Can Progesterone Cream Protect Your Uterus Like Prometrium?

Over-the-counter progesterone cream has not been shown to protect the uterus the way oral Prometrium does. In studies of postmenopausal women using estrogen, the cream did not reliably keep the uterine lining from overgrowing, and an expert panel concluded transdermal progesterone does not provide that protection. Oral micronized progesterone, taken as 200 mg at bedtime for 12 days of each 28-day cycle, cut the rate of lining overgrowth to 6%, compared with 64% on estrogen alone, in a three-year trial.

Why do you need progesterone with estrogen if you still have a uterus?

If you still have a uterus, estrogen therapy needs a progestogen alongside it to protect against uterine cancer, according to The Menopause Society. If you've had a hysterectomy, you can usually take estrogen alone.

Estrogen on its own makes the lining of the uterus (the endometrium) grow. Left unchecked, that growth can become hyperplasia, an overgrowth of the lining that can lead to cancer. In the Prometrium label trial, 358 postmenopausal women with an intact uterus were followed for 36 months. Among the women taking estrogen alone, 64% developed hyperplasia.

Progesterone is your uterus's safety net. Whatever form you choose has to show that it keeps the lining in check, not only that some hormone gets into your body.

What happened when women used progesterone cream with estrogen?

Here is what the cream studies and the Prometrium trial found. None of the studies compared cream and Prometrium directly, but the results point the same way.

Don't saliva tests show progesterone cream gets absorbed?

Cream fans often point to high saliva readings as proof that the cream works. In the cream trial that measured saliva, the levels varied so much that the researchers called them completely unreliable for judging what the hormone was doing in the body.

Menopause experts say there is no scientific basis for using saliva tests to adjust hormone doses. They also say that how much progesterone cream gets through the skin is variable and unpredictable. Some compounding pharmacies and self-proclaimed experts claim the cream prevents estrogen-driven overgrowth of the lining, but topical progesterone cream has not been shown to do that.

The Menopause Society warns that custom-compounded hormones may not contain the prescribed amounts, and that when your progesterone level is too low, you are not protected against uterine cancer. A product that may not deliver a predictable dose shouldn't be trusted with that job.

What is it like to take Prometrium?

If you liked the cream because it felt natural, the pill gives you that too. According to the Prometrium label, the progesterone in Prometrium is made from a plant source and is chemically identical to the progesterone your ovaries make. It's the bioidentical hormone you wanted, in a capsule with trial data behind it.

For uterine protection, the label dose is 200 mg once a day at bedtime for 12 days in a row of each 28-day cycle. You take it at night because some women get very drowsy or dizzy. The capsules contain peanut oil, so tell your clinical team about any peanut allergy.

The drowsiness has an upside. Oral micronized progesterone breaks down into calming byproducts that reach the brain, and these can improve sleep, especially after menopause. It can also cause sedation, dizziness, tiredness, mood changes and nausea.

One woman on r/Menopause took 100 mg with dinner and described an "absolutely hammered feeling that I loooooove" followed by a "blissful 9 hours of sleep." She wrote that she "couldn't sleep for 16 flippin years through peri." That was her dose and her experience, and it differs from the label's 200 mg bedtime dose for uterine protection.

The label says Prometrium is not for women who have or have had a blood clot, stroke or heart attack, or who have breast cancer or a history of it. Your clinical team asks about your history before your plan is set.

What if oral progesterone doesn't agree with you?

You still have options, and cream isn't one of them. The Menopause Society says side effects from hormone therapy can often be eased by lowering the dose or switching forms, and finding the right dose and routine can take some trial and error.

Vaginal micronized progesterone is the main alternative. The expert panel said it may protect the lining at 45 mg a day for at least 10 days a month, or at 100 mg every other day, for up to 3 to 5 years. Both uses are off-label.

The evidence for the vaginal form is thinner. In the ELITE trial, women used 45 mg of vaginal progesterone a day for 10 days each month. Hyperplasia occurred in 12.7% of them, compared with 3.1% on placebo, and there were two cases of endometrial cancer. That result suggests this dose may not be enough.

One woman on r/Menopause worries about this trade-off too. She wrote: "I'm also nervous about trying progesterone vaginally because I'm worried it won't protect my uterus enough." Bring that worry to your clinical team instead of switching to cream. They can weigh the forms and doses against your history and how your body reacts.

If you want estrogen for hot flashes, sleep or feeling like yourself again, take the quiz. Our clinical team can prescribe bioidentical estrogen if it fits your goal, and will look at whether you still have a uterus and what protection your plan needs.