Menopause hormone therapy is commonly used to treat symptoms like hot flashes and vaginal dryness. As estrogen levels drop during perimenopause and menopause, progesterone levels also change and may play a role in these symptoms.

To better understand progesterone and its role in hormone therapy for menopause, we spoke with Maariya Bassa, a board-certified nurse-midwife and women’s health nurse practitioner at Unity Healthcare in Washington, D.C.

What Is Progesterone?

Progesterone is a hormone produced by a temporary structure in the ovaries called the corpus luteum. This structure forms for a short time after ovulation (when the ovary releases an egg).

Natural progesterone plays some important roles in the reproductive system. Its main job is to thicken the endometrium (the lining of the uterus) to prepare for a possible pregnancy. If pregnancy occurs, the corpus luteum stays active and keeps making progesterone to support the pregnancy. Once the placenta forms, it takes over progesterone production for the rest of the pregnancy.

If pregnancy does not occur, the body sheds the thickened endometrium, and the corpus luteum breaks down. This process leads to a menstrual period.

Progesterone’s Role in Hormone Therapy

Progesterone plays a twofold role in menopause hormone therapy (also called hormone replacement therapy, or HRT). “One, it’s used as protection for the endometrium,” Bassa said. “Progesterones have also been shown to help improve sleep, which can help improve mental clarity.”

Estrogen-Only Hormone Therapy vs. Combined Hormone Therapy

Progesterone is rarely used alone in menopause hormone therapy. The two main types are estrogen-only hormone therapy and combined hormone therapy, which includes both estrogen and progestin (a lab-made form of progesterone that works in a similar way in the body).

Combination hormone therapy is typically recommended for women who still have a uterus. Those who’ve had a hysterectomy may use estrogen-only hormone therapy. However, some people without a uterus may still choose combined therapy for added benefits, such as better sleep or mood support.

Estrogen-only hormone therapy can cause complications if someone still has a uterus and endometrium. “If you just give someone straight estrogen and they have a uterus,” Bassa said, “they can develop endometrial hyperplasia or endometrial cancer.” Endometrial hyperplasia means the uterine lining becomes too thick.

Benefits and Possible Drawbacks of Progesterone

In addition to supporting the endometrium, hormone therapy with progesterone may offer significant quality-of-life benefits, such as supporting sleep and bone health.

Improved Sleep

According to Bassa, progesterone in hormone therapy for menopause may help improve sleep and brain fog. “That does have a big benefit regardless of whether or not the patient needs it for endometrial protection,” she said. This can be especially helpful for women who experience insomnia (trouble sleeping) during perimenopause.

Sleep problems in perimenopause and menopause are common. They may be caused by nighttime hot flashes, anxiety, sleep disorders like sleep apnea, or changes in brain activity linked to menopause. Some research suggests that progestin used in hormone therapy may also help reduce hot flashes.

Bone Health

“We are finding more and more that menopause hormonal therapies are having a positive impact on osteoporosis,” Bassa said. A recent study found that estrogen-progesterone hormone therapy may be more effective than estrogen-only therapy at preserving bone mineral density (a measure of bone strength).

Other Potential Health Benefits

Bassa also described the broader benefits of menopause hormone therapy: “We are finding more and more that menopause hormonal therapies are having a positive impact on osteoporosis, on heart health, on cognitive function — not just thinking about menopause treatment as treatment for hot flashes or treatment for vaginal atrophy, but also some more of the systemic benefits that it can have on your bones, your heart, your brain.”

Possible Drawbacks of Progesterone Hormone Therapy for Menopause

Bassa also discussed possible drawbacks of taking progesterone for menopause.

Mood Impact

“Some folks have difficulty tolerating progesterone because of the adverse effects it can have on mood,” Bassa said. Although this isn’t a common side effect, some women may be more susceptible to these effects.

Mixed Evidence on Cognitive Health

Many recent studies have explored the link between menopause hormone therapy and dementia risk, with mixed results. Some studies suggest it may be protective, others suggest it may increase risk, and some show no clear difference. Differences in study design and the people included in the studies may help explain these mixed findings.

It’s important to consider the full body of research and not focus on a single study. That said, some research suggests that estrogen-only hormone therapy may reduce dementia risk, while combined estrogen-progesterone therapy may not have the same effect.

Your Options for Progesterone Hormone Therapy

Combination hormone therapy that includes progesterone comes in several forms. You can work with your healthcare provider to figure out what’s best for you.

Oral Therapy

Oral hormone therapy comes as tablets or pills taken by mouth. These are a type of systemic hormone therapy, meaning they affect the whole body. This is different from local hormone therapy, which is applied to specific targeted areas like vaginal tissues.

Some hormone therapy pills contain both estrogen and progestin and are taken every day, which is called continuous-combined hormone therapy. Estrogen and progesterone can also be taken separately, such as using an estrogen patch along with a progesterone pill.

Another option, called cyclic therapy, involves taking daily estrogen and adding progestin pills for 10 to 14 days each month. Your healthcare provider can help you decide which approach is right for you.

Transdermal Options

Transdermal hormone therapy is given through the skin, such as with a patch or topical cream. Some patches contain both estrogen and progestin, but this method is most often used for estrogen. One benefit of transdermal estrogen is that it has less effect on the liver than oral estrogen. “[An oral pill] has more of an impact on your liver,” Bassa said. “A transdermal patch doesn’t necessarily have those risks.”

Progesterone is usually taken by mouth, most often as micronized progesterone. Although progesterone can be made into creams, these aren’t typically first-line treatments and may not be absorbed as reliably.

It’s important to use transdermal hormone therapy carefully, as the hormones can transfer to others through skin contact. “If animals or children are touching those areas, the [hormones] on the skin can actually be passed to other people or even your animals,” Bassa said. “These other mammals can also start to develop some of those symptoms of the increased [hormones].”

Bassa noted that insurance providers may be less likely to cover transdermal options. “Unfortunately, some costs are associated with transdermal options,” she said. “If insurance doesn’t cover it and the patient has no risk factors for why they couldn’t take an oral tablet, then that would lead us to prescribe the oral tablet.”

Intrauterine Devices

Intrauterine devices (IUDs) that release progestin can be used as part of menopause hormone therapy to protect the uterine lining and help control bleeding. However, they don’t treat other menopause symptoms. A healthcare provider inserts the device into the uterus, where it steadily releases hormones.

IUDs are mainly used for birth control. “I think for perimenopause, my biggest tip is that you still need contraception if you are sexually active,” Bassa said.

Talk to Your Healthcare Provider

Bassa emphasized the importance of individualized care during menopause and perimenopause: “Menopause treatment is so tailored to individual symptoms, and it is so much of a conversation between the clinician and the patient about the symptoms that we’re actually looking to treat as opposed to, well, this is just standard treatment.”

If your perimenopause symptoms affect your quality of life, consider talking with your doctor about your hormone therapy options. They can help you choose an approach that fits your symptoms, goals, and risk factors.