Hormone replacement therapy is one of the most effective treatments for menopause symptoms in the UK -- but starting HRT without a clear picture of your baseline health is like adjusting a thermostat without knowing the current temperature. The right blood tests before and during HRT give your prescriber the data they need to choose the correct type, set an appropriate dose, and monitor your response safely over time.
Whether you are considering HRT for the first time, have been told by your GP that "your bloods are fine" without much detail, or want to understand what a pre-HRT blood panel should actually include, this guide covers everything: which tests matter, why each one is relevant to HRT decisions, the types of HRT available in the UK, how blood tests guide dose adjustments, and when to retest once you have started treatment.
Key Takeaways
- A pre-HRT blood test should cover more than hormones. A comprehensive baseline includes reproductive hormones, thyroid function, liver enzymes, lipid profile, metabolic markers, and key nutrients -- not just FSH and oestradiol.
- Blood tests help your prescriber choose the right HRT type and dose. Baseline oestradiol, testosterone, SHBG, and thyroid values directly influence whether you are prescribed oestrogen-only or combined HRT, transdermal or oral preparations, and whether testosterone should be considered.
- Liver function and lipids should be checked before starting. Oral oestrogen passes through the liver and can affect cholesterol and triglycerides. Transdermal oestrogen (patches, gels, sprays) bypasses the liver and is safer for women with elevated lipids or liver concerns.
- The British Menopause Society (BMS) recommends oestradiol testing to check absorption in women with persistent symptoms on transdermal HRT -- but emphasises that symptom response, not blood levels alone, should guide treatment.
- Retest at 3 months, 6 months, and annually to monitor oestradiol absorption, thyroid interaction, metabolic health, and -- if prescribed -- testosterone levels within the female range.
Why Blood Tests Matter Before Starting HRT
The NICE guideline NG23 states that menopause in women aged 45 and over should be diagnosed clinically -- based on symptoms -- without the need for blood tests. This is important context: you do not need a blood test to be prescribed HRT.
However, blood tests before HRT serve a different and equally important purpose: they establish a baseline that your prescriber can use to make more informed decisions about your treatment. Pre-HRT blood work helps in three specific ways:
- Ruling out conditions that mimic menopause. Fatigue, brain fog, weight gain, low mood, and hair thinning overlap with hypothyroidism, iron deficiency, and vitamin D deficiency. Treating the wrong condition -- or starting HRT when a thyroid issue is the primary driver -- wastes time and delays relief.
- Guiding HRT type selection. Your liver function, lipid profile, and cardiovascular risk factors influence whether transdermal or oral oestrogen is safer. Your testosterone and SHBG levels determine whether testosterone therapy should be part of the conversation.
- Creating a reference point for monitoring. Once you are on HRT, the only way to assess how your body has responded is to compare follow-up results against your baseline. Without a pre-treatment snapshot, your prescriber is interpreting numbers in isolation.
The Complete Pre-HRT Blood Test Panel
A thorough pre-HRT assessment should cover five categories: reproductive hormones, thyroid function, liver health, cardiovascular and metabolic markers, and key nutrients. Here is what to test and why each biomarker matters for HRT decisions specifically.
