, that is frequently mistaken for early arthritis or overuse. Frozen shoulder and lateral epicondylitis (tennis elbow, and yes, you do not need to have been near a court) are also reported with increased frequency in this life stage. |
| Palpitations | Autonomic nervous system changes driven by oestrogen fluctuation can cause an increased awareness of the heartbeat and sometimes slightly irregular rhythms. They are usually benign in women without cardiac history, but always worth checking out, to make sure nothing else is going on before attributing them to hormones. |
| Headaches and migraines | Oestrogen fluctuation is a well-established migraine trigger. Women with a history of hormonal migraines often find they worsen in perimenopause, particularly around ovulation and before menstruation when oestrogen drops sharply. |
| Skin and hair changes | Oestrogen supports collagen production and sebaceous gland activity. Its fluctuation can cause dryness, loss of elasticity, increased sensitivity, and in some cases, hormonal breakouts. Hair changes are also common, with thinning at the temples and crown, and unwelcome new growth in other places (I’m looking at you, pesky chin hair). All driven by the shifting balance between oestrogen and testosterone. |
| Nerve and sensation changes | Oestrogen also affects how nerves signal and how the brain processes sensation. This can show up in a few ways that often surprise women because they do not seem hormonal at first glance. Formication is the medical term for the itching, crawling, or tingling sensation on the skin with no visible cause. Brain zaps, those brief electric-shock-like sensations in the head, are also reported, as is burning mouth syndrome, a persistent burning or scalded feeling in the mouth or tongue with no obvious explanation. Less common, but worth naming, because women who experience these symptoms often spend a long time trying to make sense of them before the hormonal connection is made. |
| Tinnitus | Some women report new or worsening tinnitus (ringing in the ears) in perimenopause, thought to involve oestrogen’s role in inner ear fluid balance and auditory nerve function. |
Changes in bleeding pattern are an expected part of perimenopause, but not all irregular bleeding is hormonal. Heavy bleeding, bleeding between periods, and bleeding after intercourse warrant investigation to exclude structural causes (fibroids, polyps, adenomyosis), cervical changes, sexually transmitted disease, and, in rare but important cases, uterine lining abnormalities. So while changes are often normal, they are always worth discussing with your doctor.
Ruling Things Out First.
Are We Sure It’s Just Perimenopause?
Perimenopause is a clinical diagnosis, made from history, symptom pattern, and age, without needing investigations or blood tests. But before attributing symptoms to hormonal change, it is important to exclude conditions that can look, feel, and present almost identically to perimenopause. Or that may coexist with perimenopause, amplifying its symptoms.
| Rule out | Why it matters |
|---|---|
| Thyroid dysfunction | Symptoms of both hypothyroidism and hyperthyroidism can overlap with perimenopausal symptoms. Autoimmune thyroid disease (Hashimoto’s) is also significantly more common in women and can emerge or worsen in this life stage. A simple TSH is an easy way to screen for this. |
| Iron deficiency | Heavier or more irregular bleeding significantly increases the risk of iron deficiency in perimenopause, alongside other common contributors like low dietary intake and poor absorption, and many women are iron depleted or deficient without being aware of it. Iron deficiency can compound fatigue, cognitive symptoms, mood disturbance, and sleep disruption. You can be iron deficient without being anaemic, which means a normal haemoglobin does not rule it out. Ferritin is the test that reflects your iron stores, and the laboratory cutoff (often around 30) does not reflect what is clinically optimal. We generally aim for a ferritin above 50 at least, with 75 or higher preferred in symptomatic women. |
| Vitamin B12 and folate deficiency | B12 deficiency presents with fatigue, cognitive symptoms, mood disturbance, and tingling or numbness in the hands and feet, and is more common than is often appreciated. The usual list of risk factors includes dietary restrictions (vegetarian and vegan diets in particular), long-term use of metformin, GLP-1 medications, the pill, and acid-suppressing medications, alongside autoimmune conditions like pernicious anaemia and coeliac disease. Age also plays a role, as the stomach produces less acid over time, which reduces how well B12 is absorbed. |
| Vitamin D deficiency | Vitamin D deficiency is common in Australia, particularly in winter, in women, and in those who spend most of their time indoors. It contributes to fatigue, low mood, and musculoskeletal symptoms, and matters more in this stage as bone turnover accelerates with declining oestrogen. The laboratory cutoff (50 nmol/L) does not reflect what is clinically optimal, so we generally aim for a level of 75 at least. |
| Primary mood disorder | Anxiety and depression in this stage may be primary conditions, driven by hormonal change, or both at once. A new onset anxiety disorder with no prior history should always prompt thinking about the hormonal picture. And pre-existing mental health conditions often worsen significantly in perimenopause. Treating the hormonal component, where present, can substantially improve the psychiatric one. |
Now, How Can We Help?
