If you’re a woman of reproductive age, you should be making estrogen with every menstrual cycle. Estrogen is essential for healthy mood, bone, muscle, and metabolism.
Signs you’re making enough estrogen include cervical fluid and regular ovulation.
Signs of low estrogen include absent periods and vaginal dryness.
Healthy blood levels of estrogen
Your main estrogen is estradiol, and it fluctuates throughout your menstrual cycle:
- Early in the cycle (day 2 or 3): Estradiol is low, typically below 50 pg/mL (180 pmol/L). That’s a menopausal-level reading, but it’s completely normal at that stage of the cycle.
- Just before ovulation (around day 10 of a 28-day cycle): Estradiol should rise to between 200 and 400 pg/mL (700–1400 pmol/L).
You make estrogen by starting the journey to ovulation
If your estradiol is low, the first question to ask is: Are you ovulating regularly?
If you are ovulating, then you’re making enough estradiol—ovulation can’t happen without it.
If you’re not, the next question is: “Can you still ovulate? Or are you in menopause?”
Menopause—or primary ovarian insufficiency (if under 45)—is typically diagnosed with two FSH readings (taken at least one month apart) higher than 40 IU/L.
- If FSH is > 40 IU/L twice, you’re in menopause.
- If FSH is < 40 IU/L, you’re not in menopause and still have the potential to ovulate. That’s true even if 1) you’ve had a partial hysterectomy (uterus removed), or 2) you’re in perimenopause (which is initially a state of high, not low, estrogen).
If you can still ovulate—but aren’t—ask why not?
If you’re not ovulating, the goal is to identify and address the obstacle. Some common reasons include:
- Being on birth control (which suppresses the ovaries and estradiol production)
- PCOS
- Undereating or hypothalamic amenorrhea
- A problem with gluten
- High prolactin
- Thyroid dysfunction, chronic stress, and more
For a full discussion of obstacles to ovulation, see Chapter 7 of my book Period Repair Manual.
Once you identify your obstacle, simply correct it, and your estradiol should rise dramatically. That’s all you need to do.
What about menopause?
With menopause, your ovaries naturally make far less estradiol than they used to, so your estradiol will be low on a blood test. You will, however, continue to make some estrogen inside every cell, and since menopause is a natural life phase, your body can adapt to the lower (mostly intracellular) estrogen.
For more, see my book Hormone Repair Manual, which includes a full discussion of perimenopause, menopause, and the option to take body-identical estradiol if needed.
Do phytoestrogens increase estrogen?
It depends on your life stage:
- Before menopause: Phytoestrogens from foods like soy or flaxseed usually have a mild and beneficial anti-estrogen effect. They essentially lower estrogen.
- After menopause: Phytoestrogens can exert a mild pro-estrogen effect by gently stimulating estrogen receptors, which may offer symptom relief.