Reproductive Hormones
| Biomarker | What It Tells You | HRT Relevance |
|---|---|---|
| FSH | Follicle-stimulating hormone rises as ovarian function declines. The pituitary produces more FSH to try to stimulate follicle development. | Elevated FSH (above 25-30 IU/L) supports the clinical picture of menopause, particularly in women under 45 or those with premature ovarian insufficiency. Not useful for monitoring once HRT is started, as exogenous oestrogen suppresses FSH. |
| LH | Luteinising hormone rises alongside FSH when the ovaries become less responsive. | Elevated LH alongside elevated FSH strengthens the hormonal evidence of ovarian decline. Assessed together with FSH, not in isolation. |
| Oestradiol (E2) | The primary oestrogen produced by the ovaries. Drives bone density, cardiovascular protection, brain function, and skin integrity. | Baseline oestradiol documents your pre-treatment level. Post-menopausal oestradiol is typically below 100 pmol/L. On HRT, this marker is used to check absorption of transdermal preparations (patches, gels, sprays). The BMS 2025 guidance notes that serum oestradiol can help assess absorption when symptoms persist despite treatment. |
| Progesterone | Produced after ovulation to prepare the uterine lining. A marker of whether ovulation is still occurring. | Low progesterone (below 5 nmol/L mid-luteal phase) indicates anovulatory cycles, common in perimenopause. This informs the decision about whether you need combined HRT (oestrogen plus progestogen) or oestrogen-only, and whether sequential or continuous dosing is appropriate. |
| Testosterone | Supports libido, energy, muscle mass, bone density, and cognitive function in women. Declines gradually with age. | The BMS recommends measuring total testosterone and SHBG before considering testosterone therapy. Baseline levels determine whether low testosterone is contributing to symptoms like reduced libido, fatigue, and brain fog that persist even after oestrogen replacement. Testosterone must be monitored within the female physiological range if prescribed. |
| SHBG | Sex hormone-binding globulin binds sex hormones, reducing their bioavailability. Only unbound hormones are active at tissue level. | SHBG often rises after menopause and rises further with oral HRT (a first-pass liver effect). High SHBG can mean that even if total hormone levels look adequate on paper, the amount available to your tissues is low. This is one reason transdermal oestrogen is preferred -- it does not raise SHBG to the same extent as oral preparations. |
Thyroid Function
Thyroid disorders are significantly more common in women, and the risk increases around the menopausal transition. The symptom overlap between menopause and thyroid dysfunction is so extensive -- fatigue, weight gain, brain fog, low mood, hair thinning, heart palpitations -- that misdiagnosis is common. Testing thyroid function before starting HRT is essential because:
- An undiagnosed underactive thyroid will not improve with HRT. If thyroid dysfunction is driving your symptoms, treating the thyroid may resolve them without HRT, or in addition to it.
- Oral oestrogen increases thyroxine-binding globulin (TBG), which can affect thyroid hormone availability. Women who are already on levothyroxine for hypothyroidism and then start oral HRT may need their thyroid dose adjusted upward. Transdermal oestrogen does not have this effect.
| Biomarker | What It Tells You | HRT Relevance |
|---|---|---|
| TSH | Thyroid-stimulating hormone. The primary screening marker for thyroid function. | Elevated TSH indicates hypothyroidism. Baseline TSH is critical for comparison if you later start oral HRT, which can alter thyroid hormone binding. |
| Free T4 | The main thyroid hormone circulating in the blood, converted to the active form (T3) in tissues. | Low Free T4 with elevated TSH confirms hypothyroidism. Baseline values are important for women who may later need thyroid dose adjustments when starting oral oestrogen. |
Liver Function
Liver health is directly relevant to HRT decisions because oral oestrogen undergoes first-pass metabolism through the liver. This means oral HRT can increase the production of clotting factors, raise triglycerides, increase SHBG, and affect cholesterol balance. Women with pre-existing liver concerns are typically directed toward transdermal oestrogen, which bypasses the liver entirely.
| Biomarker | What It Tells You | HRT Relevance |
|---|---|---|
| ALT | Alanine aminotransferase. The most specific marker of liver cell damage. | Elevated ALT before starting HRT warrants investigation. Oral oestrogen is metabolised by the liver, so pre-existing liver disease may make transdermal preparations the safer choice. Baseline values allow comparison during monitoring. |
| GGT | Gamma-glutamyl transferase. Sensitive to liver and bile duct disease, also elevated by alcohol use. | Provides additional liver context alongside ALT. Elevated GGT in combination with raised ALT strengthens the case for transdermal over oral HRT. |
Lipid Profile and Metabolic Markers
Cardiovascular risk increases after menopause as oestrogen's protective effects on blood vessel function and lipid metabolism diminish. A baseline lipid and metabolic panel before HRT serves two purposes: it identifies pre-existing risk factors that influence HRT route selection, and it creates a reference for monitoring cardiovascular health during treatment.
