Bioidentical Hormones: What They Are, Who They’re For, and What to Ask
Clinically written and reviewed by Dr. Hayhlee Clarence, ND, a licensed naturopathic doctor registered with the College of Naturopaths of Ontario (Reg. #3801). Last reviewed October 2026.
Are bioidentical hormones safer? Are they more natural? Do they have to come from a compounding pharmacy? Is hormone therapy even safe at all? If you’ve started researching hormone therapy for perimenopause or menopause, you’ve probably run into a lot of conflicting answers to these questions. Many women give up on the idea altogether because of that confusion, and miss out on a treatment that could make a big difference in how they feel. So let’s look at what we really know.
First, What Is Menopausal Hormone Therapy?
Menopausal hormone therapy (MHT), also often called hormone replacement therapy (HRT), is an umbrella term for the use of estrogen and (most often) progesterone in women going through perimenopause and menopause. As we move through this transition, our ovaries produce less and less of these hormones. MHT replaces some of what’s been lost, with the goal of improving symptoms. The big ones are vasomotor symptoms (think hot flashes and night sweats), insomnia, and mood changes.
What Can MHT Address?
My goal is always to help patients feel like themselves again. So often, women lose their sense of self as they spiral through symptoms that challenge their ability to function at home, at work, and in their relationships the way they used to.
I like to divide MHT into two categories: systemic hormone therapy and local hormone therapy.
Systemic hormone therapy means hormones that circulate throughout the whole body. It has the strongest evidence for treating hot flashes and night sweats, which remain the main reason to start treatment. That said, many women also see improvements in:
Insomnia
Mood changes
Joint pain
Brain fog
Low libido
Local hormone therapy means hormones applied directly to vaginal tissue. It mainly addresses the genitourinary syndrome of menopause (GSM), which includes:
Vaginal dryness, itching, or sensitivity
Pain with intercourse
More frequent yeast infections, or feeling like you’re getting one
Pelvic floor weakening, like a feeling of heaviness that gets worse over time
Changes in bladder control: more urgency or frequency, feeling like you can’t fully empty your bladder or needing to go again less than 5 minutes after you just went, leaking, or waking more often at night to urinate
The majority of women will experience symptoms of GSM after menopause. Not everyone will need hormone therapy for it, but most women never bring it up with their doctor. So pay attention, and flag it if you notice symptoms that are affecting your life!
Who Is MHT For?
MHT is primarily for women with perimenopause or menopause symptoms that are affecting their quality of life, with hot flashes and night sweats being the most common reason to start. For most healthy women, the benefits are most likely to outweigh the risks when MHT is started before age 60, or within 10 years of their last period.
MHT isn’t the right fit for everyone. It’s generally not recommended for women with a history of breast cancer, blood clots, stroke, heart attack, active liver disease, or unexplained vaginal bleeding. This is exactly why the decision should always be made with a doctor who knows your full health history.
“Do You Use Bioidentical Hormones?”
This is one of the most common questions I get once a woman has decided she wants to consider MHT, and it’s also one of the biggest sources of confusion I see in practice.
So What Are Bioidentical Hormones, and Why Do They (Sometimes) Matter?
When MHT was first introduced, the most common form of estrogen used was conjugated equine estrogen (CEE). CEE is a combination of at least 10 different estrogens derived from the urine of pregnant horses. The most common form of progesterone was a progestin, which is a human-made (synthetic) chemical that mimics the effects of progesterone.
Then came bioidentical hormones! Women could now use 17-beta-estradiol, which has the exact same chemical structure as the estrogen made by our ovaries. They could also switch from progestins to progesterone, which is identical in structure to the progesterone our ovaries produce naturally.
Today, the preferred way to prescribe MHT is:
17-beta-estradiol, as a patch or a gel
Micronized progesterone, as a capsule taken orally
Why Is Estrogen Preferred as a Patch or a Gel?
When estrogen is absorbed through the skin (meaning it’s “transdermal”), it carries a lower risk of blood clots and stroke than estrogen taken by mouth. This makes it a safer option overall. It also makes it a better fit for women who choose to stay on MHT longer-term. With oral estrogen, we’re more cautious and reassess the risks more closely over time.
Why Is Micronized Progesterone Preferred Over Progestins?
There’s growing evidence that progestins increase breast cancer risk more than micronized progesterone does. To keep breast cancer risk as low as possible, progesterone is the preferred option.
A Few Common Misconceptions About Bioidentical Hormones
“Bioidentical hormones have to be compounded by a pharmacy.” Not true! There are great Health Canada approved options available. For estrogen, there are patches (Estradot or Climara) and gels (Estrogel or Divigel). For progesterone, there’s Prometrium.
