Hormone Replacement Therapy (HRT): Uses, Types, Dosage, Side Effects & Risks

At a Glance

What is Hormone Replacement Therapy (HRT)?

Hormone Replacement Therapy (HRT) is the use of estrogen, or a combination of estrogen and a progestogen, in women around or after menopause. It is mainly used to relieve symptoms such as hot flashes, night sweats and vaginal dryness. It is also used to prevent bone loss in selected postmenopausal women, and to treat estrogen deficiency in women whose ovaries stop working early. Common types include:

• Systemic estrogen therapy (tablets, patches, gels): treats symptoms throughout the body. Estrogen alone is generally used after hysterectomy.

• Estrogen plus progestogen therapy: for women who still have a uterus, because the progestogen protects the uterine lining.

• Local (vaginal) estrogen: creams, tablets or rings that mainly treat vaginal and urinary symptoms. They are not interchangeable with systemic therapy.

HRT should be prescribed and reviewed by a doctor, such as a gynecologist or endocrinologist.

How HRT Works

HRT replaces estrogen, the main hormone the ovaries stop producing after menopause. Estrogen acts on tissues such as the brain’s temperature-control centers, the vagina and the bones, which helps relieve hot flashes and vaginal symptoms and reduces bone loss. When systemic estrogen is given to a woman with a uterus, a progestogen is added because it reduces the risk of overgrowth of the uterine lining (endometrial hyperplasia), which can be a precursor to endometrial cancer. Different estrogens, doses and routes act differently in the body, so products are not interchangeable.

When HRT Is Used

• Menopausal symptoms: Systemic HRT can treat moderate to severe hot flashes and night sweats.

• Vaginal and vulvar symptoms: For moderate to severe dryness and discomfort due to menopause, low-dose local vaginal estrogen products are usually considered first when these are the only symptoms. Systemic HRT can also treat them.

• Osteoporosis prevention (selected women): Some products are approved to prevent postmenopausal bone loss. When this is the only reason, therapy is generally considered only for women at significant risk of osteoporosis and after non-estrogen medicines have been carefully considered. HRT is not the first-line treatment for everyone.

• Premature or early menopause, or ovarian insufficiency: Used to treat low estrogen (hypoestrogenism) in women whose ovaries stop working early, naturally or after surgery or other treatment. Specialists individualize the treatment.

Mood changes and irritability can accompany menopause, but they are not an approved indication for HRT. Discuss them with your doctor.

Dosage and How to Take It

There is no universal HRT dose. Doses depend on the product, route (oral, patch, gel or vaginal), the condition treated and your response, and a dose of one estrogen is not equal to the same number of milligrams of another. Oral, transdermal and vaginal doses cannot be directly converted. The examples below are product-specific and come from US prescribing information. They are general information only, and your doctor decides the product, dose and schedule.

• Oral estradiol tablets, for hot flashes and vaginal atrophy: the usual initial dose is 1 to 2 mg daily, adjusted as needed to control symptoms. For osteoporosis prevention, the label says the lowest effective dose has not been determined.

• Oral conjugated estrogens (Premarin tablets, from the April 2025 US label): treatment generally starts at 0.3 mg daily for hot flashes, vaginal symptoms or osteoporosis prevention, and is then adjusted according to response. It can be given continuously or in cycles (for example 25 days on and 5 days off).

• Estrogen plus progestogen: the progestogen schedule depends on the regimen. For example, the Provera (medroxyprogesterone acetate tablets) label lists 5 or 10 mg daily for 12 to 14 consecutive days per month, for postmenopausal women with a uterus who take oral conjugated estrogens 0.625 mg daily. Combined products, such as estradiol with dydrogesterone, follow their own product schedules.

• Early menopause or ovarian failure (Premarin-specific examples): the Premarin label lists 0.3 to 0.625 mg cyclically for female hypogonadism and 1.25 mg cyclically for castration or primary ovarian failure, adjusted to the patient. These are not universal doses, and a specialist decides the treatment.

• Vaginal and patch or gel products: these have their own product-specific doses. Follow your doctor’s prescription.

• Injectable medroxyprogesterone has other uses (for example contraception or cancer treatment) and is not a standard HRT regimen.

Dose and duration: Your doctor chooses an effective dose and length of treatment based on your symptoms, risk factors and goals, and reviews regularly whether you still need it (for example every 3 to 6 months). Some prescribing information (such as the April 2025 Premarin label) still advises the lowest effective dose for the shortest duration consistent with treatment goals. Labels are being updated, so follow your current product information and your doctor’s advice.

Take this medicine only as advised by your doctor or healthcare professional. Do not start, stop, or change the dose on your own.

Side Effects

Common side effects (they vary by product and route) include:

• Breast pain or tenderness

• Headache

• Nausea, bloating and abdominal cramps

• Irregular vaginal bleeding or spotting

• Fluid retention and vaginal yeast infections

Serious risks need prompt medical attention. The size of these risks is not identical for every product. It depends on age, time since menopause, route (for example oral vs transdermal), formulation, estrogen alone vs estrogen plus progestogen, duration, and your baseline cardiovascular and blood clot risk:

• Blood clots and stroke: Studies of oral estrogen alone found more stroke and deep vein thrombosis. Studies of oral estrogen plus progestin found more clots, pulmonary embolism, stroke and heart attack. The risk may differ between oral and transdermal forms, so your doctor considers the route.