| Biomarker | What It Tells You | HRT Relevance |
|---|---|---|
| Total Cholesterol, HDL, LDL | Full lipid breakdown assessing cardiovascular risk. | Oral oestrogen can raise HDL (beneficial) but also raise triglycerides (unfavourable). Transdermal oestrogen has a neutral effect on triglycerides. Elevated baseline triglycerides favour transdermal route. HRT timing within 10 years of menopause is associated with cardiovascular benefit. |
| HbA1c | Measures 3-month average blood glucose. Screens for pre-diabetes and type 2 diabetes. | Menopause increases insulin resistance due to declining oestrogen. HRT may improve insulin sensitivity in some women. Baseline HbA1c documents metabolic status before treatment and provides a comparison point for follow-up. |
| CRP | C-reactive protein. A marker of systemic inflammation. | Oral oestrogen can raise CRP (an inflammatory marker) due to its first-pass liver effect, while transdermal oestrogen does not. A raised baseline CRP adds to the case for transdermal preparations and provides a cardiovascular risk indicator. |
Key Nutrients
| Biomarker | What It Tells You | HRT Relevance |
|---|---|---|
| Vitamin D | Essential for bone health, immune function, and mood regulation. | Declining oestrogen accelerates bone density loss. Adequate vitamin D (above 75 nmol/L) is critical for calcium absorption and reducing osteoporosis risk. Low vitamin D is also responsible for fatigue, muscle pain, and low mood that may be wrongly attributed to menopause. |
| Ferritin | The body's iron storage protein. The most sensitive marker of iron status. | Heavy or irregular periods during perimenopause can deplete iron stores. Low ferritin (below 30 mcg/L) causes exhaustion, breathlessness, and hair loss. Correcting iron deficiency before starting HRT ensures that persistent fatigue on treatment is not misattributed to an inadequate HRT dose. |
Get Your Pre-HRT Baseline Panel at Home
The Female Hormones Clarity 31 blood test covers reproductive hormones (FSH, LH, oestradiol, progesterone, testosterone, SHBG), thyroid function, liver health, iron, vitamin D, inflammation, and metabolic markers -- everything your prescriber needs to make informed HRT decisions. A professional phlebotomist visits your home for a venous blood draw. Results in 2-5 working days.
View Female Hormones Clarity 31 →No GP referral needed. Phlebotomist visit included.
Types of HRT Available in the UK
Understanding the different types of HRT helps explain why blood test results matter for treatment decisions. Your prescriber considers your symptoms, medical history, and blood work to choose the most appropriate regimen.
Oestrogen-Only HRT
Oestrogen-only HRT is prescribed for women who have had a hysterectomy (removal of the womb). Without a uterus, there is no risk of endometrial overgrowth from unopposed oestrogen, so progestogen is not needed. The optimal oestrogen used in modern HRT is 17-beta oestradiol -- a body identical hormone with the same molecular structure as the oestrogen your ovaries produce naturally.
Available forms in the UK include:
- Transdermal patches (e.g. Evorel, Estradot) -- applied to the skin once or twice weekly
- Transdermal gels (e.g. Oestrogel, Sandrena) -- applied daily to the skin
- Transdermal spray (Lenzetto) -- sprayed on the forearm daily
- Oral tablets (e.g. Elleste Solo, Zumenon) -- taken daily by mouth
Transdermal oestrogen (patches, gels, sprays) is generally recommended as the first-line choice because it is absorbed directly through the skin, bypasses the liver, and carries a lower risk of blood clots and stroke compared to oral preparations. The British Menopause Society and NICE both support transdermal oestrogen as the preferred route, particularly for women with cardiovascular risk factors, a BMI above 30, migraines with aura, or a personal or family history of blood clots.
