Estriol vs Estradiol: Differences, Menopause Uses, and How Creams Compare

Estriol and estradiol are both forms of estrogen, but they’re not the same, and that difference matters a lot during menopause. Estrogen isn’t just one hormone. It’s a family of related hormones that have different strengths, roles, and effects in the body. Estradiol (often called E2) is the main and most powerful estrogen in people before menopause. Estriol (E3) is much weaker and plays a bigger role during pregnancy, with smaller roles at other life stages.

When it comes to menopause treatment, this difference shows up clearly. Estradiol is generally the more potent option and is the estrogen used in most approved menopause hormone therapies in the U.S. It’s well-studied, widely prescribed, and available in many forms, including pills, patches, gels, rings, and vaginal creams. Estriol, on the other hand, is often described as “lower potency” or “gentler” and is most commonly discussed in the context of localized vaginal use, especially outside the U.S. or in compounded products.

The TL;DR is that estradiol is usually the go-to estrogen for whole-body menopause symptoms like hot flashes, while estriol is more often positioned as a lower-strength option for targeted vaginal symptoms. 

If you’re curious about how estradiol is used locally, you can learn more about Evvy’s Estradiol Vaginal Cream, which is designed specifically for vaginal and urinary menopause symptoms.

What is the difference between estriol and estradiol?

Estriol and estradiol are both endogenous estrogens, meaning your body makes them naturally. But they differ significantly in strength, timing, and what they actually do in the body. Understanding these differences helps explain why they’re used so differently in menopause care.

Estradiol is the principal and most potent estrogen in premenopausal women. It’s mainly produced in the ovaries and is responsible for regulating the menstrual cycle, maintaining bone density, supporting brain and cardiovascular health, and keeping vaginal and urinary tissues healthy. Estradiol binds strongly to both major estrogen receptors (known as ER-alpha and ER-beta), which is why it has such broad, whole-body effects. Due to its strong receptor activity, estradiol is the main form of estrogen used in hormone replacement therapy (HRT) or menopausal hormone therapy (MHT).

Estriol is quite different. It’s considered a “weak” or sometimes “impeded” estrogen. Outside of pregnancy, estriol levels are low. However, during pregnancy, estriol becomes the main estrogen and is produced in large amounts by the placenta. Estriol does not bind to estrogen receptors, especially the ER-alpha type, as strongly as estradiol does. This means that estriol affects the body in milder and more localized ways compared to estradiol, which has stronger effects on tissues like the uterine lining.

Estriol (E3): the “weaker” estrogen

Estriol is often considered the mildest among the three main natural estrogens (estradiol, estrone, and estriol). It has a lower potency at estrogen receptors and a shorter half-life in the body, which means it doesn’t stick around for long. Normally, outside of pregnancy, estriol is found in low levels in the body and doesn’t produce significant estrogen effects.

In the context of menopause care, estriol is frequently used in topical or vaginal forms to help with issues like dryness, irritation, and urinary symptoms. Since it has a much gentler effect on the uterine lining compared to estradiol, it’s sometimes labeled as “gentler.” However, just because it’s milder doesn’t necessarily mean it’s always safer or the best choice for everyone. Estriol is still an estrogen and can influence estrogen-sensitive tissues, especially with long-term or higher doses.

Estradiol (E2): the “main” estrogen in menopause treatment

Estradiol is the main form of estrogen found in women who aren’t pregnant and are premenopausal. It plays a big role in creating the beneficial effects of estrogen throughout the body, influencing everything from our bones and brain to our skin and vaginal tissue. Because it binds well to estrogen receptors, it’s especially effective at treating menopausal symptoms that arise from declining estrogen levels.

When it comes to managing menopause, estradiol is the most researched and commonly prescribed form of estrogen. It’s approved by the FDA and comes in a variety of options, like oral tablets, transdermal patches, gels, sprays, vaginal creams, tablets, and rings. This variety means healthcare providers can customize treatment based on individual symptoms, risk factors, and personal preferences. Overall, estradiol is often seen as the gold standard for easing hot flashes, night sweats, and other menopause-related symptoms.

Is estriol the same as estrogen?

This is a really common source of confusion. Most of us say “estrogen” as if it’s a single thing, but estrogen is actually a category of hormones. Estradiol, estriol, and estrone are all estrogens, but they’re not interchangeable.

