Evidence summary: which hormone treatment, for which outcome?
| Option | What the evidence shows | Evidence grade | Key safety notes |
|---|---|---|---|
| Oral 17β-estradiol — hot-flash frequency | The studied low-dose oral regimen reduced hot-flash frequency in a controlled trial. This does not establish the same result for every dose or hormone combination. 2023 Nonhormone Therapy Position Statement — includes the oral estradiol trial | B | Requires assessment of systemic estrogen risks and uterine-lining protection where needed. Estrogen therapy is not contraception. |
| Oral conjugated estrogens, as studied in Premarin — moderate-to-severe hot flashes | Controlled studies support symptom relief from this estrogen mixture. A different oral formulation cannot automatically inherit its grade. | A | Clot, cancer, liver and bleeding history matter. Breast tenderness, nausea and bleeding can occur; interactions need review. |
| Estradiol patch, as studied in Climara — moderate-to-severe hot flashes | Placebo-controlled trials support relief with the studied patch system. This is an efficacy grade, not a claim that patches remove all risk. | A | Systemic estrogen precautions still apply. Uterine protection may be needed; adhesion and skin irritation can affect use. |
| Estradiol gel, as studied in Divigel — hot flashes | The product-specific short-term trial supports relief, with limits in precision and replication. Different exposures and untested gels are not interchangeable. Divigel — FDA approval label documenting the gel trial (2007) | B | Follow the exact product's drying, contact and flammability precautions. Prevent transfer to other people, children and pets. Systemic estrogen risks remain. |
| Estradiol spray, as studied in Evamist — hot flashes | The studied spray reduced hot-flash frequency. Precision, early severity results and replication limit how broadly the findings can be applied. | B | Prevent accidental exposure through treated skin and follow fire or flame precautions until dry. Uterine protection and systemic estrogen assessment still matter. |
| Custom-compounded estrogen/progesterone cream — claimed safer or superior | The claimed safety superiority is not established. Evidence for an approved ingredient does not automatically validate a finished compounded mixture. | D | Variable potency, contamination and inadequate uterine protection are concerns. A progesterone-containing cream must not be assumed to provide adequate protection. |
| Oral conjugated equine estrogens + medroxyprogesterone acetate — primary coronary prevention | The WHI trial found an unfavourable balance for this prevention purpose in its studied population. Symptom relief is a separate treatment goal. | E | The trial found increased vascular harms. This specific regimen should not be chosen on a claim that it prevents coronary disease. |
| The WHIMS combined oral conjugated equine estrogens + medroxyprogesterone acetate regimen — dementia prevention when begun at age 65+ | WHIMS found increased probable dementia with this regimen in women aged 65 or older. It does not support this preventive use. WHIMS — combined oral hormones and dementia in women aged 65 or older (2003) | E | Do not transfer the precise result to every age or hormone route, or turn it into a claim that starting earlier prevents dementia. |
Important grading note: There is no single A–E grade for ‘HRT’. Each letter belongs to the specific formulation, route, population and outcome assessed in Menopause Decoded. A means strong and directly relevant; B supportive with meaningful limits; C uncertain, mixed or modest; D little reliable support; E no meaningful benefit, or an unfavourable proposition. These are Decoded Press editorial appraisals. A strong symptom-relief grade does not cancel a contraindication or establish long-term safety.
What benefits can hormone therapy provide?
The treatments above have evidence for hot-flash relief. The outcome you want to improve should guide the conversation.
Relief from hot flashes and night sweats can make daily life more manageable. But evidence for hot-flash relief does not establish a treatment for every symptom that appears in midlife.
If one symptom improves and another does not, both deserve attention at the review. Persistent fatigue, sleep problems or cognitive concerns should not automatically lead to more estrogen.
Low-dose vaginal estrogen for local vaginal or urinary symptoms is a different treatment decision from systemic estrogen for hot flashes. The ingredient, route and intended job all matter.
Are patches and gels safer than estrogen tablets?
Route matters, but skin delivery does not mean risk-free.
Oral estrogen passes through the gut and liver before reaching the wider circulation. Transdermal estrogen enters through the skin.
Evidence suggesting lower clot risk with skin-delivered estrogen is largely observational. It helps inform clinical choices, but is not a large randomised head-to-head safety trial of every patch, gel and spray. Other risks still require assessment.
Practical differences matter too: patch adhesion, skin irritation, drying time, transfer precautions, cost and availability. The number on one product is not a conversion chart for another.
Why might I need progesterone or another progestogen?
An intact uterus usually needs protection when systemic estrogen is used.
Systemic estrogen can stimulate growth of the uterine lining. An appropriate progestogen regimen helps control that growth, and must be matched to the estrogen exposure and the person's circumstances.
Feeling better does not tell you whether the lining is protected. Do not reduce or replace the protective component yourself because it causes unwanted effects; ask the prescriber to review the whole plan.
If your uterus has been removed, the decision may differ. Your clinician should confirm the operation and relevant history. A retail progesterone cream is not an established substitute for prescribed uterine-lining protection.
What are the main risks to discuss?
Ask about clot, stroke, breast cancer, uterine-lining and bleeding risks for the exact treatment being proposed.
The WHI combined-therapy trial found real harms with oral conjugated equine estrogens plus medroxyprogesterone acetate. Its long-term breast cancer findings differed from those of the separate estrogen-only trial in people with a prior hysterectomy. Different regimens and trial populations must stay distinct.
