I finally understand my therapy. The app reminds me, answers my questions — and I don't feel alone with it anymore.
Estradiol
Estradiol: Patch or Tablet — the Thrombosis Difference in Hormone Therapy
Estradiol is the body's own oestrogen and the active ingredient in most hormone replacement therapies during the menopause. It relieves hot flushes, sleep problems and vaginal dryness and protects the bones. Whether it is swallowed as a tablet or absorbed through the skin makes a measurable difference to the risk of thrombosis — but not to the risk of breast cancer.
Estradiol (as estradiol hemihydrate or estradiol valerate); chemically identical to the oestrogen produced by the ovaries
ATC code
G03CA03
Drug class
Natural oestrogen, sex hormone
Dosage forms
Tablets, transdermal patches (changed once or twice a week), gel, spray; low-dose vaginal forms for local treatment
Half-life
Tablets: because it is converted into oestrone and back again, the effect lasts about a day; patches: after removal, the level falls back to baseline within about 12 hours according to the SmPC
Maximum daily dose
Orally in hormone replacement therapy usually 1 to 2 mg; patches release 25 to a maximum of 100 micrograms per 24 hours. The principle: the lowest effective dose, set by the practice
Onset of effect
Hot flushes often improve after 2 to 4 weeks, full effect after about 3 months
Prescription status
Prescription-only medicine
Notable feature
Women who still have a uterus also need a progestogen. Given through the skin, estradiol raises the risk of thrombosis considerably less than in tablet form, according to current knowledge
Table scrolls to the right
2. How it works: why the route into the body matters
During the menopause, the ovaries gradually stop producing oestrogen. The body reacts in many places at once: the temperature centre in the brain becomes oversensitive and sets off hot flushes and night sweats, the mucous membranes in the intimate area become thinner, and bone loss speeds up. Estradiol replaces the missing hormone — and it is exactly the same molecule the body used to make itself.¹
That is where its strengths come from: according to current evidence, oestrogen is the most effective treatment available for hot flushes; sleep and vaginal dryness often improve along with them, and for as long as estradiol is used, it slows down bone loss.² The typical side effects follow from the same principle: oestrogen acts on the breasts and on the lining of the womb — breast tenderness and bleeding are common, and without a counterpart the lining builds up unchecked.
The detour through the liver
The decisive difference between the dosage forms lies not in the active ingredient but in the route. A tablet is absorbed in the gut and passes through the liver first, before it reaches the rest of the body (first-pass effect). In the process the liver is exposed to a high concentration of oestrogen and responds: it makes more clotting factors, more transport proteins and more triglycerides. This increased readiness to clot is the most plausible explanation for why oral oestrogens raise the risk of blood clots.
A patch, gel or spray, by contrast, delivers estradiol through the skin straight into the blood (transdermally). The liver only sees the amount that is in circulation anyway — much as with the body's own hormone production before the menopause.¹ What that means for the risk of thrombosis is explained in section 6.
Important for perspective. Estradiol treats symptoms, not a disease. Hormone therapy makes sense when the symptoms noticeably limit your quality of life. The guide hormone replacement therapy gives an overview of the benefits and risks of hormone therapy as a whole — this article concentrates on the active ingredient estradiol and on the question of the dosage form.
3. Dosing: tablet, patch, gel and spray
The following information describes what the SmPCs give as the usual approach. It is not a dosing instruction — which form and dose suit you is decided by the treating practice together with you.¹
The principle of the lowest effective dose: the SmPC and the guideline require treatment to start with the lowest dose that relieves the symptoms sufficiently, and benefits and risks to be weighed up again at least once a year.
Tablets: once a day, in hormone replacement therapy usually 1 to 2 mg — simple, but with the detour through the liver.
Patches: changed twice or once a week depending on the product, with an even release of 25 to 100 micrograms per 24 hours. According to the SmPC, 100 micrograms per day should not be exceeded.
Gel and spray: applied daily to a defined area of skin; the dose can be finely adjusted, but the routine is more demanding.