When someone asks whether estriol is “the same as estrogen,” the most accurate answer is yes and no. Yes, estriol is an estrogen. But no, it’s not the same as estradiol, which is what most people mean when they talk about estrogen in the context of menopause treatment.

The confusion matters because products labeled simply as “estrogen cream” or “natural estrogen” may contain very different hormones with very different strengths. Estradiol has strong, predictable effects throughout the body and is backed by decades of research. Estriol has milder effects and is often used for specific, localized goals, like improving vaginal tissue health.

Understanding estrogen as a family of hormones helps explain why two estrogen products can behave so differently. It also helps explain why medical guidelines usually specify the exact estrogen being used, rather than just saying “estrogen.”

Estriol vs estradiol for menopause: Which estrogen works best for which menopause symptoms?

As estrogen levels decrease in menopause, many people have different symptoms (and with different intensities). These can include hot flashes, night sweats, vaginal dryness, painful sex, trouble sleeping, mood swings, and bone loss. Not all types of estrogen treat all symptoms in the same way, and the “best” one depends largely on your symptoms. 

Vaginal dryness, burning, irritation, and painful sex

Both estriol and estradiol can be effective for genitourinary syndrome of menopause (GSM), which includes vaginal atrophy (dryness), irritation, burning, pain with sex, and some urinary symptoms. When used vaginally at low doses, both hormones help restore vaginal tissue thickness, elasticity, and moisture. Vaginal estrogen treatments can also restore healthy bacteria to the vaginal microbiome, which commonly shifts in menopause.

In practice, low-dose vaginal estradiol is the standard option in many guidelines, especially in the U.S., because it’s FDA-approved, well-studied, and highly effective with minimal systemic absorption. Estriol vaginal products are widely used in some countries and are often chosen when a very low-potency, mostly local effect is desired. Studies suggest that estriol can improve vaginal health without significantly stimulating the uterine lining.

Hot flashes and other whole-body menopause symptoms

Estradiol is known for being really effective when it comes to managing vasomotor symptoms. Some studies suggest it can reduce these symptoms by around 75%, often within just a couple of weeks. Plus, it can provide some nice added benefits for sleep, mood, and even bone health. 

Estriol, meanwhile, isn’t as strong when it comes to tackling those whole-body symptoms. While some research shows estriol might help a bit, it typically doesn’t have the same impact as estradiol for serious hot flashes or for bone health. So for those experiencing bothersome systemic symptoms, estradiol is usually the go-to choice for more reliable relief.

Estriol cream vs estradiol vaginal cream: What’s different in day-to-day use?

From a daily-life perspective, estriol and estradiol creams can feel similar, but there are some practical differences worth knowing about. Both are typically applied vaginally using an applicator, and both are often used at bedtime to reduce leakage.

Estradiol creams are standardized prescription products with clearly defined dosing. Estriol creams in the U.S. are often compounded, which can mean more variability in strength and consistency. Some people like the idea of estriol because it’s lower potency, while others prefer estradiol because dosing and effects are more predictable.

What people notice with creams (pros and cons)

• Dosing flexibility: Creams allow dose adjustments, but compounded estriol may vary more than standardized estradiol. 
• Leakage: Both can feel messy at first, especially early in treatment. 
• Timing around sex: Many people prefer applying at night and avoiding sex shortly after. 
• Sensitivity or irritation: Either hormone can cause initial irritation, especially if the base isn’t well tolerated. 
• Internal vs external use: Some plans include internal vaginal use plus external vulvar application. 
• Consistency: Estradiol products tend to be more uniform from tube to tube. 
• Absorption: Estradiol absorption and effects are better studied. 
• Convenience: Some people prefer creams, others switch to vaginal tablets or rings over time.

Estriol vs estradiol: Potency and how long it lasts

Potency is a measure of how effectively a hormone activates estrogen receptors and influences tissues. Estradiol is the strongest natural estrogen. It works well with both ER-alpha and ER-beta receptors. That’s why even small amounts of estradiol can have significant effects.

Estriol is far less potent. It binds more weakly to receptors and is cleared from the body more quickly. This shorter duration is part of why it’s often described as gentler, but it also means it may need more frequent dosing to maintain effects.