Combined HRT (Oestrogen + Progestogen)
Women who still have a uterus need progestogen alongside oestrogen to protect the endometrium (womb lining) from abnormal thickening. The two main patterns are:
- Sequential (cyclical) combined HRT -- oestrogen taken continuously, with progestogen added for 10 to 14 days each month. This produces a regular monthly bleed and is typically prescribed for women in perimenopause who are still having some periods.
- Continuous combined HRT -- oestrogen and progestogen taken every day without a break. This is typically prescribed for women who have been postmenopausal for at least 12 months (no periods for a full year), as it aims to produce no bleeding at all.
The body identical progestogen available in the UK is micronised progesterone, branded as Utrogestan. It has the same molecular structure as the progesterone your body produces naturally and is generally associated with fewer side effects than older synthetic progestogens. Your prescriber may recommend Utrogestan taken orally (200mg for 12-14 days per month in sequential regimens, or 100mg daily for continuous regimens) or used vaginally.
Alternatively, the Mirena intrauterine system (IUS) provides progestogen directly to the uterus and can be used as the progestogen component of HRT, which is particularly convenient for women who also need contraception during perimenopause.
Testosterone for Women
Testosterone is not currently licensed for women in the UK, but it can be prescribed off-licence by GPs or specialists -- and this is supported by the British Menopause Society for women with reduced sexual desire that has not responded to oestrogen-based HRT alone.
Testosterone for women is typically given as a cream or gel at approximately one-tenth of the male dose. The BMS recommends that total testosterone and SHBG should be measured before starting testosterone therapy to ensure baseline levels are not already at or above the upper end of the female reference range. Blood tests are then needed at approximately 2 months after starting (or after any dose change) and at least annually once stable to ensure levels remain within the female physiological range.
How Your Blood Tests Influence HRT Type Selection
| Blood Test Finding | HRT Implication |
|---|---|
| Elevated triglycerides | Transdermal oestrogen preferred over oral. Oral oestrogen can raise triglycerides further. |
| Elevated ALT / abnormal liver function | Transdermal oestrogen preferred. Bypasses first-pass liver metabolism entirely. |
| High SHBG | Transdermal oestrogen preferred. Oral oestrogen raises SHBG further, reducing the bioavailability of oestradiol and testosterone. |
| Elevated CRP | Transdermal oestrogen preferred. Oral oestrogen can increase CRP; transdermal does not. |
| Low testosterone with persistent low libido / fatigue | Testosterone therapy may be considered alongside oestrogen-based HRT, per BMS guidance. |
| Abnormal TSH / thyroid dysfunction | Treat thyroid condition first or in parallel. If already on levothyroxine and starting oral HRT, thyroid dose may need increasing. |
| Low ferritin or vitamin D | Correct deficiencies before or alongside starting HRT. Persistent fatigue on HRT may be nutritional, not hormonal. |
| Elevated HbA1c (pre-diabetes range) | HRT may improve insulin sensitivity. Monitor HbA1c during treatment to assess metabolic response. |
How Blood Tests Guide HRT Dose Adjustments
Once you have started HRT, blood tests shift from baseline assessment to monitoring. The primary question becomes: is your current dose achieving adequate hormone levels, and is the treatment safe for your liver, lipids, and metabolic health?
Monitoring Oestradiol on HRT
The BMS 2025 Tool for Clinicians on serum oestradiol measurement clarifies the role and limitations of oestradiol blood tests during HRT:
- Routine oestradiol monitoring is not necessary for women who are doing well on HRT. If your symptoms have resolved and you feel well, there is no need for regular oestradiol blood tests.
- Oestradiol testing is useful when symptoms persist despite transdermal HRT. In this scenario, checking serum oestradiol can help assess whether you are absorbing enough oestrogen through the skin.
