Is Estriol Safer Than Estradiol?

August 19, 2021

Is Estriol Safer Than Estradiol?

Estriol and estradiol are two of three forms of estrogen produced in the body. Each kind of estrogen has a purpose, and the amounts of each type fluctuate throughout a woman's monthly cycle and age. Estriol and estradiol are used in hormone replacement therapy (HRT) and bioidentical hormone replacement therapy (BHRT) to help ease menopausal symptoms. 

Some people wonder if one form is safer than another. So the question becomes, is estriol safer than estradiol? The short answer is that estriol is the safest form of estrogen, but the other forms are healthy when used correctly. 

Different Forms of Estrogen

Estrogen is a female hormone produced mostly in the ovaries. Smaller amounts of estrogen are synthesized in the brain, liver, heart, muscle, and bone. Estrogen, along with progesterone, helps regulate the menstrual cycle and fertility. 

But it also has non-reproductive effects on bone, cognitive, and cardiovascular health. Within estrogen, there are three forms that play different roles in a woman's cycle and life, including:

  • Estrone (E1)
  • Estradiol (E2)
  • Estriol (E3)

Estrone, also called oestrone, is the type of estrone produced primarily after menopause. It's the least potent of the three estrogens and often becomes a repository for estradiol and estriol. As a repository, estrone can convert to the other estrogens as needed. 

Estradiol is the most robust kind of estrogen. Its production is crucial for menstruation, and low amounts signal the end of the productive years for women. The sharp decline results in menopausal symptoms, such as hot flashes, weight gain, moodiness, and others. Hormone replacement therapy (HR) commonly uses estradiol in pill and topical form to alleviate menopausal symptoms. 

Estriol is always produced, but amounts increase during pregnancy. Often nicknamed the pregnancy hormone, estriol increases with the pregnancy and peaks when giving birth. It helps prepare the body for breastfeeding and giving birth. 

Main Differences Between Estriol and Estradiol

Estriol and estradiol are highly similar but do have distinct differences in the body. The first main difference comes in the structure of the hormone. Estriol has three oxygen-hydrogen receptors, and estradiol has two. 

Estradiol is more potent and active in the body than estriol. Estriol plays a vital role during pregnancy, and the placenta produces increased amounts; whereas, estradiol primarily comes from the ovaries. 

Estriol is the most prominent circulating hormone yet has fewer functions than estradiol. Estradiol can attach to receptors throughout the entire body, while estriol has a few, mainly in the vagina, hair follicles, and skin. 

Health Conditions Treated By Estradiol and Estriol

Both estradiol and estriol are used in hormone replacement therapy (HRT) and bioidentical hormone replacement therapy (BHRT) to treat different symptoms. Both HRT and BHRT help mitigate menopausal symptoms, including:

  • Hot flashes
  • Night sweats
  • Weight gain
  • Low libido
  • Insomnia
  • Moodiness
  • Vaginal atrophy
  • Dry skin
  • Depression and anxiety

Besides menopausal symptoms, estrogen can also treat other medical concerns for women not going through menopause. For example, estrogen plays a vital role in bone development and density. Low levels can decrease bone density and increase the risk of osteoporosis. 

Estrogen also helps keep hearts healthy and low levels can increase the chance of heart disease. Also, one outcome of less estrogen can cause weight gain. Gaining weight can result in obesity, which is linked to diabetes and heart disease. Women not going through menopause can take the forms of estrogen to help with these conditions. Speak to your doctor about hormone therapy.

Difference between HRT and BHRT

In essence, both are doing the same thing in the body— increasing hormone levels. The idea is to replace the missing estrogen with natural ones. But there are some distinct differences.

Bioidentical hormones are chemically the same as the hormones estriol and estradiol made in the body. However, traditional HRT is not similar. The reason is the BHRT uses hormones derived from plant estrogens. While the hormones in HRT come from pregnant horse urine and other synthetic hormones.

Many BHRT supporters assert that bioidentical hormones are safer due to the "identical" and "natural" makeup of the hormones used in the treatment. Also, bioidentical hormones can come from compounding pharmacies, which create a mixture specifically for the patient and prescribed by a doctor.

What is More Effective— Estriol or Estradiol?

As mentioned, estradiol is the most potent form. It's the most commonly used form of estrogen to combat menopausal symptoms and is typically used in traditional HRT. This is because it's the most robust form, and the body has the most receptors for this type of estrogen. 

Yet estriol is commonly included in BHRT, and some say it has the same effect as estradiol, but since it's less powerful, it may have more minor side effects on the body. Regardless, both are proven to reduce menopausal symptoms, increase bone health and cardiovascular function. 

Is Estriol Safer Than Estradiol?

The debate around hormone replacement therapy is ongoing. Of course, as with taking any supplement, there are always some risks. But research shows that estriol is safer and has fewer side effects than estradiol but still can be highly effective.

Estriol is safe to use with minimal side effects when taken for a short period. Reviews of the Women's Health Initiative (WHI) Study revealed that women not more than 10 years past menopause didn't have an increased risk for strokes, blood clots, and breast cancer as initially thought. Estriol is an effective hormone for balancing hormones.

How to Begin Hormone Therapy?

Hormone therapy with estriol is simple. The first step is to make an appointment with your doctor to have your hormone levels tested. This will confirm that your estrogen levels are low, and this confirmation will help you make the next step. 

Estriol comes in different forms, but the best form is in a transdermal or topical cream. BioLabs Pro offers the most robust and most effective estriol cream on the market. It's produced and developed in the United States to the highest quality and standards. 

Supplementing with an estriol cream is safe and effective. It's safer than estradiol and comes without a prescription. You simply apply the prescribed amount of cream once a day. 

Now is the time to improve your overall well-being. Hormone replacement will always be controversial to some degree but what isn't is your quality of life.