Hormone therapy has its most favourable balance of benefit and risk when it is started before age 60, or within ten years of your final period. In the guides we publish here, this boundary generates more confusion than any other number in menopause care, because it is regularly reported as a deadline after which treatment becomes unavailable.
It is not a deadline. It marks where the calculation shifts, and the shift is driven by background risk rising with age rather than by hormone therapy becoming a different drug.
The Menopause Society 2022 hormone therapy position statement is the source of the boundary, and it is the document most clinicians in the United States work from.
The Verdict
The Window the Guidelines Define
Four situations cover almost everyone asking about timing, and only two of them are governed by the ten-year boundary at all.
| Your situation | What it is prescribed for | What the guidance says | What that means in practice |
|---|---|---|---|
| Under 60, and within 10 years of the final period | Bothersome hot flushes and night sweats, or bone loss prevention | The Menopause Society describes the benefit-risk balance as favourable in this group with no contraindications | This is the standard case, and it covers most women asking the question |
| Over 60, or more than 10 years past the final period | Symptoms that persist, or that returned after stopping | The balance is described as less favourable, because absolute risks of coronary heart disease, stroke and venous thromboembolism are higher at older ages | Not a prohibition. It shifts the conversation toward the lowest effective dose and the transdermal route |
| Premature ovarian insufficiency, or menopause before 45 | Any symptoms, and long-term bone and cardiovascular protection | Hormone therapy is generally recommended at least until the average age of natural menopause, around 51 to 52 | The risk framing from older women does not transfer here. Withholding it has its own costs |
| Genitourinary symptoms only | Vaginal dryness, painful sex, recurrent urinary symptoms | Low-dose vaginal oestrogen is a local treatment with minimal systemic absorption | The timing window does not apply. It can be started at any age, including alongside or instead of systemic therapy |
Rows three and four are the ones most often missed. Women with premature ovarian insufficiency are treated on entirely different reasoning: they are replacing hormones their age group would normally have, and the risk framing developed for 65-year-olds does not transfer to them. Low-dose vaginal oestrogen sits outside the window altogether because systemic absorption is minimal.
Why the Timing Changes the Risk
Two separate things move with age, and the guideline boundary reflects both.
The first is background risk. Coronary heart disease, stroke and venous thromboembolism all become more common as women get older, independently of any treatment. A given relative risk applied to a larger baseline produces a larger absolute number of events, which is why the same percentage reads differently at 52 and at 68.
The second is the timing hypothesis. It proposes that oestrogen acts differently on arteries that are still relatively healthy than on arteries already carrying atherosclerotic plaque. Reanalysis of the Women's Health Initiative by age at initiation, and subsequent trials in recently menopausal women, support it. It remains a hypothesis rather than a settled mechanism.
Our page on HRT side effects and risks covers what those trials found in absolute numbers, which is the format that makes the age difference legible.
Starting in Perimenopause Rather Than After
Symptoms usually begin before periods stop. Hot flushes, sleep disruption and mood changes are common in perimenopause, and treatment does not require waiting for twelve consecutive missed periods to confirm the diagnosis.
One practical difference applies. Ovulation can still occur in perimenopause, and standard hormone therapy is not a contraceptive. Anyone who could become pregnant needs contraception alongside it, and for some women a combined hormonal contraceptive handles symptoms and contraception together, which is worth raising rather than assuming.
Hormone levels are not required for the diagnosis in most women over 45, and they fluctuate widely enough during perimenopause that a single result can mislead in either direction. Our page on the perimenopause biomarker panel covers where testing does add information and the cycle-day timing that makes each result interpretable. Our guide to the three stages of menopause covers how to work out where you are.
When to Stop, and Whether There Is a Limit
No fixed duration applies. The Menopause Society position moved away from arbitrary stopping rules toward periodic reassessment, which in practice means an annual conversation covering three questions.
- Would symptoms return if the dose came down? The usual way to find out is to lower it and see, rather than to stop outright.
- Has anything changed in your risk profile? A new cardiovascular event, a clot, or a breast cancer diagnosis all change the calculation.
- Do you still want to be on it? Preference is a legitimate input, and it changes over time.
Where you do stop, tapering across several months is generally better tolerated than stopping in one step, because abrupt withdrawal often brings vasomotor symptoms back sharply. Vaginal oestrogen for genitourinary symptoms is frequently continued after systemic therapy ends, since it treats a problem that does not resolve on its own and does not carry the same systemic considerations.
Where the Window Does Not Apply
Two situations run on separate rules, and applying the standard timing advice to them produces the wrong answer.
- Menopause before 45, whether spontaneous or surgical. Hormone therapy is generally recommended at least until the average age of natural menopause, because the comparison group is women of the same age who still have ovarian function. Withholding it carries bone and cardiovascular costs of its own.