So, you have a frozen shoulder, you are hot flushing, and you have not slept a full night all month. Where do we go from here? Once perimenopause is recognised and other contributors ruled out, the conversation about how to manage it can begin. That conversation has two parts: the foundations, and the treatments that sit on top of them.
The Foundations Come First.
The foundations come first. Nutrition, movement, sleep, stress management, and connection are not optional extras in perimenopause. They are the platform on which everything else sits, and they have real, well-evidenced effects on hormonal health, symptom severity, and long-term wellbeing. We cover these in detail in a separate guide.
We know how this lands. "Eat better, sleep more, exercise, manage your stress" is advice every woman has been given a hundred times, often as a substitute for being properly listened to. We get the eye-roll. And yes, we know that doing it is harder than saying it. But the evidence really is on the side of the foundations. In many cases they are as effective as, or more effective than, anything we can prescribe. If we could bottle a Mediterranean diet, eight hours of sleep, two resistance sessions, and 50K steps a week, we would. Until then, we are stuck with doing the work. But it is worth doing, and we will help you get started.
Lifestyle change takes more effort, more time, and more patience than a prescription. In many cases, it is far more powerful.
Once the foundations are in place, or at least underway, the conversation about hormonal and non-hormonal support can begin. Perimenopause management has three jobs to do at once: symptom control, contraception, and bleeding control. Ovulation is still happening, even if unpredictably, and pregnancy remains possible until 12 months after the final period (if you are over 50) or 24 months (if under 50). Here are some of the options we use to help manage this stage
The Hormonal Toolkit.
| Option | What it is, and who it suits |
|---|---|
| MHT: Oestradiol +/- ProgestogenGels: Estrogel, Sandrena. Patches: Estradot, Estraderm MX, Estramon. Combined patch (sequential): Estalis Sequi. Oral oestradiol: Estrofem, Progynova, Zumenon. Combined oral: Femoston, Bijuva. Body-identical progesterone: Prometrium. Synthetic progestogens: Provera, Primolut N. | MHT is the current evidence-based standard for managing perimenopausal symptoms. It typically combines oestradiol (the body’s main oestrogen) with a progestogen, given to protect the uterine lining for women who have a uterus and to help with symptoms. There are various doses and several different ways to deliver each hormone, with the choice depending on preference, safety, and tolerability.Who it suitsHot flushes and night sweats, mood changes, joint pain, libido, and the early genitourinary symptoms. Micronised progesterone can also sometimes help with sleep and mood through its calming effect on the GABA-A system. WORTH KNOWING: The oestradiol in the patch and gel are absorbed through the skin, which means they bypass the liver and carry a much lower clotting risk than oral oestrogen. Micronised progesterone is generally better tolerated than the older synthetic progestogens and has a more reassuring breast cancer risk profile. One important caveat: MHT is not a contraceptive, and it does not control bleeding. Whatever your cycle has been doing, it will keep doing. |
| MHT + Mirena IUD | We can also use oral or transdermal oestradiol as above for the systemic symptoms, with a Mirena IUD providing the progestogen component locally in the uterus.Who it suitsAnyone who wants reliable contraception alongside MHT, or who is dealing with heavy or irregular bleeding alongside other symptoms. Also a useful option for women who do not tolerate oral micronised progesterone. WORTH KNOWING: The Mirena releases its progestin locally in the uterus, which protects the lining for 5 years without the systemic effects of oral progesterone. For some women, however, there is some absorption beyond the uterus, and for those women the side effects of systemic progestin (mood changes, breast tenderness, low mood) can still occur. Most women bleed very little or not at all on this combination. If inserted at age 45 or older, it can be left in for up to 10 years for contraception. If inserted earlier, the duration is up to 8 years. |