• Breast cancer: In the Women’s Health Initiative study of oral conjugated estrogens with medroxyprogesterone, combined therapy was associated with a small increase in invasive breast cancer, while estrogen alone was not in that study. Risk depends on the type and duration of therapy.

• Endometrial cancer: Systemic estrogen without a progestogen increases the risk in women with a uterus.

• Dementia: In women aged 65 and older in the Women’s Health Initiative Memory Study, hormone therapy was associated with an increased risk of probable dementia. It is unknown whether this applies to younger postmenopausal women.

• Gallbladder disease, high blood pressure, raised triglycerides, retinal blood clots, and rarely severe allergic reactions

Seek immediate care for chest pain, sudden breathlessness, leg swelling or pain, sudden severe headache, vision or speech changes, or sudden vision loss. Report new breast lumps and any unusual vaginal bleeding promptly.

Precautions and Monitoring

• Contraindications are product-specific. According to the US oral conjugated estrogens (Premarin) label, systemic hormone therapy should generally not be used in people with undiagnosed abnormal vaginal bleeding, breast cancer or other estrogen-dependent cancers, active or past blood clots, active or past stroke or heart attack, liver disease, known clotting disorders (thrombophilia), or a past severe allergic reaction to the product. Other products, including local vaginal estrogens, have their own labels, and these cautions may apply differently, so your doctor decides.

• Tell your doctor about migraine, epilepsy, asthma, diabetes, lupus, endometriosis, thyroid, kidney or heart problems, and high triglycerides or calcium.

• Doctors usually advise regular breast examinations and mammograms based on age and risk, and prompt evaluation of any new vaginal bleeding.

• Surgery or long immobility: Tell your surgeon and doctor that you use HRT. Whether to pause it depends on the formulation and route, the type of surgery, your clot risk and other individual factors, and is decided by your treating doctor or perioperative team. Do not stop on your own.

• FDA labeling update (US, 2025–2026): In February 2026 the US FDA approved label changes for the first six menopausal hormone therapy products, with more products expected. The changes removed risk statements on cardiovascular disease, breast cancer and probable dementia from those products’ boxed warnings. The boxed warning for endometrial cancer remains for systemic estrogen-alone products. These changes apply to the products whose labels were updated, not to every HRT product worldwide. Labels differ by product and country, and the risk information can still appear in other parts of the labeling and in clinical guidance.

Drug Interactions

Interactions are product-specific. Different estrogens and progestogens are processed differently by the body, and routes such as patches and vaginal products can differ from tablets. Only your doctor or pharmacist can say which apply to your product. As examples, the US oral conjugated estrogens (Premarin) label states:

• Medicines that may lower estrogen levels (enzyme inducers): St. John’s Wort, phenobarbital, carbamazepine and rifampin may reduce estrogen levels, possibly reducing the effect or changing the bleeding pattern.

• Medicines that may raise estrogen levels (enzyme inhibitors): Erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice may increase estrogen levels and side effects.

• Thyroid hormone medicine: Estrogen can raise thyroid-binding protein levels, so women on thyroid replacement may need monitoring and dose adjustment.

Other HRT products may have different or additional interactions. Tell your doctor and pharmacist about all prescription medicines, over-the-counter medicines and supplements you take.

Pregnancy and Breastfeeding

HRT is not indicated for use during pregnancy. If you are or may be pregnant, speak to your doctor.

Estrogens and progestins, and their breakdown products, can pass into breast milk and may reduce milk production. The effect can vary by product, dose, route and timing, and it is less likely once breastfeeding is well established. Discuss breastfeeding with your doctor before using any hormone product.

Brands, Strengths and Approximate Price in India

HRT products marketed in India may include Progynova (estradiol valerate) and Femoston (estradiol with dydrogesterone). This is not an exhaustive list, and availability can change. Estrace is a US brand name, and I could not confirm that Premarin or Provera are currently marketed in India.

• Progynova (estradiol valerate tablets, estrogen only): listed in 1 mg and 2 mg strengths. Strengths and pack sizes differ by listing.

• Femoston 2/10 Combipack (estradiol with dydrogesterone, combined sequential therapy): a 28-tablet pack.

Approximate price in India (listing-based, one product only): a Truemeds listing updated January 2025 showed a printed MRP of ₹1,507 for Femoston 2/10 Combipack, 28 tablets. This applies only to that product, strength and pack, and may no longer be current. It is not the price of HRT in general.

HRT prices vary widely by formulation (tablets, patches, gels, vaginal products), brand, strength, pack size, pharmacy and location, so check the current price with your pharmacist.

How HealthPil Can Help

Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about this treatment, its side effects, or your treatment plan, you can consult a doctor through HealthPil, including gynecologists and endocrinologists for tailored treatment plans.