Progesterone

About Progesterone

Progesterone readies and stabilizes the womb lining. The capsules, micronized progesterone in peanut oil, prevent overgrowth of the lining in postmenopausal women with a uterus who take conjugated estrogens, as 200 mg at bedtime for 12 days of each 28-day cycle, and bring on a period in secondary amenorrhea, as 400 mg at bedtime for 10 days. Bedtime dosing is because they can cause marked drowsiness and dizziness, and anyone allergic to peanuts must not take them.

The capsule label revised in February 2026 no longer carries a boxed warning. It used to open with one citing the Women’s Health Initiative findings of more blood clots, stroke, heart attack, breast cancer and probable dementia with estrogen plus progestin therapy; that month the FDA approved removing the statements on cardiovascular disease, breast cancer and dementia from the boxed warnings of menopausal hormone therapy products, and the Prometrium label now carries those findings in its warnings section instead. The capsules are not used with undiagnosed genital bleeding, breast cancer, blood clots or liver disease; headache, breast tenderness, joint pain and low mood are common.

The vaginal products are for assisted reproduction. Crinone 8 percent gel, 90 mg per single-use applicator, is used once or twice a day after egg retrieval for up to 10 to 12 weeks if pregnancy occurs; the 4 percent strength has been discontinued. Endometrin is a 100 mg insert placed two or three times a day for up to 10 weeks; its label says efficacy in women 35 and older has not been clearly established. The injection, 50 mg per mL in sesame oil, is given into a muscle for amenorrhea and abnormal uterine bleeding from hormonal imbalance; anyone allergic to sesame should not have it.

Taking Progesterone

How to take it

Capsules: swallow whole at bedtime with water, on the days of the cycle your prescriber sets. Gel: one applicator into the vagina once or twice a day. Inserts: one insert with the applicator two or three times a day. Injection: into a muscle, by a clinician or as you were taught.

If you miss a dose

Use the missed dose as soon as you remember, unless it is almost time for the next; then skip it and continue your regular schedule. Do not double a dose.

Storage

All forms at room temperature, away from excess heat and moisture, out of reach of children; keep capsules in the original container.

Interactions to know about

Ketoconazole and other strong CYP3A4 inhibitors can raise progesterone levels, and inducers such as rifampin, carbamazepine and St. John’s wort can lower them. Do not use the gel or inserts with other vaginal products; the Crinone label asks for a gap of at least 6 hours. Report leg pain or swelling, chest pain, sudden breathlessness or vision changes at once.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Progesterone differs from pharmacy to pharmacy

Generic capsules cost pharmacies little and a 12-day course each month is a small fill, so quotes mostly reflect the dispensing fee; a prescription for Prometrium by name without substitution is quoted at a brand price. The fertility products are where cash prices climb: Crinone has one maker and no generic, so quotes differ by markup alone, and although Endometrin now has generic competitors, a fertility prescription usually names one product.

Ways to pay less for Progesterone without insurance

• Ask for the prescription to be written generically, or to allow substitution, for capsules and vaginal inserts alike.
• If vaginal progesterone is prescribed, ask the fertility clinic whether a generic insert would suit you as well as Crinone or Endometrin.
• For the injection, ask whether the pharmacy stocks the vial and what it charges for syringes and needles.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Progesterone

1. 1.Does this capsule contain peanut oil?
2. 2.Why is it taken at bedtime?
3. 3.How long should I wait between a vaginal dose and another vaginal product?
4. 4.How do I use the gel applicator or the insert?
5. 5.Does it interact with my antifungal or seizure medicines?

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