| Combined Oral Contraceptive Pill (COCP)Body-identical options: Zoely, Qlaira, Nextstellis. | A daily pill that suppresses your own hormonal cycle and replaces it with a steady, predictable dose of oestrogen and progestogen. Provides symptom control, cycle regulation, and reliable contraception.Who it suitsWomen who need contraception and whose symptoms are driven more by the unpredictability of the perimenopausal cycle than by low hormone levels. Particularly useful when erratic cycles and unpredictable bleeding are part of what is making life difficult. WORTH KNOWING: The pill is not the same as MHT. It uses higher doses of mostly synthetic hormones, designed to override your natural cycle rather than supplement it. The newer body-identical pills use oestradiol instead of the older synthetic ethinylestradiol, which gives them a more favourable cardiovascular and metabolic profile. They are gentler on the body and increasingly preferred where they suit. The pill is generally avoided in women with migraine with aura, a history of blood clots, uncontrolled blood pressure, smoking, or a BMI above 30. |
| Progesterone-Only Pill (POP) +/- MHTSlinda (drospirenone). | A daily progesterone-only pill that suppresses ovulation in most cycles, providing reliable contraception without any oestrogen. Transdermal oestradiol can be added separately for the systemic symptoms.Who it suitsWomen who cannot use oestrogen-containing contraception but still want both contraception and symptom relief. Slinda also helps with the symptoms driven by hormonal fluctuation, in the same way the COCP does, by providing a steadier hormonal background. WORTH KNOWING: A useful combination, this is an off-label approach but very much worth exploring with your doctor. |
| Local (Vaginal) Oestrogen or DHEAVagifem, Ovestin (vaginal oestrogen). Intrarosa (DHEA). | A low-dose oestrogen cream or pessary, or a DHEA pessary, used directly in the vagina to treat the tissues that need it most.Who it suitsVaginal dryness, discomfort, pain with sex, urinary urgency, and recurrent UTIs. Can be used on its own or alongside any of the systemic options above. Also a safe and effective option for many women with a history of breast cancer, where systemic MHT may not be appropriate. This should always be discussed with your oncology team, but it is increasingly supported in the breast cancer survivorship literature. WORTH KNOWING: Almost none of the hormone is absorbed into the bloodstream, which means this can be used long-term without needing progesterone cover. These symptoms do not improve on their own. They are very treatable and have huge impact on quality of life. |
MHT (menopausal hormone therapy) is now the preferred term over HRT in most current guidelines. The shift in language reflects a shift in approach: supporting a physiological transition with a focus on symptoms and long-term health, rather than simply replacing lost hormones.
You may also encounter the terms natural hormones, bio-identical hormones, and body-identical hormones, often used loosely. Body-identical refers to regulated prescription hormones (like the oestradiol patches and micronised progesterone we have discussed in this guide) that have the same molecular structure as the hormones your body makes itself. Compounded bio-identical hormones, by contrast, are custom-made preparations from compounding pharmacies. They are often marketed as more natural or more personalised, but are not held to the same standards of regulation, dose consistency, quality control, or safety evidence as approved pharmaceutical products. The AMS (Australian Menopause Society), RACGP (Royal Australian College of General Practitioners), and Sydney Women’s Wellness do not support their use.
