What is progesterone? The hormone every woman over 45 needs to know

If you're approaching menopause or already in the thick of it, you've probably heard plenty about declining estrogen levels. But there's another hormone that deserves just as much of your attention, and it might be the missing piece in how you're feeling. Understanding what progesterone is and how it fits into hormone replacement therapy (HRT) can help you make smarter choices about your health.

What is progesterone, exactly?

Progesterone is a hormone your body naturally produces during your reproductive years. In a typical menstrual cycle, it rises after ovulation and prepares the uterine lining for either pregnancy or your monthly period. As you move through perimenopause and into menopause, progesterone levels drop. That shift can affect everything from your sleep to your mood to your overall sense of wellbeing.

"Estrogen gets most of the attention, but progesterone is essential, too," says Felice Gersh, MD, a board-certified integrative gynecologist and founder of the Integrative Medical Group of Irvine.

Testosterone for Women? Doctors Say It May Help After 40

The role of progesterone in menopause

Here's the thing about HRT, also known as menopausal hormone therapy (MHT): If you still have your uterus and you're taking systemic estrogen, you need progesterone (or a related progestin) right alongside it. "In menopause care its main job is to protect the uterine lining," Dr. Gersh explains. Estrogen and progesterone work as a team. 

Without that protection, estrogen alone can cause the uterine lining to overgrow, which may lead to abnormal bleeding and, over time, increase the risk of uterine cancer, she says. 

Two common ways progesterone is prescribed

There isn't just one way to take progesterone, and finding the option that works best for you may take a little trial and error.

Nightly oral progesterone

"This is a common approach and can be a simple, safe choice, especially for women who prefer a bleed-free routine," Dr. Gersh says. "Because oral progesterone is processed through the liver into calming, sedating compounds, some women find it actually helps them sleep better. Others, though, wake up feeling groggy, foggy, moody or just ‘not themselves' the next day."

Cyclic progesterone

This option involves taking progesterone for 14 days each month, followed by 14 progesterone-free days, while continuing estrogen daily, Dr. Gersh explains. "This schedule more closely resembles the body's natural monthly rhythm," she adds. "In my practice, many women feel clearer and more energized when progesterone is cycled rather than taken continuously."

Benefits-and drawbacks-worth knowing

The good news is that the benefits of progesterone are real: uterine protection, better sleep for some women and a more balanced hormone therapy regimen overall. Many women feel like themselves again once they find the right approach.

But the drawbacks are worth knowing, too. Grogginess, brain fog, mood changes and next-day fatigue can affect your quality of life, and those side effects aren't something you should just push through.

"Progesterone is an essential part of menopausal hormone therapy for most women, but it should not be treated as one-size-fits-all," Dr. Gersh says.

Tired of Hot Flashes and a Low Sex Drive? Hormone Pellet Therapy May Help

The bottom line on progesterone 

"If you have a uterus and take estrogen, don't stop progesterone on your own," Dr. Gersh cautions. But if your current routine leaves you feeling anxious, sleepy or foggy-brained, talk to a menopause-trained clinician. Adjusting your hormone balance could make all the difference in how you feel every day.

Ready for more inspiration? Subscribe to our YouTube channel for video podcasts, health tips and uplifting stories designed for women 40, 50, 60 and beyond.

More health news:

Symptoms of Menopause No One Warns You About-From Itchy Ears To Disappearing Labia Minora

Hormone Replacement Therapy May Protect Your Vision During Menopause and Reduce Glaucoma Risk

How To Stop Hot Flashes Fast: 7 Cooling Tricks Doctors Say Work in Seconds