“Lasting longer” doesn’t necessarily mean better, though. Estradiol’s longer-lasting, stronger activity is exactly what makes it effective for systemic menopausal symptoms, but estriol’s shorter action can be useful when the goal is a localized effect with minimal systemic exposure. This goes to show why it’s so important for menopause care to be individualized based on your symptoms, lifestyle, and medical history.

Which estrogen is safer during pregnancy: Estriol or estradiol?

It’s understandable why this question comes up. Estriol is the dominant estrogen during pregnancy and is produced in large amounts by the placenta, where it helps support the uterus and prepare the body for childbirth and breastfeeding.

But this is an important distinction: the fact that estriol is naturally present in pregnancy doesn’t mean estrogen therapy is recommended during pregnancy. Outside of very specific, rare medical circumstances managed by specialists, estrogen treatment of any kind generally isn’t used in pregnancy. This applies to estriol, estradiol, and all other forms of estrogen.

Estradiol is also naturally present during pregnancy, but like estriol, it is not routinely prescribed as a medication. Taking supplemental estrogen during pregnancy can interfere with normal hormonal signaling and fetal development, which is why it is avoided unless there is a clear, medically necessary reason.

The key takeaway is that pregnancy safety should never be used as a reason to choose one estrogen over another. Menopausal hormone therapy is intended only for people who aren't pregnant, and the safety considerations for pregnancy and menopause are completely different.

FAQs about estriol vs estradiol

Estriol cream vs estradiol cream: which is better for menopause symptoms?

It really depends on which menopause symptoms you’re targeting. For vaginal dryness, irritation, burning, or pain with sex, both estriol and estradiol creams can be effective when used vaginally. That said, low-dose vaginal estradiol is the standard option in many medical guidelines. If symptoms go beyond reproductive health — such as hot flashes, sleep disruption, or mood changes — systemic estradiol is far more effective. Estriol is much weaker and generally isn’t used for whole-body menopause symptoms.

Is estriol the same as estrogen?

Estriol is an estrogen, but it’s not the same as estrogen in the way the term is often used. Estrogen is a broad category of hormones that includes estradiol, estrone, and estriol. Estradiol is the most potent and most active estrogen in nonpregnant adults, while estriol is much weaker. When people say “estrogen therapy,” they’re usually referring to estradiol, which is why this distinction matters when comparing products or treatments.

What is the difference between estriol and estradiol?

The biggest differences are strength, timing, and clinical use. Estradiol is the primary and most potent estrogen in nonpregnant adults and is the backbone of modern menopause hormone therapy. It has strong effects throughout the body and is used to treat hot flashes, night sweats, and bone loss, as well as vaginal symptoms. Estriol is far weaker, becomes dominant mainly during pregnancy, and is usually used in low-dose, localized vaginal treatments rather than systemic therapy.

Which is safer, estriol or estradiol?

Neither estriol nor estradiol is completely risk-free. Estriol’s lower potency and frequent use as a local vaginal therapy may mean less systemic hormone exposure in some cases, which can be appealing for people with specific risk concerns. Estradiol is stronger, so systemic forms have clearer, dose-dependent risks, but those risks are also well studied and better defined. Overall safety depends on the dose, how the hormone is delivered (local vs systemic), how long it’s used, and a person’s individual health history. Both estriol and estradiol can cause side effects such as menstrual changes, breast tenderness, nausea, and more serious risks like blood clots and heart attack.

Who should not take estriol?

Estriol may not be appropriate for people with a history of estrogen-dependent cancers (such as certain breast cancer or endometrial cancer), unexplained vaginal bleeding, or specific medical conditions where estrogen is contraindicated. Even though estriol is weaker, it is still an estrogen and can affect hormone-sensitive tissues. Decisions about using estriol should always be made with a healthcare provider who can weigh personal risk factors and symptoms.

Does estriol cause weight gain?

There’s no strong evidence that estriol specifically causes weight gain. Weight changes during midlife and menopause are common, but they’re influenced by many factors, including aging, changes in metabolism, muscle mass, exercise levels, sleep, and overall hormone shifts (not one estrogen alone). Some people notice body changes during hormone therapy, but research hasn’t shown estriol itself to be a direct cause of weight gain.