- Genitourinary symptoms treated locally. Low-dose vaginal oestrogen has minimal systemic absorption, so the systemic risk framing does not apply. It can be started at any age and continued indefinitely.
Who Should Not Start at All
Four groups have contraindications that hold regardless of timing.
- Anyone with a history of oestrogen-receptor-positive breast cancer. Systemic hormone therapy is generally avoided, and non-hormonal options exist.
- Anyone with unexplained vaginal bleeding. That needs investigating before any hormone treatment starts.
- Anyone with a personal history of venous thromboembolism or stroke. This shifts the discussion decisively, and where treatment does go ahead it is transdermal.
- Anyone with active liver disease. Oral oestrogen in particular is metabolised through the liver on first pass.
Our reading of the ten-year boundary would change if a large randomised trial initiated hormone therapy in women over 60 with cardiovascular endpoints and adequate power. The current evidence for the older group leans heavily on subgroup analysis of trials designed to answer a different question, which is a weaker foundation than the boundary's confident repetition suggests. A purpose-built trial would either firm it up or move it.
Work out how many years it has been since your final period, then book the conversation with a prescriber while that number still puts you inside the window.
Frequently Asked Questions
When should you start menopause hormone therapy?
The favourable window is being under 60 or within ten years of your final period, with bothersome symptoms and no contraindications. The Menopause Society 2022 position statement sets that boundary, and it is the reference most clinicians work from. Within that window there is no advantage to waiting: symptoms are usually worst in the first few years after the final period, which is exactly when treatment is both most effective and lowest risk.
Can you start HRT after 60?
It is not prohibited, and the balance is less favourable. Absolute risks of coronary heart disease, stroke and venous thromboembolism rise with age regardless of hormone therapy, so the same relative risk translates into a larger absolute number. Starting after 60 generally means the lowest effective dose and a transdermal route rather than oral. Persistent severe symptoms are a legitimate reason to have the conversation, and it is a more individual decision than it is inside the window.
Can you start HRT during perimenopause?
Yes, and many women do. Symptoms frequently begin in perimenopause, years before periods stop, and treatment does not require waiting for twelve consecutive missed periods. What differs is that cycles may still occur, so contraception remains necessary if pregnancy is possible, and standard hormone therapy is not a contraceptive. Some women in perimenopause are better served by a combined hormonal contraceptive that handles both jobs, which is a discussion for a prescriber.
How long can you stay on hormone therapy?
No arbitrary duration limit applies. The Menopause Society position statement moved away from fixed stopping rules toward periodic reassessment of benefits and risks. In practice that means an annual conversation about whether symptoms would return, what your risk profile now looks like, and whether the dose is still right. Some women stop after two years, some continue for a decade or longer, and both can be appropriate decisions made on the same framework.
When should you stop HRT?
There is no age at which stopping becomes mandatory. The trigger is usually a change in the balance: symptoms no longer returning when the dose is lowered, a new contraindication appearing, or a shift in your own preference. Where you do stop, tapering over several months is generally better tolerated than stopping abruptly, because abrupt withdrawal frequently brings symptoms back sharply. Vaginal oestrogen for genitourinary symptoms is often continued after systemic therapy ends.
What is the timing hypothesis?
The timing hypothesis proposes that hormone therapy started close to menopause has a different cardiovascular effect than the same treatment started a decade later, because arteries that are already atherosclerotic respond differently to oestrogen than healthy ones do. It emerged from reanalysis of the Women’s Health Initiative by age group and from subsequent trials. It is the reasoning behind the ten-year boundary, and it remains a hypothesis with supportive rather than definitive evidence.
Do I need blood tests before starting hormone therapy?
Hormone levels are not required to diagnose menopause in most women over 45, where the diagnosis is made on symptoms and cycle history. Levels fluctuate widely in perimenopause, so a single FSH or oestradiol result can mislead. What is worth checking before starting is the risk side: blood pressure, lipids and any personal or family history relevant to clotting or breast cancer. Our perimenopause biomarker panel page covers when hormone testing does add something.
Is it too late to start HRT if I stopped years ago?
Restarting after a gap puts you back into the same framework, judged on your current age and time since your final period rather than on when you first took it. Someone who stopped at 54 and wants to restart at 57 is still inside the standard window. Someone restarting at 64 is in the less favourable group and the conversation shifts toward the lowest effective dose. Either way it is a discussion with a prescriber rather than a door that closed.
Related
- HRT side effects and risks: the absolute numbers
- Hormone therapy platforms compared: the providers on one rubric
- HRT cost: what each access route charges
- The three stages of menopause: working out where you are
- Perimenopause biomarker panel: when testing helps
- HRT vs bioidentical hormone therapy: what compounding changes
- HRT and weight gain: what the trials found