The result for one progestogen cannot be assigned unchanged to every other progestogen. Equally, a different preparation does not make uncertainty disappear.
Age and time since menopause help frame the discussion. Starting treatment much later is a different question from starting near menopause, and continuing a helpful treatment is different from starting it. None of these distinctions guarantees zero risk.
Ask for absolute risk as well as relative risk, over the same period and with the same denominator. A study average cannot calculate your personal risk by itself.
Safety: when does hormone therapy need particular caution?
Unexplained bleeding, hormone-sensitive cancer, past clots or stroke, and liver disease need clinical assessment and can rule out systemic treatment.
Bring your medical history, current medicines and supplements to the appointment. A prescriber and pharmacist should check current information for the exact product dispensed, including interactions and monitoring.
Sudden chest pain, breathlessness, one-sided weakness or trouble speaking needs urgent medical care. New or unexplained vaginal bleeding also needs assessment; do not assume a medicine explains it and leave it unchecked.
Estrogen therapy is not contraception. If pregnancy is possible, ask separately about contraception. For gels and sprays, follow the current product's precautions against transfer to others and fire or flame exposure.
Are custom-compounded ‘bioidentical’ hormones safer?
The label ‘bioidentical’ does not establish that a custom-compounded product is safer or superior.
Some regulated medicines contain hormones chemically identical to those the body makes. Molecular structure and how a finished medicine is regulated are separate facts.
Compounding can meet a genuine need when an approved product is unsuitable. That role does not establish superiority for routine use. The book's D applies specifically to the claimed superior safety of compounded estrogen/progesterone cream, rather than to every hormone described as bioidentical.
Should I take hormone therapy to prevent heart disease or dementia?
Symptom relief and disease prevention are separate claims, requiring separate evidence.
The book gives E to the WHI combined oral regimen for primary coronary prevention, and E to the WHIMS combined oral regimen for dementia prevention when begun at age 65 or older.
Those E grades do not grade hormone therapy as a whole. They also do not prove that starting a different regimen earlier prevents dementia. Treatment for symptoms needs its own discussion of benefits, risks and priorities.
Related questions
What to ask at your appointment
- Which symptom are we treating, and what improvement should I realistically expect?
- Which exact hormone, product, route and combination are you proposing, and why?
- How do my age, time since menopause and medical history affect this decision?
- If I have a uterus, how will its lining be protected?
- What are my likely benefits and harms in absolute terms, over the same period?
- Which findings come from randomised trials, and which are observational?
- Could my medicines or supplements interact with the treatment?
- What monitoring do I need, and when will we review whether it is helping?
- Which symptoms need urgent care or a prompt review?
- What should I do if I have side effects or my usual product is unavailable?
Frequently asked questions
Is HRT good or bad for menopause?
Hormone therapy can provide substantial symptom relief, but there is no single benefit-risk answer for everyone. The exact formulation, route, combination, treatment goal and medical history matter. Menopause Decoded grades specific claims, rather than giving HRT one blanket grade.
Does an A grade mean a hormone treatment is safe for everyone?
No. An A grade describes strong, directly relevant evidence for the specific outcome assessed. It does not cancel contraindications, interactions, monitoring requirements or the need to consider personal risk.
Do estrogen patches remove the risk of blood clots?
Skin delivery does not remove all risk. Evidence suggesting lower clot risk than oral estrogen is largely observational. Your clinician still needs to assess the exact treatment and your medical history.
Do I need progesterone if I have a uterus?
With systemic estrogen, an intact uterus usually needs an appropriate uterine-lining protection regimen. The exact drug and plan must fit the estrogen exposure. Do not assume a retail progesterone cream provides adequate protection.
Are all bioidentical hormones custom-compounded?
No. Some regulated medicines contain hormones chemically identical to those made by the body. Custom compounding is a separate issue, and the word bioidentical does not establish superior safety.
Does hormone therapy prevent dementia?
The studied WHIMS combined oral regimen increased probable dementia when begun in women aged 65 or older. This finding does not establish the effects of every age, route or formulation, and does not prove that starting earlier prevents dementia.
Can HRT be used as contraception?
Estrogen therapy is not contraception. If pregnancy is possible, ask your clinician about a separate contraception plan suited to your circumstances.
Sources
Adapted from Menopause Decoded, First Edition (2026), chapters 16, 17, 21, 32 and 40. Evidence grades follow the final ISBN'd book. Its targeted source checks extend through 18 September 2026; the guide's review date records this adaptation, not a new systematic review. Product names identify what was studied, not an endorsement or a claim of Australian availability. Historical approval labels document trials; current Australian product information, availability and suitability must be checked with a prescriber or pharmacist.
- 2022 Hormone Therapy Position Statement
- 2023 Nonhormone Therapy Position Statement — includes the oral estradiol trial
- Premarin — prescribing information and clinical studies
- Climara — FDA label documenting the patch trials (2017)
- Divigel — FDA approval label documenting the gel trial (2007)
- Evamist — prescribing information and trial results
- British Menopause Society — progestogens and endometrial protection
- FDA — menopause medicines and hormone claims
- WHI — combined oral hormone therapy primary report (2002)
- WHI — long-term breast cancer follow-up (2020)
- WHI — age and timing analysis (2007)
- WHIMS — combined oral hormones and dementia in women aged 65 or older (2003)
This guide provides general education, not an individual treatment plan. Do not start, stop, swap or change prescribed hormone treatment on the basis of this guide. Discuss your exact treatment with a qualified healthcare professional who knows your history. Read the full Medical Disclaimer.