Is there an ideal age to start HRT?
Nick Panay, professor of practice at Imperial College London and immediate past president of the International Menopause Society (IMS), is a leading advocate of the so-called “window of opportunity” approach to HRT.
The theory is that, for most women, the balance of risks and benefits is most favourable when treatment is started “typically before the age of 60 years, or within 10 years of the menopause transition”, Panay says.
If someone reaches menopause at the average age of 51, the 10-year postmenopausal window would take them to 61. However, for women who reach menopause earlier or later, the window shifts accordingly.
Dr Naomi Potter, the British Menopause Society-accredited founder of Menopause Care, stresses that 10 years is not a hard cut-off. “Care should always be tailored to the individual,” she says. “It’s about assessing each woman’s balance of risk and benefit.”
Can you start treatment too early?
While menopause is defined as 12 months without a period, perimenopause is far less straightforward. The transition before menopause, when hormones fluctuate, fertility declines and menstrual cycles become less predictable, typically begins in the mid to late 40s.
“For women with symptoms which are having a negative impact on their lives, HRT can make a vast difference,” says Potter.
A change in menstrual patterns is usually the most reliable indicator that you are in perimenopause, according to Kathy Abernethy, director of clinical practice at the British Menopause Society (BMS).
During this time, “HRT can eliminate hot flushes and sweats, and help with vaginal dryness,” she says. “It can sometimes help with emotional symptoms and brain fog, too, but not always, as there are often other factors contributing to those, such as stress.”
As a result, it can be difficult to know which symptoms are hormonal, particularly when perimenopause is now the subject of seemingly endless celebrity interviews and discussion on social media. “The downside of the coverage is that there are probably women on HRT unnecessarily now, who think they are in perimenopause but possibly aren’t,” says Potter.
In some cases, she adds, taking HRT when symptoms are not hormonal can actually make a woman feel worse. That’s why both experts state that other potential causes of symptoms should always be considered carefully first.
If you do decide to start treatment, they emphasise that there is no single perfect moment. “The timing is very fluid and for healthy perimenopausal women, HRT is an extremely safe medication,” says Potter.
When the timing truly matters
For women in perimenopause and around the time of menopause, the primary benefit of HRT lies in managing debilitating symptoms. But there are also longer-term health benefits, particularly for bone health and the cardiovascular system – and timing appears to matter.
Cardiovascular health is one area where there seems to be an optimal window. The IMS’s latest recommendations, published earlier this year after a systematic review of the evidence, report that there is strong and consistent evidence that HRT is cardioprotective – meaning it can help to protect the heart from damage, disease or stress – when started around the time of menopause. However, the same benefit has not been demonstrated when treatment begins more than 10 years later.
“Oestrogen has a protective effect on the cardiovascular system, but if the gap without oestrogen lengthens, the cardiovascular benefits of starting HRT become less clear,” says Potter.
The recommendations also highlight evidence that HRT can reduce bone loss and fracture risk, with the benefits particularly apparent when started around the time of menopause.
For women who go through menopause unusually early, timing seems to be particularly important. Those with premature ovarian insufficiency (before 40) or early menopause (before 45) have “maximum long-term health benefits” from taking hormone replacement until around the average age of natural menopause, according to Professor Panay.
“In this age group there are cognitive benefits, as well as benefits for bone and cardiometabolic health,” he says.
Do the risks change at different ages?
As women get older, the balance of risks and benefits needs to be reassessed.
“The risks of thrombosis and stroke increase with age, especially over 60, and particularly with oral oestrogen-containing HRT,” says Panay. Oral oestrogen, taken as pills, is processed by the liver, which can increase clotting activity in the blood. For women starting HRT later in life, Panay recommends considering a lower dose, with oestrogen delivered transdermally via a patch, gel or spray, alongside progesterone, such as Utrogestan, to protect the womb lining.
“Transdermal oestrogen does not increase the risk of blood clots,” explains Potter, who adds that oral oestrogen is still “very safe” for women at low risk of thrombosis.
Meanwhile, the risk of breast cancer appears to be more closely related to the type and duration of HRT than simply a woman’s age. the NHS puts the overall risk at about five extra cases of breast cancer in every 1000 women who take combined HRT for five years. The risk is thought to increase the longer HRT is taken, but it depends on an individual’s genetics and modifiable risk factors, such as BMI and exercise levels.
During perimenopause, Potter frequently recommends getting a Mirena coil fitted, too, to provide the progestogen needed to protect the womb lining, as well as contraception. “If it suits you, it can be a really useful part of HRT,” she says. “It can be brilliant for endometrial protection and means you don’t have to think about taking an additional progesterone.” It must be changed every five years to keep the lining of the womb healthy, but it can stay in place until the age of 55.
Most HRT prescribed in Britain is bio-identical, which refers to hormones in the HRT being chemically identical to those your body produces. There are occasions when synthetic progesterone is recommended instead of Utrogestan, but these are not age-related.
Is it ever too late to start taking HRT?
Many women now in their 60s avoided HRT because of the breast cancer scare that followed the 2002 Women’s Health Initiative study. Subsequent research has painted a more nuanced picture of the risks, and Abernethy says that women who wish to begin treatment now haven’t necessarily missed their “window”.
“It may be too late for some benefits, but not all,” she says. “Some women continue to experience symptoms such as hot flushes and night sweats for many years after menopause, and HRT may still give them significant relief.”
There may also be benefits for vaginal and bladder health, as well as protection against bone loss for women starting treatment later.
Potter is similarly reluctant to impose an age cut-off. “I never say never to anybody,” she says. “I always discuss a patient’s individual health, symptoms and risk factors.”
She adds that vaginal oestrogen, applied locally to relieve symptoms such as dryness, irritation and frequent urinary tract infections, has not been shown to increase breast cancer risk and should be offered to women of any age, from perimenopause onwards.
The decision to stop taking HRT should be up to the individual, too, says Abernethy. “It’s vital to have regular reviews with patients to discuss their symptoms, risk factors and needs, but there’s no upper age limit, and they don’t have to stop just because they’ve been on it a certain length of time,” she says.
Why the tailored approach is best
There is no magic age at which women should begin or stop HRT. For some, the strongest evidence of its long-term benefits is when treatment begins around menopause or within 10 years afterwards, but women who start later may still benefit, particularly if they have distressing symptoms.
For me, the improvement in my migraines and energy suggests that, at 45, HRT was the right decision, but as Potter says, “every woman’s menopause is different.”
