Hormone Therapy for Women: What It Treats, When to Start, and What the New Science Says

By Rachael Schultz

For years, hormone replacement therapy (HRT) has carried one of the FDA’s most severe caution labels: the black box warning. That small black rectangle on the package insert signaled an elevated risk of breast cancer, heart disease, and stroke — and made millions of women think twice about using hormones to manage the often-brutal symptoms of perimenopause and postmenopause.

But as of late 2025, that warning is officially gone.

In November, the FDA quietly removed the black box warning from estrogen, estrogen-progesterone, and other common hormone therapies used to treat menopause, signaling a major shift in how the safety of HRT is understood. While some warnings remain for older women and certain forms of HRT, experts say this is a long-overdue clarification — and an important green light for younger women to get the support they need.

Practitioners have known for a long time that hormone therapy is highly effective at relieving menopausal symptoms and reducing their risk for certain diseases, says Gloria A Bachmann, MD, professor of obstetrics and gynecology and medicine and co-director of the Women’s Health Institute at Rutgers University.

Now, a new study presented at the 2025 Annual Meeting of The Menopause Society reinforces the idea that starting hormone therapy earlier is not only safer, but may also protect against chronic disease rather than increase your risk of it.

Here’s everything you need to know about the updated guidance on hormone replacement therapy.

What is hormone replacement therapy?

Hormone therapy is an umbrella term for medications that supplement your body’s natural hormones. Contraception (birth control) falls into this category, typically delivering progesterone or a combination of progesterone and estrogen to regulate your menstrual cycle.

Hormone replacement therapy (HRT) is a specific type of hormone therapy used to treat menopause symptoms. It’s usually estrogen-based, but may also include progesterone, and in some cases testosterone.

The reason you may need HRT: When you ovulate, your ovaries release a flood of hormones, namely estrogen and progesterone. These hormones regulate dozens of systems in your body, including metabolism, blood flow to the brain, heart efficiency and health, and even your nervous system. 

As ovulation becomes irregular and you enter menopause, your ovaries are no longer producing these crucial hormones. That drop is what drives symptoms for roughly 85% of women in the menopausal transition.

Estrogen therapy supplements your diminished supply, providing hormones that bind to estrogen receptors diffused throughout the body, explains gynecologist Alyssa Dweck, MD, a Menopause Society–certified practitioner and chief medical officer of Bonafide Health. This helps minimize many of the symptoms that accompany menopause.

HRT is not one-size-fits-all. There is a range of doses and routes of administration (oral, transdermal, vaginal), and certain options are better suited for specific symptoms. Depending on what you’re experiencing and your medical history, your doctor might prescribe:

• Systemic HRT: Estrogen taken orally or through patches, gels, or sprays. This is typically used to treat full-body symptoms such as hot flashes, night sweats, and sleep issues.

• Local estrogen therapy: Vaginal rings, tablets, or creams that target symptoms like dryness, irritation, or painful intercourse.

• Combination therapy (estrogen + progestin): Used for people with an intact uterus, this approach treats a broad range of symptoms and helps protect against endometrial cancer.

What does HRT help with?

HRT is highly effective at treating many menopausal symptoms. And considering that at least 20% of perimenopausal women report their symptoms significantly impact their quality of life, HRT can make a marked difference in day-to-day well-being during the transition, both experts agree. 

Most commonly, estrogen or estrogen-progesterone therapy is prescribed to relieve vasomotor symptoms (VMS) like hot flashes and night sweats, along with their downstream effects: disrupted sleep, brain fog, mood swings, and daytime fatigue, Dr. Dweck explains. 

HRT can also help reduce several long-term consequences of estrogen loss, including bone loss, vaginal dryness, painful sex, and recurrent UTIs.

In addition to estrogen and combination therapies, testosterone can be prescribed for off-label use to treat low libido, and progesterone alone is sometimes used for sleep disturbances, Dr. Dweck adds.

Related: Menopause 101

When should you start HRT?

The average age of menopause — defined as 12 consecutive months without a period — in the U.S. is 51 years old. Most women start perimenopause (and begin experiencing menopausal symptoms) between the ages of 45 and 54. 

