Hormone replacement therapy (HRT) supplements hormones to ease the most disruptive menopause symptoms like hot flashes, night sweats, and vaginal dryness. But if you have a uterus, estrogen alone isn’t as safe in the long term. You need to pair it with progestin or progesterone to prevent endometrial cancer. 

Prometrium® and Provera® are both medications that deliver progestogen. In this guide, discover how they work, the difference between them, and which is best for your goals. 

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Prometrium® vs. Provera®: Key differences

Prometrium® and Provera® are both progestogens, a category of drugs that includes natural progesterone and lab-made versions designed to work like it. If you still have your uterus and start HRT, your doctor will prescribe a progestogen alongside estrogen to prevent the uterine lining from overgrowing. 

Prometrium® contains micronized progesterone. This is the same molecule your ovaries produce during your menstrual cycle, sourced from plants and ground into tiny particles so your body can absorb it. Because it’s molecularly identical to your body’s own hormone, it’s sometimes called bioidentical or body-identical progesterone. 

Provera®’s active ingredient is the progestin medroxyprogesterone acetate (MPA). Progestins are lab-made molecules designed to trigger the same receptors as progesterone. MPA achieves the main goal of keeping the uterine lining in check, but its structure doesn’t match natural progesterone’s exactly. Because of this structural difference, MPA also interacts with other hormone receptors, creating different side effects and risk profiles.

Here’s how the two compare:

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Who should use Prometrium® or Provera®?

Both Prometrium® and Provera® get prescribed to protect the uterine lining during HRT, restart periods that have gone missing, and, in Provera®’s case, manage abnormal uterine bleeding caused by hormonal imbalance. Your provider will recommend one based on your health history and priorities.

Who may be a better fit for Prometrium®

The benefits of Prometrium® stand out for certain health profiles. It may be a better fit if:

• You have diabetes, obesity, or a smoking history. The same recommendation applies if you have dense breast tissue or blood clot risk factors.
• Breast cancer is a concern. A 2016 meta-analysis found that women using micronized progesterone had a 33% lower breast cancer risk compared to those using synthetic progestins. This evidence is observational, not from a controlled trial, but it’s consistent across multiple large studies.
• You struggle with sleep. Your body breaks down Prometrium® into allopregnanolone, a brain chemical that enhances GABA activity. This calms your nervous system.

Who may be a better fit for Provera®

What’s Provera® used for? It may be better for you if:

• You have a peanut allergy. Prometrium® capsules contain peanut oil, and Provera®’s don’t.
• You need treatment for abnormal uterine bleeding. MPA helps the uterine lining mature and shed in a more organized cycle, and Provera® has a specific FDA approval for this use.
• Prometrium’s sedative effect is a problem for you. The calming effects that help some women can cause excessive dizziness or drowsiness in others, even with bedtime dosing.
• Cost or insurance is a deciding factor. MPA has been available since 1959, so more manufacturers produce it, and more insurance formularies list it as a preferred option. Micronized progesterone has been in the market since 1998, and generic versions also exist, but out-of-pocket costs may be higher.

Safety and risks of Prometrium® vs. Provera®

Because Prometrium® and Provera® interact with your hormone receptors differently, their side effects also differ.

Prometrium® side effects

The five most common side effects in Prometrium®’s trial were: 

• Breast tenderness 
• Depression
• Dizziness
• Abdominal bloating 
• Vaginal discharge 

Prometrium® can also cause drowsiness, so its label instructs you to take it at bedtime.

Provera® side effects

Provera®’s most commonly reported side effects were:

• Breakthrough bleeding and spotting
• Breast tenderness
• Headache
• Dizziness
• Mood changes (including depression and nervousness)
• Insomnia
• Weight changes
• Nausea 

Boxed warning

Provera®’s label contains a boxed warning for cardiovascular disorders, breast cancer, and probable dementia. 

This comes from the 2002 Women’s Health Initiative (WHI). This study tested MPA (Provera®’s active ingredient) combined with estrogen in over 16,000 women. In one year, for every 10,000 women, the group taking this combination saw:

• 26 blood clots compared to 13 on placebo
• 18 clots reaching the lungs compared to eight
• 33 strokes compared to 25
• 41 breast cancer diagnoses compared to 33

Prometrium® used to share these boxed warnings with Provera®, but the FDA removed them in November 2025. 

When to call your provider

Contact your provider right away if you notice any of these warning signals while taking either medication:

• Chest pain
• Shortness of breath
• Sudden severe headache
• Weakness or numbness on one side of your body
• Vision changes
• Leg pain, swelling, or warmth

These can signal a blood clot, stroke, or other serious event. Before starting either Prometrium® or Provera®, review all your current medications with your provider to check for possible interactions.

Cost and access of Prometrium® vs. Provera®

Both Prometrium® and Provera® require a prescription and are available at standard U.S. pharmacies. Generic versions exist for both. Because MPA has been in the market for longer, its generics tend to cost less.

It’s important you know that out-of-pocket costs vary depending on the dose, whether you use brand or generic, and your insurance plan. If your plan doesn’t cover micronized progesterone or places it on a higher copay tier, but there’s a clinical reason to prefer it, your provider can request authorization.

How to choose between Prometrium® and Provera®

The best progestogen choice for you depends on your symptoms, health history, and priorities. 

If you’re reviewing your HRT plan and want to understand whether Prometrium® or Provera® is the right fit, reach out to Maven Clinic. We connect you with specialists who build an action plan that works for your body and lifestyle. Learn more today.