“Bioidentical means natural.” Progesterone and 17-beta-estradiol are initially derived from yam and soy plants, but they’re refined in a lab before we use them. “Bioidentical” refers to the structure of the hormone, meaning it matches what your body makes. It doesn’t mean the hormone is natural.
“If some is good, more is better.” Dosing is not a more-is-better situation! Here’s a common example. A woman has been on MHT for 6+ months with good control of her symptoms, and then her symptoms return or flare. She assumes she needs a higher dose. This is where detailed problem-solving can be really helpful, because many things can affect how well MHT is working:
Changes in weight
Where the patch is placed
How the gel is being applied
A recent illness or major stressor
Before jumping up a dose, make sure there isn’t a problem that needs solving first. Otherwise, you may find the higher dose has no added effect, and a few more months of symptoms later you’re back to asking these same questions.
What MHT Won’t Do
Help you lose weight.
Fix every symptom you’re experiencing. MHT often resolves 2 to 3 key symptoms, but it may not solve every problem.
What to Ask Your Doctor For
Most prescribers will start MHT with an estradiol patch and progesterone capsules, but it’s always worth confirming that you’re getting:
Progesterone capsules, not a progestin
Estradiol, not a conjugated estrogen combination, as a patch or a gel
It’s OK to Choose What’s Right for You (Even If It’s Not Right for Someone Else)
For some women, estrogen through the skin doesn’t manage their symptoms, is hard to use consistently, or is too expensive compared to oral estrogen. Sometimes oral estrogen is the best choice! Understanding why, and knowing which side effects to watch for, means you can still get the long-term benefits safely.
For other women, progesterone causes side effects severe enough that they can’t tolerate it. There are still options:
Vaginal estrogen. If your symptoms are mainly vaginal or bladder-related, low-dose vaginal estrogen doesn’t need progesterone alongside it.
A hormonal IUD. It can protect your uterus while you use estrogen.
Estrogen combined with a uterus-protecting medication. This lets you use estrogen without taking progesterone at all.
Whatever you choose, make sure you have all the information, and that your doctor knows your personal and family history well before you make a decision together. And if one option isn’t working, it’s OK to try something else!
Ready to make a change?
Wondering whether hormone therapy is right for you, or already taking MHT and not seeing the results you hoped for? Learn more about bioidentical hormones at The Clara Clinic, or book a complimentary 15-minute consultation to explore your options and determine the next steps for your care.
In support of your health,
Dr. Hayhlee Clarence, ND
Frequently Asked Questions About Bioidentical Hormones
Are bioidentical hormones safer than traditional hormone therapy?
Bioidentical hormones have the same molecular structure as hormones naturally produced by the body, but that doesn't automatically make them safer. Safety depends on the type of hormone, dose, how it's administered, and your personal health history. Health Canada-approved estradiol and micronized progesterone are commonly used options, and transdermal estrogen may have a lower risk of blood clots than oral estrogen.
Do bioidentical hormones have to be compounded?
No. There are Health Canada-approved bioidentical hormone medications available, including estradiol patches and gels and oral micronized progesterone. Compounded hormone preparations are generally not recommended when an appropriate approved product is available, as they may lack the same level of quality control and safety evidence.
Can bioidentical hormones help with perimenopause symptoms?
Yes. Menopausal hormone therapy can help manage symptoms such as hot flashes and night sweats during perimenopause and menopause. Some women may also experience improvements in sleep and other symptoms, although results vary. A healthcare provider can help determine whether hormone therapy is appropriate based on your symptoms and medical history.
Do I need progesterone if I'm taking estrogen?
If you have a uterus and are using systemic estrogen, you generally need progesterone or another form of endometrial protection to reduce the risk of endometrial cancer. Low-dose vaginal estrogen used for localized symptoms typically does not require additional progesterone. Your prescriber can recommend the appropriate treatment combination.
Will bioidentical hormones help with weight gain during menopause?
Bioidentical hormone therapy is not a weight-loss treatment. Although it can improve certain menopause symptoms that affect sleep and daily functioning, it does not directly produce meaningful weight loss. Changes in body composition during menopause may require a broader approach to care.
How do I know if bioidentical hormone therapy is right for me?
The decision depends on your symptoms, age, medical history, personal preferences, and individual risk factors. Hormone therapy may be an effective option for women experiencing disruptive perimenopause or menopause symptoms, but it isn't appropriate for everyone. A consultation with a qualified healthcare provider can help you understand the potential benefits, risks, and alternatives.