What Is Progesterone?

Progesterone is a naturally occurring steroid hormone that plays a central role in the female reproductive system. Your body produces Progesterone primarily in the ovaries after ovulation, and it's essential for regulating your menstrual cycle, preparing the uterus for pregnancy, and maintaining early pregnancy.

When we talk about Progesterone as a medication, we're usually referring to bioidentical Progesterone — a lab-made version that is chemically identical to the hormone your body produces naturally. It belongs to a class of drugs called progestins (or progestogens).

Progesterone is available under several brand names, including:

• Prometrium — oral capsules (100 mg, 200 mg)
• Crinone — vaginal gel (4%, 8%)
• Endometrin — vaginal inserts (100 mg)
• Generic Progesterone — oral capsules, injectable, and compounded forms

What Is Progesterone Used For?

Progesterone is FDA-approved for several conditions and is also used off-label for others. Here are the main uses:

FDA-Approved Uses

• Prevention of endometrial hyperplasia: Postmenopausal women taking estrogen need Progesterone to protect the uterine lining from overgrowth, which can lead to cancer. This is the most common reason Progesterone is prescribed.
• Secondary amenorrhea: When a woman who previously had normal periods stops menstruating for reasons other than pregnancy or menopause, Progesterone can restart the menstrual cycle.
• Fertility support (ART): Vaginal Progesterone (Endometrin, Crinone) is used to support embryo implantation and early pregnancy during IVF and other assisted reproductive technology cycles.

Common Off-Label Uses

• Luteal phase support in IVF: Supplementing Progesterone during the period after embryo transfer
• Prevention of preterm birth: Vaginal Progesterone may help women with a short cervix reduce the risk of delivering too early
• Irregular uterine bleeding: Progesterone can help regulate abnormal bleeding patterns
• Premenstrual syndrome (PMS): Some providers prescribe Progesterone for severe PMS symptoms

To understand more about how Progesterone produces these effects, read our guide on how Progesterone works.

Progesterone Dosage Forms and Strengths

Progesterone comes in several formulations, and the right one for you depends on your condition and your doctor's recommendation:

Oral Capsules (Prometrium and Generics)

• Strengths: 100 mg and 200 mg
• For endometrial hyperplasia prevention: 200 mg daily at bedtime for 12 days of each 28-day cycle
• For secondary amenorrhea: 400 mg daily at bedtime for 10 days

Vaginal Gel (Crinone)

• Strengths: 4% (45 mg) and 8% (90 mg)
• Administered with a pre-filled applicator every other day or daily depending on the indication

Vaginal Inserts (Endometrin)

• Strength: 100 mg
• Typically used: Two to three times daily for fertility support

Intramuscular Injection

• Strength: 50 mg/mL (Progesterone in oil)
• Dose range: 25-100 mg daily, administered by a healthcare provider or self-injected

Compounded Formulations

• Vaginal suppositories and creams prepared by compounding pharmacies in custom doses

How to Take Progesterone

How you take Progesterone depends on the form prescribed:

Oral capsules: Take at bedtime on an empty stomach with a glass of water. Taking it at bedtime is important because oral Progesterone causes drowsiness — this way, the sedative effect actually helps you sleep. Do not take with food, as food increases absorption and may increase side effects.

Vaginal gel: Use the pre-filled applicator provided. Insert the applicator into the vagina and squeeze to release the gel. Use at the same time each day for consistent hormone levels.

Vaginal inserts: Insert directly into the vagina using the applicator provided. Follow your doctor's instructions for timing and frequency.

Injection: Given as an intramuscular injection into the buttock. Your healthcare provider will teach you the technique if you need to self-administer at home.

Important Safety Information

Boxed Warning

Progesterone carries an FDA boxed warning when used with estrogen for menopausal hormone therapy. The key points are:

• Increased risk of heart attack, stroke, and blood clots
• Increased risk of breast cancer with prolonged use
• Should not be used to prevent heart disease or dementia
• Use the lowest effective dose for the shortest time needed

Who Should NOT Take Progesterone

Progesterone is contraindicated in patients with:

• Known or suspected breast cancer or other hormone-sensitive cancers
• Undiagnosed abnormal vaginal bleeding
• Active or history of blood clots (DVT, PE)
• Active or recent stroke or heart attack
• Liver disease or dysfunction
• Allergy to Progesterone or peanuts (Prometrium contains peanut oil)
• Known or suspected pregnancy (oral form only — vaginal forms are used in pregnancy)

Drug Interactions

Progesterone interacts with several medications. Key interactions include:

• CYP3A4 inhibitors (Ketoconazole, Clarithromycin) — may increase Progesterone levels
• CYP3A4 inducers (Rifampin, Carbamazepine, St. John's Wort) — may decrease Progesterone levels
• Anticoagulants (Warfarin) — Progesterone may alter blood clotting

For a complete list, see our guide on Progesterone drug interactions.

How Much Does Progesterone Cost?

The cost of Progesterone varies significantly by formulation:

• Generic oral capsules: $14-$30 for 30 capsules with a coupon (about $79 retail)
• Brand Prometrium: $200-$422 for 30-90 capsules
• Crinone vaginal gel (8%): $200-$350 per box
• Endometrin vaginal inserts: $300-$600 per cycle

Generic oral Progesterone is widely available and affordable with discount coupons from GoodRx or SingleCare. Most commercial insurance plans and Medicare Part D cover generic Progesterone on Tier 1 or Tier 2 formulary. For more savings strategies, read our guide on how to save money on Progesterone.

Current Availability (2026)

Progesterone is currently experiencing an active shortage across multiple formulations. Capsules, injections, and vaginal inserts are all listed on ASHP's shortage list. If you're having trouble finding Progesterone, MedFinder can help you check pharmacy stock near you.

The Bottom Line

Progesterone is a versatile, naturally occurring hormone used to treat a wide range of conditions — from menopausal hormone therapy to fertility support to menstrual irregularities. It comes in multiple formulations, is generally well-tolerated (read about side effects here), and is affordable in generic form. The biggest challenge in 2026 is finding it in stock, but tools like MedFinder can help.