Vaginal products: very low-dose, they act mainly locally against vaginal dryness. They are not systemic hormone therapy and are assessed differently.
The progestogen is part of it
Women who still have a uterus also need a progestogen — on at least 12 to 14 days a month (sequentially, usually with a monthly withdrawal bleed) or every day (continuous combined). Without this protection, the risk of thickening of the womb lining and of womb cancer rises considerably.¹ Options include tablets, for example with micronised progesterone, combination patches or a hormonal coil. After a hysterectomy, a progestogen is usually not needed.
The commonest gap in everyday life. If you use estradiol as a patch or gel and the progestogen as a tablet, you have two separate products with different rhythms. This is exactly where something gets forgotten most often — and missed progestogen days are not a comfort problem but a safety problem for the lining of the womb. Both belong in your medication plan, with their schedule.
4. Using it in everyday life
You take tablets every day at roughly the same time, with or without a meal. The patch calls for a little more attention — but only once or twice a week.
Choose fixed change days, for example Monday and Thursday. Forgotten? Put the new patch on as soon as you notice, then go back to your usual days. Forgotten patches can trigger spotting.¹
The right spot: below the waist, for example the upper buttock area, the hip or the lower abdomen — never on or near the breasts. The skin should be clean, dry, undamaged and free of cream.
Press down and rotate: press down with the flat of your hand for at least 30 seconds, and put each new patch in a different place.
If it comes loose: a partly detached patch is replaced and the change rhythm stays the same. Used patches still contain active ingredient: fold them with the sticky sides together and dispose of them out of the reach of children.
Gel and spray: the transfer trap
Gel and spray dry on the skin before the active ingredient has been fully absorbed. During that time, estradiol can pass to other people through close skin contact — in children, this can lead to premature breast development. Wash your hands after applying it, let the area dry and cover it.
Two rhythms, one plan. Patch on Monday and Thursday, progesterone in the evening on days 1 to 12 or 14 of the month, plus a bleeding calendar: that is exactly the kind of schedule that goes wrong when you keep it in your head. A reminder takes over the arithmetic — and records along the way whether the hot flushes really are becoming less frequent.
Count your hot flushes instead of guessing
A symptom history shows at your next appointment whether the dose is right — or whether less would do.
5. Side effects: what is common and what is serious
Most side effects appear in the first few weeks and ease off afterwards. Many of them point to a dose that is slightly too high — a reason to talk, not to stop quietly.¹
Common and usually temporary
Breast tenderness: very typical at the start and after dose increases. If it persists, it can be a sign that the dose is too high.
Bleeding: spotting and breakthrough bleeding are common in the first few months. If they appear for the first time later on, or continue after the end of treatment, they must be investigated — more under bleeding between periods.
Headaches, nausea, fluid retention: nausea tends to be a problem with the tablet.
Skin reactions: redness and itching where the patch is stuck are the typical patch side effect. Consistent rotation helps; otherwise a different patch or a gel may suit you better.
Mood swings: often more attributable to the progestogen component — a symptom diary helps to tell the phases apart.
Rare but serious
The rare, serious risks include blood clots in the veins (venous thromboembolism), stroke, gallstones and, with long-term use, an increased risk of breast cancer. The risk of womb cancer rises if women with a uterus do not receive an adequate progestogen.¹,² The absolute risks depend heavily on age, when treatment was started, weight, pre-existing conditions and the duration of treatment — and, in the case of thrombosis risk, on the dosage form as well.
Warning signs of thrombosis, pulmonary embolism and stroke. A painful swelling of one leg, often with a feeling of tightness or pain in the calf, sudden shortness of breath, stabbing chest pain or coughing up blood, as well as sudden paralysis or a sudden disturbance of speech or vision: call 112 (emergency number in Germany) immediately. In that case, estradiol is not used any further until a doctor has clarified what is going on. Background under thrombosis and pulmonary embolism.
According to the SmPC, treatment must also be stopped if jaundice develops, blood pressure rises significantly, migraine-type headaches occur for the first time or a pregnancy occurs.¹
6. The thrombosis difference: patch or tablet
This is the heart of this article. That hormone therapy raises the risk of blood clots has been known for a long time; for hormone replacement therapy as a whole, the SmPC gives a 1.3- to 3-fold increased risk, highest in the first year of use.¹ This statement is a class warning that applies to all products — patches included. Research over the last twenty years has, however, refined the picture considerably.
What the studies show
The French ESTHER study compared women with and without venous thrombosis: oral oestrogen was associated with a clearly increased risk of thrombosis, transdermal oestrogen was not.³ Large British analyses of GP practice databases reached the same result — transdermal products showed no increased risk compared with women not taking hormone therapy.⁴ Both also suggest that the choice of progestogen plays a part: micronised progesterone and dydrogesterone came out better than some other progestogens.
The German S3 guideline on the peri- and postmenopause follows this line: women should be informed that the risk of thromboembolism is increased on oral oestrogen therapy and is higher than with transdermal use. The draft of the updated version puts it even more clearly: the risk of thrombosis and stroke is distinctly higher on oral oestrogen than on transdermal oestrogen, and it increases with the dose.²
How robust is this? The data come mainly from observational studies, not from large randomised comparative trials. Such studies can contain biases — for example because women with a known risk are more often prescribed a patch. But the fact that the results come out the same in several large, independent datasets and fit the biological mechanism makes them convincing according to current knowledge. Honestly put, this means: where the risk of thrombosis is concerned, the patch is very probably the safer choice — it has not been proven to be "risk-free".
Aspect
Tablet (oral)
Patch, gel, spray (transdermal)
Route into the body
Via the gut and liver (first pass)
Through the skin straight into the blood
Clotting factors from the liver
Produced in greater amounts
Hardly affected
Thrombosis risk in studies
Increased, dose-dependent, especially in the first year
Not detectably increased at usual doses in observational studies
Stroke risk
Slightly increased
Probably not increased at low doses, on current data
Triglycerides, gallstones
Rather unfavourable
More neutral
Breast cancer risk
Increased with longer use
Equally increased — the route makes no difference
Progestogen if you have a uterus
Needed
Equally needed
Everyday life
Simple, one tablet a day
Skin irritation, coming loose; with gel, drying time and risk of transfer
Table scrolls to the right
Who the difference matters most for
For a healthy woman of normal weight in her early fifties, the absolute risk of thrombosis is low even with a tablet. The difference becomes relevant when further risk factors come together — according to the SmPC and the guideline, for example marked overweight (BMI over 30), older age, thromboses in close relatives, smoking, high blood pressure, diabetes, migraine with aura, gallstones, raised triglycerides, and planned operations or foreseeably long periods of immobility.¹,²
What the patch does not change
Three points are often overlooked in the patch debate. First: the risk of breast cancer depends on the duration of treatment and on the progestogen component, not on the route of the oestrogen. A large analysis of all the observational data available worldwide found a comparable risk for oral and transdermal oestrogen.⁵ Second: a previous thrombosis or pulmonary embolism and known severe clotting disorders are a contraindication for patches too, according to the SmPC. Whether transdermal treatment might nevertheless be considered in such a situation in an individual case is a specialist decision — not something to try out yourself. Third: the progestogen remains necessary, and the choice of progestogen also influences the overall risk.
The question for your next appointment. "Which dosage form is the safest for my personal risk profile — and which progestogen goes with it?" Bring an up-to-date list of your medicines and make a note beforehand of any thromboses in the family, migraine and your weight. The decision is made by the practice together with you; switching from tablet to patch is not something you do on your own.
7. Interactions
Estradiol is broken down in the liver, mainly via enzymes of the cytochrome P450 family. Medicines that rev up these enzymes can weaken its effect. Conversely, estradiol itself affects some other active ingredients — the most important are lamotrigine and thyroid hormones.¹
Combination
Consequence
What to do
Enzyme inducers such as carbamazepine, phenytoin, phenobarbital, rifampicin, some HIV medicines
Oral oestrogen raises the transport protein TBG; some women then need more thyroid hormone
Have your TSH checked a few weeks after starting or switching
Hormonal contraception containing oestrogen
A double dose of oestrogen, higher risk of thrombosis
Do not use both at the same time; plan the transition with your doctor
Alcohol
Can raise oestrogen levels; regular drinking increases the risk of breast cancer independently of this
Go easy on alcohol
Table scrolls to the right
The thyroid interaction shows the difference between the dosage forms: because the effect runs through the liver, it mainly concerns the tablet. If you take levothyroxine and start oral hormone therapy, do not leave the next TSH check to chance. A look at your complete list is particularly worthwhile with epilepsy, tuberculosis or HIV treatment and with herbal remedies. The interaction check shows combinations that do not stand out in any single package leaflet.
8. Check-ups, alternatives and stopping
What is checked regularly
An annual weighing of benefits and risks: the SmPC provides for reassessing at least once a year whether the treatment is still needed and at what dose.¹
Blood pressure and breasts: a marked rise in blood pressure is a reason for a review. Watch for breast changes yourself and have mammograms in line with the usual screening rules — hormone therapy can make breast tissue denser.
Hormone levels: as a rule, the dose is guided by your symptoms, not by laboratory values.
Alternatives if estradiol is not right for you
If there are contraindications, or if you do not want hormones, there are non-hormonal options: certain antidepressants, newer active ingredients that act on the temperature centre, and cognitive behavioural approaches. On average they work less well against hot flushes than oestrogen, but they suit some women better.²,⁶ Herbal products show inconsistent results. There are dedicated medicines for osteoporosis; according to the SmPC, estradiol is only licensed for preventing it when these are not an option.
Stopping: no withdrawal, but a plan
Estradiol does not cause a dangerous discontinuation syndrome. The original symptoms can come back, though — hardly at all in some women, clearly in others. Whether tapering off or stopping directly is better cannot be answered clearly from the studies; many women find the gradual approach more comfortable. The protection of the bones ends with the treatment. Plan stopping with your practice, with a symptom record before and after.
9. Special situations: age, surgery, migraine, liver
Pregnancy and breastfeeding: estradiol for hormone replacement therapy is not indicated here; if a pregnancy occurs, treatment is stopped. A pregnancy is still possible in the perimenopause — hormone replacement therapy is not contraception.
Starting after 60 or long after the menopause: cardiovascular and stroke risks rise with age; according to the SmPC, there is evidence of an increased risk of dementia when treatment is started after the age of 65.¹ This calls for a particularly careful weighing-up.
Early menopause: if it begins well before the age of 40 or 45, the guideline generally recommends hormone therapy up to the average age of menopause.²
Surgery and immobilisation: if a longer period of immobilisation is expected after a planned operation, the SmPC recommends interrupting treatment 4 to 6 weeks beforehand.¹ Details in the guide medications before surgery.
Migraine: with known migraine, a transdermal, steady delivery is preferred. Newly occurring migraine-type headaches are a reason to stop treatment and see a doctor.
Liver and gallbladder: acute liver disease is a contraindication. With gallstones or raised triglycerides, the absence of the liver detour tends to favour the transdermal form.
Estradiol is also used in gender-affirming hormone therapy; separate guidelines apply there. This article refers to its use in the menopause.
10. Estradiol experiences: what patients really ask
"My patch keeps coming off — is it even working?"
A patch that is only hanging on by one corner no longer delivers a reliable dose — it is replaced, and the change rhythm stays the same. Common causes of poor adhesion are body lotion, shower gel residue, sweat and rubbing at the waistband. If that does not help, there are products with a different adhesive matrix, or the gel. Patches that are lost again and again create gaps in the supply of the active ingredient, which make themselves felt as hot flushes or spotting — note down those days so that the practice can see the pattern.
"My sister had a thrombosis. Can I still take hormones?"
That depends on the overall picture — and it is exactly the situation in which the dosage form can make the difference. A thrombosis in a first-degree relative at a young age can be a reason to talk about testing for inherited clotting disorders; such a test, however, only picks up some of the causes. If a severe clotting disorder is found, hormone therapy is not indicated according to the SmPC. Without such a finding, a transdermal form with a favourable progestogen tends to be chosen when there is a family history, according to current knowledge. The decision belongs in the gynaecology consultation.