- There is no single target oestradiol level on HRT. The BMS emphasises that response to HRT should be based on symptom control, not on achieving a specific blood number. However, physiological oestradiol levels in premenopausal women generally range from approximately 110 to 1,300 pmol/L, and some clinicians aim for levels of 200-600 pmol/L on transdermal HRT as a rough guide.
- Individual absorption varies significantly. Two women on the same patch or gel dose may achieve very different serum oestradiol levels. This is one reason why blood testing can be clinically useful when symptoms are not improving.
Patches vs Gels: Absorption Differences
Research comparing oestradiol absorption across delivery methods shows distinct pharmacokinetic profiles:
- Oestradiol gels produce a peak concentration approximately 4-5 hours after application, with levels gradually declining until the next application. The fluctuation between peak and trough is approximately 56-67%.
- Oestradiol patches produce relatively stable levels during the middle of the wearing period, but lower levels at the start (as absorption ramps up) and toward the end (as the patch reservoir depletes). Overall fluctuation can be up to 89%.
Timing matters for testing. If you are on transdermal gel, testing approximately 4-6 hours after application captures near-peak levels. If you are on a twice-weekly patch, testing on day 2-3 of the patch (during the stable middle phase) gives the most representative reading. Discuss timing with your prescriber to ensure results are interpreted correctly.
Important: Oestradiol blood tests are less reliable for women taking oral HRT. First-pass liver metabolism means that blood levels do not accurately reflect tissue exposure. For oral preparations, symptoms remain the primary guide to dose adequacy.
Monitoring Testosterone
If you are prescribed testosterone as part of your HRT regimen, the BMS recommends the following monitoring schedule:
- Baseline: Total testosterone and SHBG before starting, to confirm levels are not already at or above the upper female range.
- 2 months after starting or any dose change: Recheck testosterone and SHBG to confirm levels remain within the female physiological range.
- Annually once stable: Ongoing monitoring to ensure levels remain appropriate and to watch for androgen excess symptoms (acne, hair growth, voice deepening).
Other Markers to Monitor on HRT
- TSH and Free T4: Particularly important if you are on both oral HRT and levothyroxine. Oral oestrogen increases thyroxine-binding globulin, which can reduce free thyroid hormone availability and may require a thyroid dose adjustment.
- Lipid profile: Check at 6-12 months to assess how HRT is affecting your cholesterol and triglycerides, especially if you are on oral oestrogen.
- HbA1c: If your baseline was in the pre-diabetes range, monitoring at 6-12 months can show whether HRT is having a positive effect on insulin sensitivity.
- Vitamin D: Annual testing is advisable given the increased osteoporosis risk post-menopause. Target levels above 75 nmol/L.
- Ferritin: Once periods have stopped (on continuous combined HRT or post-hysterectomy), ferritin levels often normalise. If they remain low, investigate other causes of iron loss.
When to Retest on HRT: The Monitoring Schedule
There is no single guideline that specifies exact retesting intervals for all HRT blood tests. However, combining BMS recommendations with clinical best practice, a reasonable monitoring schedule looks like this:
| Timepoint | What to Check | Purpose |
|---|---|---|
| Before starting HRT | Full panel: reproductive hormones, thyroid, liver, lipids, HbA1c, CRP, vitamin D, ferritin | Baseline assessment. Guides HRT type and route selection. |
| 3 months | Oestradiol (if symptoms persist), testosterone and SHBG (if testosterone prescribed), TSH (if on levothyroxine + oral HRT) | Early absorption check. Assess whether dose is adequate. Adjust testosterone or thyroid dose if needed. |
| 6 months | Oestradiol, testosterone/SHBG, lipid profile, liver function, HbA1c | Broader metabolic review. Check how HRT is affecting cardiovascular and liver markers compared to baseline. |
| Annually | Comprehensive panel (similar to baseline): hormones, thyroid, liver, lipids, HbA1c, vitamin D, ferritin | Full health review. Particularly important as cardiovascular and metabolic risk increase with age post-menopause. |
| After any dose change | Relevant marker (e.g. oestradiol after oestrogen dose change, testosterone after testosterone dose change) | Confirm the adjustment has achieved the intended effect. Typically 6-8 weeks after the change. |
If you are doing well on HRT -- symptoms resolved, no side effects -- some of these checks become less frequent. The 3-month review is primarily for women who are not yet feeling the benefit of treatment or who have started testosterone. The annual comprehensive panel, however, is advisable for all women on long-term HRT as part of general health surveillance.
