Progesterone

Progesterone is a naturally occurring female hormone that plays a central role in regulating ovulation, menstruation, and pregnancy. It is produced mainly by the ovaries (corpus luteum), placenta, and adrenal glands. Manufactured (synthetic) progesterone is bioidentical, meaning it shares the same molecular structure as the hormone your body makes naturally.

Progesterone is available in multiple forms: oral capsules, vaginal gel, vaginal inserts, and an injection.

It first received FDA approval on November 1, 1974.

Progesterone is prescribed for several conditions, including:

• Absent or irregular periods (amenorrhea): To trigger menstrual periods in women who are not yet menopausal but are not menstruating due to low progesterone levels.
• Hormone replacement therapy (HRT): To protect the uterine lining in women taking estrogen who have not had a hysterectomy.
• Fertility treatment: To support embryo implantation and sustain early pregnancy as part of assisted reproductive technology (ART).

Always follow your doctor's instructions and prescription label exactly.

Progesterone Capsules (Oral)

• Take with a full glass of water, preferably at bedtime, to minimize dizziness.
• May be prescribed for short cycles (10–12 days per menstrual cycle).
• Perform monthly breast self-exams and schedule regular physical exams.
• Alert any surgeon or treating physician that you are taking progesterone before any procedure.

Progesterone Vaginal Insert

• Used to support embryo implantation in ART fertility programs for women under 35 years of age.
• Typical dose: one insert placed vaginally 2–3 times daily for up to 10 weeks.
• Use the disposable applicator provided. Do not use other vaginal products concurrently.

Progesterone Vaginal Gel

• 8% gel: Used for progesterone supplementation or replacement in ART. Dose: 90 mg once daily (or twice daily for ovarian failure). If pregnancy occurs, may continue up to 10–12 weeks.
• 4% gel: Used for secondary amenorrhea. Apply vaginally every other day for up to 6 doses. If no response, switch to 8% gel.
• Important: Increasing the gel volume does not increase absorption. Use the higher-concentration gel to increase dosage.

Progesterone Injection

Administered intramuscularly by a healthcare provider.

• Amenorrhea: 5–10 mg daily for 6–8 consecutive days; withdrawal bleeding expected 48–72 hours after the last injection.
• Functional uterine bleeding: 5–10 mg daily for 6 doses; bleeding should stop within 6 days.
• With estrogen therapy: Begin progesterone after 2 weeks of estrogen. Discontinue if menstrual flow begins during progesterone therapy.

Serious Risks of Progesterone

Using progesterone may increase your risk of blood clots, stroke, heart attack, and certain cancers. Tell your healthcare provider about all medical conditions before starting treatment, especially if you have:

• Heart disease, circulation problems, have had a stroke, or a heart attack
• Kidney disease
• Asthma
• Seizures or epilepsy
• Diabetes
• Migraines
• Lupus
• High calcium levels in the blood
• Endometriosis
• Thyroid problems
• A history of depression.

Fluid retention: Progesterone may cause fluid retention. If you have heart failure or kidney disease, discuss this risk with your provider before use.

Drowsiness and dizziness: Progesterone capsules can cause transient dizziness or drowsiness. Take them at bedtime and use caution when driving or operating machinery.

Breastfeeding: Progesterone passes into breast milk and may harm a nursing baby. Talk to your doctor before use if you are breastfeeding.

Cancer risk: Progesterone treatment may increase your risk of certain types of cancers, including cancer of the breast or uterus. If you have or have had cancer, talk with your healthcare provider about whether you should take progesterone.

Do not use or take progesterone if you:

• Are allergic to progesterone or any inactive ingredients in your formulation
• Are allergic to peanuts (if prescribed Prometrium capsules, which contain peanut oil) or sesame oil/seeds (if prescribed the injection)
• Have unexplained or abnormal vaginal bleeding
• Have or have had certain cancers (including breast or uterine cancer)
• Have had a stroke, heart attack, or blood clot
• Have liver disease or liver problems
• Have a known missed abortion, ectopic pregnancy, or a recent miscarriage where tissue may still be in the uterus.

Do not use progesterone if you are pregnant, unless directed by your doctor for fertility support.

Serious Side Effects

Get emergency medical help if you have signs of an allergic reaction after taking or using progesterone, such as hives, difficulty breathing, or swelling of your face, lips, tongue, or throat.

Progesterone may cause serious side effects. Call your doctor at once if you have:

• Unusual vaginal bleeding
• Pain or burning when you urinate
• A breast lump
• Sudden vision problems, severe headache, or pain behind your eyes
• Symptoms of depression (sleep problems, weakness, mood changes)
• Severe dizziness or drowsiness, spinning sensation, confusion, shortness of breath
• Heart attack symptoms, such as chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating
• Liver problems, such as nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)
• Signs of a stroke, including sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with speech or balance
• Signs of a blood clot in the lung, such as chest pain, sudden cough, wheezing, rapid breathing, coughing up blood, or
• Signs of a blood clot in your leg, such as pain, swelling, warmth, or redness in one or both legs.

Common Side Effects

The most common side effects of progesterone are:

• Drowsiness or dizziness
• Breast pain
• Mood changes
• Headache
• Constipation or diarrhea
• Heartburn
• Bloating or swelling in your hands or feet
• Joint pain
• Hot flashes or
• Vaginal discharge.

Side Effects Specific to Vaginal Inserts (Fertility Use)

• Pelvic pain, abdominal cramping, or bloating
• Nausea or vomiting
• Ovarian hyperstimulation syndrome (swollen ovaries)
• Urinary tract infections
• Vaginal irritation, burning, or discharge
• