Estrogen: What It Is and What It Does

Estrogen is not just one hormone. Your body actually makes different types of estrogen, and each one plays a unique role in your health.

Understanding these differences helps explain symptoms, cancer risk, weight changes, and why hormone balance matters—especially as we age.

 

The Three Main Types of Estrogen

​

Estrone (E1)

Estrone is a weaker form of estrogen and becomes the dominant estrogen after menopause.

It is produced in:

• The ovaries

• Adrenal glands

• Liver

• Fat tissue

Estrone can be converted into estradiol, which makes it a kind of backup or reserve estrogen.

However, when estrone levels are too high—especially relative to progesterone—it may increase the risk of breast and uterine cancers. This is because estrone tends to activate growth-promoting estrogen receptors.

​

Estradiol (E2)

Estradiol is the strongest and most active estrogen in the body.

It is mainly produced by the ovaries, but also by:

• Fat cells

• Adrenal glands

• Conversion from estrone

Estradiol is responsible for:

• Breast development

• Widening of the hips

• Female fat distribution

• Regulation of the menstrual cycle

• Healthy vaginal and uterine tissue

It also plays important roles in:

• Bone strength

• Skin health

• Brain function

• Mood and memory

• Cardiovascular health

Estradiol interacts with both growth-stimulating and growth-regulating estrogen receptors, which is why balance is critical.

​

Estriol (E3)

Estriol is the weakest estrogen, but it may also be the most protective.

It is the primary estrogen during pregnancy, produced by the placenta and fetus. Estriol levels rise steadily throughout pregnancy and peak in the third trimester.

Researchers have observed that some autoimmune conditions—such as multiple sclerosis and rheumatoid arthritis—often improve during pregnancy when estriol levels are highest. This has led to ongoing research into estriol’s potential immune-modulating and anti-inflammatory effects.

Estriol primarily activates estrogen receptors that limit tissue growth, which may explain why it is thought to be more protective against estrogen-related cancers.

​

Why Estrogen Balance Matters

Symptoms are not caused by estrogen alone, but by:

• Too much estrogen

• Too little estrogen

• Or an imbalance between estrogen and progesterone

Estrogen must also be metabolized safely by the liver and gut. Poor estrogen metabolism can increase inflammation, cancer risk, and hormone-related symptoms.

​

Our Approach

Knowledge is key. We help you understand:

• How estrogen affects your daily life

• Which estrogen patterns may be contributing to symptoms

• How to restore balance—not just suppress symptoms

Our goal is to support:

• Healthy estrogen levels

• Safer estrogen metabolism

• Long-term hormonal and metabolic health

​

Bottom line for patients:

Estrogen isn’t “good” or “bad.” The type, amount, balance, and metabolism of estrogen all matter.