What the BMS and NICE Say About HRT Blood Testing
It is worth summarising the official positions, because there is often confusion about what is "required" versus what is "recommended" versus what is clinically useful:
- NICE NG23: Menopause in women over 45 should be diagnosed clinically. Blood tests (FSH) are recommended for women aged 40-45 with symptoms, and are essential for diagnosing premature ovarian insufficiency in women under 40. NICE does not specify routine blood monitoring during HRT.
- BMS (2025): Routine oestrogen level monitoring is not necessary for women who are well on HRT. However, serum oestradiol measurement can be useful when symptoms persist despite treatment, particularly with transdermal preparations. The BMS emphasises that there is no recommended systemic oestrogen level on HRT -- treatment should be guided by symptoms. For testosterone, baseline and ongoing monitoring of total testosterone and SHBG is explicitly recommended.
- Clinical practice: Many menopause specialists and private prescribers request a broader baseline panel (including thyroid, liver, lipids, and metabolic markers) because this data directly informs the choice of HRT type and route. This is good clinical practice even if not explicitly mandated by guidelines.
Monitor Your HRT with Confidence
Whether you need a pre-HRT baseline or a follow-up panel to check absorption and metabolic health, the Female Hormones Clarity 31 test covers 31 biomarkers including oestradiol, testosterone, SHBG, thyroid, liver function, lipids, vitamin D, and ferritin. A certified phlebotomist visits your home -- no clinic appointment needed.
View Female Hormones Clarity 31 →Results reviewed by a doctor. Delivered within 2-5 working days.
For the most comprehensive assessment -- including advanced cardiovascular markers, detailed metabolic health, and additional micronutrients -- the Peak Insights 70 blood test covers 70 biomarkers in a single at-home appointment. This is particularly suited to annual health reviews for women on long-term HRT.
Timing Your Pre-HRT Blood Test
If you are still having periods (even irregular ones), timing your blood draw can improve the accuracy and interpretability of certain markers:
- FSH, LH, oestradiol: Best tested on day 2 to 5 of your menstrual cycle (early follicular phase), when baseline levels are most stable.
- Progesterone: Best tested on day 21 of a 28-day cycle (or 7 days after suspected ovulation). Below 5 nmol/L suggests anovulation.
- Testosterone, SHBG, thyroid, liver, lipids, vitamin D, ferritin: Can be tested at any point in your cycle.
If your periods have stopped entirely, you can test at any time. For the most consistent results, a morning fasting sample (before 10am, water only) is recommended, particularly for lipids, iron markers, and thyroid function.
If you are already on HRT and testing oestradiol levels, timing relative to your medication matters. For transdermal gel, test 4-6 hours after application. For patches, test on day 2-3 of a twice-weekly patch. For oral HRT, oestradiol blood levels are less meaningful due to first-pass metabolism -- symptoms guide dosing.
Establish Your Baseline Before Starting HRT
Before starting hormone replacement therapy, a baseline blood test covering oestradiol, FSH, testosterone, SHBG, thyroid function, liver markers, and lipids gives your prescriber the data they need to choose the right formulation and dose. It also creates a reference point for monitoring how well treatment is working once you start.
All results reviewed by a doctor. Free delivery. Results in 2-3 working days.
Frequently Asked Questions
Do I need a blood test before starting HRT?