The Non-Hormonal Toolkit.
For women who cannot or prefer not to use hormonal therapy, the non-hormonal toolkit has grown considerably in recent years. None of these options replace MHT for the breadth of effect it offers, but each has an evidence base for specific perimenopausal symptoms and a place in the right clinical picture.
| Option | What it is |
|---|---|
| Fezolinetant (Veoza) | A relatively new medication developed specifically for hot flushes and night sweats. It works directly on the part of the brain that controls temperature regulation, without touching reproductive hormones. A meaningful option for women who cannot use hormonal therapy. |
| SSRIs and SNRIs | Better known as antidepressants, but several of them, paroxetine, escitalopram, and venlafaxine in particular, have good evidence for reducing the frequency and severity of hot flushes. The bonus is that they often help with the mood and anxiety changes of perimenopause at the same time, which for many women is part of what makes the symptom load so heavy. |
| Gabapentin, Oxybutynin and Clonidine | A range of medications that can be used off label that have evidence for vasomotor symptoms and sleep disruption. They don’t work for everyone, but they are definitely worth exploring if MHT is the right choice for you. |
| Cognitive Behavioural Therapy (CBT) | Often overlooked because it is not a tablet, but the evidence here is strong. CBT does not stop hot flushes from happening, but it changes how disruptive they are, and it has good evidence for improving sleep and supporting mood through the transition. A worthwhile option in its own right, or alongside any of the above. |
The Supplement Aisle, Demystified.
The supplement market aimed at perimenopausal women is enormous, and the quality of evidence behind it varies wildly. There are a few reasons for that. Supplements are not regulated to the same standard as medications. They do not need to prove they work before they can be sold, and the advertising rules they sit under are far looser than the ones applied to anything prescribed. Add to that the fact that supplements are an extremely profitable industry, and you can end up with convincing marketing claims attached to products with very little evidence to back them up.
- Iron if deficient
- Vitamin B12 if deficient
- Vitamin D if deficient
- Magnesium sleep, muscle
- Creatine muscle, strength, cognition
- Phytoestrogens hops, soy, flax
- Vitex PMS, cycle irregularity
- Shatavari mood, hot flushes, libido
- Saffron mood
This is not to say there are no good options out there. There are some supplements with robust evidence behind them, and some companies that put the science front and centre in how they formulate and market their products. The strongest evidence sits with replacing iron, B12, and vitamin D in women who are deficient (which, as the rule-out section earlier in this guide explains, is more common than most women realise), magnesium for sleep and muscle symptoms, and creatine for muscle, strength, and increasingly for some of the cognitive symptoms of perimenopause.
Beyond replacing what is deficient, the natural world offers a few options with real evidence behind them. Phytoestrogens, found in hops, soy, and flaxseed, have reasonable evidence for hot flushes. For the PMS-style symptoms and cycle irregularity of early perimenopause, the strongest evidence sits with vitex (chasteberry). Shatavari, an Ayurvedic herb long used in women's medicine, has smaller but suggestive evidence for mood, hot flushes, and libido. And saffron, increasingly studied, shows emerging evidence for mood.
We have a separate summary of where the evidence sits for the most commonly asked-about supplements. The most important thing is to bring anything you are considering to your doctor first, to check it is appropriate, evidence-based, and not interacting with anything else you are taking. Some supplements have meaningful interactions with prescription medications, and some are not safe in particular health conditions, even though they are sold without a prescription.
Armed With the Why, Now You Can 'Hopefully' Sleep at Night.
Perimenopause is one of the most hormonally complex periods of a woman’s life, not because anything has gone wrong, but because a complicated hormonal system is winding down in its own time and in its own way. The changes are real. The symptoms are real. Now that you understand the physiology behind them, and what the treatment options actually are, you can approach what comes next with clarity and confidence. And hopefully, a little less Googling at 3am.