HRT patches and tablets can both be part of menopause care, but the way oestrogen enters the body matters. The clearest difference concerns blood clots, rather than a promise that one route protects the ageing brain. Choosing between them means considering symptoms, medical history, and the rest of the prescription. The NHS guide to HRT types makes that individual assessment the starting point.
First separate the route from the hormones
“HRT” describes several treatments, not one interchangeable medicine. A prescription can contain oestrogen alone or oestrogen with a progestogen. It can also follow a cyclical or continuous schedule. Those are different questions from whether the oestrogen is swallowed or absorbed through the skin. As the NHS explains, the choice depends partly on menopause stage and whether someone has had a hysterectomy.
A useful way to read a prescription is therefore to ask three questions: which hormones does it supply, how are they delivered, and when are they used? A patch does not, by its appearance, answer all three. Nor does the word “tablet” tell you whether you are looking at oestrogen or another part of the treatment. Asking a pharmacist to explain the complete prescription is more useful than comparing two product names online.
This article concerns systemic treatment: hormones intended to act throughout the body. Low-dose vaginal oestrogen is a separate treatment for local symptoms, with much less absorption into the rest of the body. The NHS benefits and risks guide distinguishes it from systemic HRT. A discussion about tablets versus patches should not obscure that difference.
Why the route changes the clot discussion
Swallowed oestrogen passes through the liver before reaching the wider circulation. Oestrogen delivered through the skin avoids that initial passage. This matters because oral oestrogen can change the production of proteins involved in clotting. The 2025 European Society of Endocrinology guideline describes this mechanism and the clinical evidence linking oral treatment to higher venous clot risk.
Mechanism alone would not settle the question. We also need evidence about people who actually develop clots. In Yana Vinogradova and colleagues’ 2019 BMJ study, researchers used two UK primary-care databases to compare women with venous thromboembolism with matched controls. Oral HRT was associated with higher odds of a clot; transdermal treatment was not associated with an increase. “Transdermal” means delivered through the skin.
This was an observational study, rather than a trial randomly assigning routes. Its findings are clinically useful, but they do not guarantee the outcome for an individual. The distinction is especially important when someone already has reasons to be at increased risk: choosing a route cannot erase their underlying medical history.
Read risk figures with their denominator attached
The BMJ study reported an adjusted odds ratio of 1.58 for oral HRT compared with no HRT use in the previous year. That does not mean 58 out of every 100 users developed a clot. Across the studied age range, the researchers estimated approximately nine additional cases per 10,000 women over a year of oral HRT use. The estimate varied with age and preparation. These are population findings from the 2019 study, not a personal forecast.
Both ways of expressing risk matter. A relative increase can sound large while the absolute number remains small; a small average increase can still matter to someone whose starting risk is higher. When discussing a prescription, it is reasonable to ask what the comparison means for people with a similar age and history, over a stated period.
Current NICE menopause guidance advises clinicians to consider transdermal rather than oral HRT for people at increased risk of venous thromboembolism, including those with a BMI above 30. That recommendation helps inform a consultation. It is not a screening rule that allows readers to decide independently that either route is appropriate.
A patch does not replace the rest of the assessment
Someone with a womb generally needs a progestogen alongside systemic oestrogen to protect the womb lining. Changing from oral oestrogen to a skin preparation does not remove that requirement. The NHS suitability guidance makes this explicit. An oestrogen-only patch should never be assumed to supply a complete combined prescription.
The same guidance identifies histories that need discussion before treatment, including breast cancer, unexplained vaginal bleeding, previous venous clots, thrombophilia, heart attack or angina, and liver problems. Migraine, diabetes, and high blood pressure also need to be disclosed. These conditions do not all mean the same thing or create the same restriction; the purpose of reporting them is to allow a clinician to assess their significance.
In particular, a previous clot is not a reason to switch yourself to a patch and consider the matter resolved. The European endocrine guideline describes this as a complex decision requiring individual assessment and expert input. Similarly, a favourable clot profile cannot be used as evidence that breast-cancer or other treatment risks have disappeared.
Comfort, side effects, and the aim of treatment
For some people, a daily tablet fits an established routine. Others prefer a patch. Adhesion problems or skin irritation can make patches inconvenient, according to the NHS comparison of formulations. These practical details belong in the decision alongside medical risk. A technically suitable prescription still needs to be workable in ordinary life.
Headaches, breast tenderness, nausea, mood changes, and unexpected spotting can occur with HRT. The NHS side-effects guidance says a GP may consider changing the dose, formulation, or route when problems arise. It advises speaking to a GP about severe side effects or those continuing beyond three months. That is not a reason to wait three months before reporting a worrying symptom.
A review can begin with what treatment was meant to improve and what has actually changed. “I am sleeping better but the patch irritates my skin” is more useful information than a general judgement that the product is good or bad. The NHS guide to starting HRT emphasises that treatment is a choice made with an explanation of benefits and risks; symptoms need not become severe before that conversation happens.
What this means in practice
- Bring the names and schedules of every part of an existing HRT prescription to a review. Ask which supplies oestrogen and which, if needed, protects the womb.
- Write down the symptoms you want help with and any changes since treatment began. Include side effects and practical problems with the formulation.
- Tell the prescriber about previous clots, cancer, unexplained bleeding, liver or cardiovascular disease, migraine, and other medicines. Ask whether specialist input is needed.
- When discussing clot risk, ask for an absolute estimate over a stated period, as well as any relative comparison. Check which age group and preparation the estimate describes.
- Discuss any proposed route change with the prescriber or pharmacist, including the complete regimen. Do not assume a different oestrogen product replaces every component.
These are ways to prepare for shared decision-making, rather than instructions to start or alter treatment. They reflect the assessment and review approach in the European endocrine guideline.
What we don’t know
Large observational datasets cannot fully remove differences between the people prescribed tablets and those prescribed skin preparations. Prescription records also cannot prove exactly how medicines were used. The BMJ study’s design and limitations matter when interpreting its route comparisons. More precise claims about every dose, formulation, and individual would go beyond what those data establish.
Nor does a lower observed clot risk establish that a route prevents dementia or slows brain ageing. The NHS says it is not known whether HRT reduces dementia risk. Brain health deserves careful research, but it should not become a promise attached to a patch prescription.
The route is a meaningful part of the HRT decision. A useful consultation keeps it connected to the treatment goal, the full prescription, and the person who will use it.
Photo: SHVETS production on Pexels. Illustrative medication photograph; the tablets shown are not identified as HRT.