Strictly speaking, no -- NICE guidelines state that menopause can be diagnosed clinically in women over 45, and HRT can be prescribed on that basis. However, a pre-HRT blood panel is strongly recommended by many clinicians because it establishes a baseline for monitoring, rules out thyroid dysfunction and nutritional deficiencies that mimic menopause, and provides data that influences the choice of HRT type and delivery route. It is especially important if you are under 45, have a family history of cardiovascular disease or blood clots, or are considering testosterone therapy.
Which blood tests should I ask for before HRT?
A comprehensive pre-HRT panel should include: FSH, LH, oestradiol, progesterone, testosterone, SHBG, TSH, Free T4, ALT (liver function), lipid profile (cholesterol, HDL, LDL, triglycerides), HbA1c, CRP, vitamin D, and ferritin. The Female Hormones Clarity 31 test covers all of these in a single panel.
Can I get HRT blood tests on the NHS?
Your GP may offer FSH testing if you are under 45, and may check basic liver function and lipids as part of a cardiovascular risk assessment. However, the full comprehensive panel described above is rarely available through a single NHS test request. Many women turn to private at-home blood tests to get the complete picture without multiple GP appointments and referrals.
How often should I have blood tests while on HRT?
If you are doing well on HRT and symptoms are controlled, routine blood tests are not strictly required. However, a reasonable monitoring schedule includes a check at 3 months (especially if symptoms persist or testosterone has been started), 6 months (broader metabolic review), and annually (comprehensive health check). Blood tests are also recommended 6-8 weeks after any dose change. Women on testosterone therapy should have testosterone and SHBG checked at baseline, 2 months after starting, and at least annually.
What oestradiol level should I aim for on HRT?
The British Menopause Society states that there is no recommended target oestradiol level on HRT. Treatment should be guided by symptom control, not a specific blood number. That said, premenopausal physiological oestradiol generally ranges from 110 to 1,300 pmol/L, and some clinicians use 200-600 pmol/L as a rough guide for transdermal HRT. If your symptoms persist despite adequate doses, checking oestradiol can reveal poor absorption. Remember that oestradiol blood levels are less reliable for oral HRT due to first-pass liver metabolism.
Does HRT affect thyroid medication?
Oral oestrogen (HRT taken by mouth) increases thyroxine-binding globulin (TBG), which binds more thyroid hormone and can reduce the amount of free thyroid hormone available to your tissues. Women on levothyroxine for hypothyroidism who start oral HRT may need their thyroid dose increased. Transdermal oestrogen (patches, gels, sprays) does not have this effect, making it the preferred option for women with thyroid conditions. If you are on both oral HRT and thyroid medication, have your TSH and Free T4 rechecked 6-8 weeks after starting or changing your HRT.
Is transdermal HRT safer than tablets?
Transdermal oestrogen (patches, gels, sprays) is generally considered safer than oral tablets for most women. It does not increase the risk of blood clots (VTE) at standard doses, does not raise triglycerides, does not increase CRP, does not raise SHBG to the same extent, and does not affect thyroxine-binding globulin. This is because transdermal delivery bypasses the liver's first-pass metabolism. NICE and the BMS both recommend transdermal oestrogen as the preferred route, particularly for women with obesity, cardiovascular risk factors, migraines with aura, or a history of blood clots.
Can I test HRT blood levels at home?
Yes. At-home blood tests with a professional phlebotomist visit are available in the UK and provide laboratory-quality venous blood samples -- the same type used by NHS laboratories. This is more accurate than finger-prick testing for hormone measurements, particularly at the low concentrations relevant to menopausal and HRT-treated women. Results are typically available within 2-5 working days and can be shared with your GP or menopause specialist to inform treatment decisions.
Important: This article is for educational purposes only and does not constitute medical advice. Lola Health provides blood testing services -- we do not prescribe medications including HRT. Any decisions about starting, changing, or stopping HRT should be made in consultation with your GP, menopause specialist, or another qualified healthcare professional who can assess your full medical history, symptoms, and individual risk factors.
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