Since HRT helps with side effects of this transition, you should talk to your doc about HRT as soon as you notice early signs of perimenopause, like the symptoms listed above.

But you don’t need to wait until your mid-40s to start the conversation. Bringing it up with your doctor in your mid-30s and early 40s is often helpful. Asignificant number of women develop perimenopause-related symptoms as early as 30, but they’re usually less-obvious psychological symptoms like anxiety, depression, irritability. Dr. Bachmann notes that in early perimenopause, you may still be getting your period pretty regularly, just with an occasional missed cycle.

After menopause, when estrogen levels drop sharply, the risk for several conditions — including cardiovascular disease, high blood pressure, osteoporosis, certain cancers — significantly increases after menopause.

For years, the medical consensus has been that starting HRT before age 60 and within 10 years of menopause offers the most protection for your brain and heart.

But that new study presented at the Annual Meeting of The Menopause Society says starting HRT even earlier might offer additional benefits. Researchers analyzed more than 120 million patient records and found that women who began estrogen therapy 10 years before they hit menopause avoided the higher rate of breast cancer, heart attack, or stroke — risks that often come after the transition. 

It’s important to note that this study is still awaiting peer review, but Dr. Dweck notes that taking HRT during perimenopause has long been considered acceptable. As always, the decision is highly individualized. 

There’s no harm in talking to your doctor early, Dr. Bachmann adds. If you suspect you’re in perimenopause, even if you’re younger than 45, consider making two appointments with your doc so they have time to draw your blood and confirm.

What are the risks of hormone replacement therapy?

For women in the menopausal transition who are under 60, there are very few downsides to taking hormone replacement therapy, Dr. Bachmann says. “The hormone therapy prescribed isn’t an excessive amount of the hormone. You’re taking a low dose — lower than most hormonal contraceptives — and you’re just replacing what the ovaries naturally produced as the egg matured,” she explains.

Older research suggested that HRT might increase your cardiovascular risk after 65 if your heart already has age-related damage. But a large 2024 study published in Menopause found that the risk varies widely based on the type of therapy, how it’s administered (orally vs. vaginally vs. topically), and the dose, not HRT itself, across the board. 

So why did the FDA previously issue a black box warning? Earlier studies showed that in women over 70, certain forms of HRT were linked to increased cardiovascular issues and some cancers (breast, and possibly ovarian). But those findings were based largely on an older, oral-only formulation that isn’t commonly prescribed anymore, Dr. Dweck adds.

In other words, the FDA was generalizing the risks of one formulation in much older adults to all women and all types of hormone therapy, skewing the perception that HRT was a risk for everyone.

Dr. Dweck says there are a few conditions where systemic hormone therapy is not recommended, including undiagnosed vaginal bleeding, active liver disease, active breast cancer or other hormone-sensitive cancers, existing cardiovascular disease, and potentially anyone with a predisposition to blood clots. 

But because HRT comes inmany forms — and can be tailored by type, dose, and route — it’s worth talking to your doctor about whether hormone therapy is right for you, regardless of your age. 

What to expect if you start HRT

You won’t need regular blood tests to fine-tune your hormone levels — dosing is based on your clinical response, meaning how well your symptoms improve, Dr. Dweck explains. Your doctor will help you choose the right formulation for your needs (oral, transdermal, or vaginal), and tweak dosage based on how your body responds.

It’s also important to know that hormone therapy is not meant to be indefinite. You and your doctor will reassess every year to determine if the benefits still outweigh the risks and whether tapering down might be appropriate.

Related: Thriving Through Menopause

The bottom line on HRT

The FDA’s removal of the black box warning doesn’t mean hormone therapy is right for everyone — but it does mean that for millions of women in their 30s, 40s, 50s, and beyond, the science now aligns with what menopause practitioners have known for years: When timed and dosed right, hormone replacement therapy is safe, effective — and often life-changing.

If you’re experiencing menopause symptoms that are interfering with your quality of life — big or small — it’s worth bringing it up with your doctor. The goal isn’t to “fix” menopause — it’s to help you feel like yourself again. And the science says hormone replacement therapy may be the ticket to do just that.