Estrogen: What You Need to Know About This Essential Hormone
One of my favorite hormones is estrogen, and there’s a lot of confusion out there about estrogen—what the levels should be, what’s too high or too low—and that confusion exists even among some healthcare providers. So let’s break it down in a way that makes sense and empowers you to better understand your body.
What Is Estrogen and Where Does It Come From?
Estrogen is primarily made by the ovaries, and it's vital to how our bodies function. You may not realize this, but your body makes three types of estrogen:
Estrone (E1): Made in fat cells
Estradiol (E2): Made in the ovaries—this is the dominant estrogen during your reproductive years
Estriol (E3): Made by the placenta—this one’s specific to pregnancy
During your reproductive years, estradiol (E2) is the main player, and it’s made by the growing follicle in the ovary. Unless you’re on hormonal contraception, pregnant, or breastfeeding, your estrogen levels should fluctuate naturally throughout your cycle.
How Estrogen Changes Throughout the Menstrual Cycle
Every month, a group of eggs comes out of the vault (yes, your ovaries store them like a vault!). Each egg is inside a follicle, and your brain sends out follicle-stimulating hormone (FSH) to help one follicle grow. As that follicle matures, it produces more estradiol.
Let me give you some numbers for perspective:
Small follicles may make ~1 picogram of estrogen each
A mature follicle can produce ~200 picograms
So if you start with 20 follicles, your baseline estrogen might be around 20 pg/mL, but that can rise significantly as one dominant follicle grows and gets ready to ovulate.
When estrogen peaks, your brain releases luteinizing hormone (LH) to trigger ovulation. After ovulation, that follicle becomes the corpus luteum, which produces progesterone and estrogen. If you’re not pregnant, both hormones drop, your period arrives, and the cycle starts again.
How Estrogen Makes You Feel
Estrogen impacts how you feel, and most of us can intuitively sense its rise and fall:
When Estrogen Is High (Follicular Phase):
Increased concentration
Higher energy
Elevated libido
Cervical mucus increases
Possible breast fullness/tenderness
When Estrogen Drops (Late Luteal/Before Period):
Mood changes
Brain fog
Vaginal dryness
Lower libido
Difficulty sleeping
These cyclical symptoms are normal, but if your period is predictable and regular, that’s one of the best signs your hormones are in balance.
Signs of Low Estrogen
Sometimes, your estrogen isn’t just fluctuating—it stays chronically low. This can happen due to:
Lack of ovulation
Ovarian failure (menopause)
Extreme stress
Surgical removal of ovaries
Symptoms of chronic low estrogen include:
Hot flashes/night sweats
Brain fog
Vaginal dryness
Low libido
Depression
Risk of osteoporosis, Alzheimer’s, and heart disease
This is why it’s not healthy to go without a period for long periods—unless it’s due to hormone contraception that replaces your hormones.
The Perimenopause Transition
Perimenopause is often misunderstood and under-treated. It’s the transition period before menopause, and you might notice your cycles spreading out to every 2–4 months. During this time, your body has more low estrogen days, which can be rough.
If this is your experience, hormone replacement therapy may be beneficial. Don’t just assume you have to suffer through it.
What About High Estrogen?
Now, let’s talk about the flip side—high estrogen, or what’s often referred to as estrogen dominance.
This can happen naturally during the follicular phase, but persistent high levels outside of this are concerning. Some common causes include:
PCOS: More follicles = more baseline estrogen
Obesity: Fat cells make more estrone (E1)
Heavy alcohol use or liver dysfunction
Ovarian tumors or environmental toxins
Symptoms of high estrogen can mimic other hormone imbalances:
Fatigue
Hormonal acne
Breast enlargement
Sleep issues
Mood changes
Weight gain around the midsection
Insulin resistance
Even your gut health and liver function play a role in how estrogen is metabolized. That’s why what you eat, how you manage stress, and your overall health all matter.
Final Thoughts: It’s About the Root Cause
If your periods are regular, that’s a great sign. If they’re not, and you’re experiencing any of these symptoms, don’t jump straight to supplements, especially from people selling their own product.
You need to understand the root cause of the imbalance. Hormones are complex, and your health deserves nuance, not a one-size-fits-all fix.