"How long am I actually allowed to take estradiol?"
There is no fixed upper limit: for as long as the benefit outweighs the risks, with a review at least once a year. As the duration increases, the risk of breast cancer rises, especially with combined therapy, and after more than five years, according to the SmPC, an increased risk can persist for ten years or longer.¹,⁵ No reason to panic, but a good reason to ask yourself the question "Do I still need it?" honestly and regularly — with a symptom record rather than going on gut feeling.
Does your medication list fit with hormone therapy?
The interaction check shows whether lamotrigine, levothyroxine or St John's wort have a say.
As far as the risk of thrombosis is concerned, yes, according to current knowledge. Tablets pass through the liver first and increase the production of clotting factors there; estradiol given through the skin bypasses this route. In large observational studies, the risk of thrombosis was not increased with patches and gel. The form makes no difference to the risk of breast cancer.
On clean, dry, undamaged skin below the waist, for example the upper buttock area, the hip or the lower abdomen. The patch must not be stuck on or near the breasts. A different site is chosen at every change to avoid skin irritation.
If you still have a uterus, yes. Oestrogen on its own makes the lining of the womb grow and raises the risk of womb cancer. A progestogen on at least 12 to 14 days a month, or every day, balances out this risk. After a hysterectomy it is usually not needed.
According to the SmPC, you put on the new patch as soon as you notice and then go back to changing it on your usual days. A forgotten change can trigger spotting or breakthrough bleeding. If it happens more often, a fixed reminder for the change days helps.
If a longer period of immobilisation is to be expected after a planned operation, the SmPC recommends interrupting hormone therapy 4 to 6 weeks beforehand and only resuming it once you are fully mobile again. For minor procedures this is often not necessary. Discuss it early on with the practice carrying out the operation and with your gynaecologist.
Yes, that is possible as long as the gel or spray has not been fully absorbed. In children, this can lead to premature breast development. Wash your hands after applying it, let the area dry and cover it, and follow the instructions in the package leaflet on skin contact.
Summaries of Product Characteristics (SmPCs) for estradiol (transdermal patches, e.g. Fem7 50 µg/24 h, as of December 2025; estradiol tablets and gel; current version) — German source. fachinfo.de
S3 guideline on the peri- and postmenopause — diagnosis and interventions (DGGG, SGGG, OEGGG; AWMF reg. no. 015-062, 2020 version; update 3.0 as a consultation version, 2026) — German source. awmf.org
Canonico M et al.: Hormone therapy and venous thromboembolism among postmenopausal women: impact of the route of estrogen administration and progestogens — the ESTHER study. Circulation 2007;115:840–845. pubmed.ncbi.nlm.nih.gov
Vinogradova Y, Coupland C, Hippisley-Cox J: Use of hormone replacement therapy and risk of venous thromboembolism: nested case-control studies using the QResearch and CPRD databases. BMJ 2019;364:k4810. bmj.com
Collaborative Group on Hormonal Factors in Breast Cancer: Type and timing of menopausal hormone therapy and breast cancer risk — individual participant meta-analysis of the worldwide epidemiological evidence. Lancet 2019;394:1159–1168. thelancet.com
Gesundheitsinformation.de (IQWiG): Menopause — hormone therapy and other treatment options. Accessed 2026 — German source. gesundheitsinformation.de
Keep your hormone therapy under control — with brite
Patch changes, progestogen days, bleeding calendar and interaction check in one place. Free.
Medical disclaimer: This article is for general information and does not replace medical advice, diagnosis or treatment. Do not switch between tablet, patch and gel on your own, and do not leave out the progestogen if you have a uterus. If you have a painful swelling of one leg, sudden shortness of breath, chest pain, paralysis or a speech disturbance, call 112 (emergency number in Germany) immediately. New bleeding after a longer period of stable treatment should be checked by a doctor. The choice of dosage form and the dose are always set individually by the treating practice. Last updated: September 2026.
.gif)
