Menopause is a sudden “cliff”, not a slow decline, major study claims, but experts urge caution

For generations, women have been told that menopause is a gradual winding down. A large new international study suggests it may be closer to falling off a cliff. Australian experts say women shouldn’t be alarmed by that.

The research, published in Nature Medicine, analysed more than 300 million routine lab test results from over a million women in the United States and Israel, collected between 1999 and 2024. The researchers, led by Professor Uri Alon, say they found a sharp, sudden shift in the body’s chemistry around the time of menopause. They’ve described it as a “physiological cliff”.

What the study found

The team tracked 90 common blood and lab markers, the kind measured at a routine GP check-up, and looked at how they changed as women moved through menopause.

Of those 90 tests, 52 showed an abrupt change around menopause instead of a slow, steady drift. The shifts showed up across several body systems, including markers linked to cholesterol, bone health, kidney function and blood sugar.

The researchers also found that hormonal changes start much earlier than many women realise:

• AMH (anti-Müllerian hormone, a marker of egg reserve) began falling about 15 years before menopause.
• Oestradiol, the main form of oestrogen, began declining about 12 years before.
• FSH (follicle-stimulating hormone) began rising about 14 years before.

The study found that women using menopausal hormone therapy (MHT) showed smaller changes in many of these markers. Men of the same age showed no equivalent sudden shift.

The authors argue the findings point to menopause as a key moment for health checks and possible intervention, not just a time for managing symptoms.

“Potentially alarming”: the expert pushback

Not everyone is convinced the “cliff” framing is helpful, or accurate.

Professor Martha Hickey, a menopause specialist at the University of Melbourne and The Women’s Hospital in Victoria, says menopause is “a normal and inevitable life stage”. She warns that describing it as a cliff could be “potentially alarming for women”.

Professor Hickey points out that the study is retrospective and cross-sectional. That means it looked back at existing records instead of following the same women over time, which places it at a relatively low level of scientific evidence.

She also raised several limitations:

• Defining menopause is tricky. Working out exactly when each woman reached menopause from lab records alone is difficult, and errors could distort the timing of the “cliff”.
• Blood tests aren’t random. People usually have tests because a doctor has a reason to order them, so the data may lean towards women who already had health concerns.
• Some findings aren’t new. The link between menopause and bone density loss has been well established for years.
• The MHT finding needs care. Only about 9 per cent of the women were using MHT. Because they weren’t randomly assigned to it, the results could reflect a “healthy user” effect, where women who choose MHT tend to be healthier to begin with.

Professor Hickey notes that randomised controlled trials, the gold standard of medical evidence, don’t support using MHT to prevent heart disease or dementia.

“Hypothesis-generating rather than conclusive”

Professor Andrew Shelling, a reproductive health researcher at the University of Auckland, welcomed the attention on a topic he says remains “relatively understudied and poorly understood”.

He agreed, though, that the results should be “viewed as hypothesis-generating rather than conclusive”. In other words, the study raises questions for further research but doesn’t settle them.

He also noted that MHT is most effective for treating hot flushes and night sweats, and that its role in long-term disease prevention remains unproven.

A workplace angle

Professor Rebecca Mitchell, Director of the MQ Health at Work Research Centre at Macquarie University, says the findings are a reminder that menopause doesn’t just happen to women in their 50s.

About 40 per cent of women reach menopause in their 40s, she says, and perimenopause can begin as early as the mid-to-late 30s. That often overlaps with the years when women are going for promotions and leadership roles. She says workplaces need to recognise this and offer support, so women aren’t quietly disadvantaged during a key stage of their careers.

What it means for you

If you’ve already been through menopause, this study doesn’t mean something has gone wrong. The changes it describes are a normal part of ageing.

It is a useful reminder, though, that the years around and after menopause are a good time to keep on top of your health. That includes regular checks of cholesterol, blood pressure, blood sugar and bone density. If you have questions about MHT, including whether it’s right for you, talk to your GP or a menopause specialist. They can weigh up the benefits and risks for your own circumstances.

This article reports on research published in Nature Medicine and is general in nature. It isn’t a substitute for personalised medical advice. Please speak to your GP or a qualified health professional about your own health.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.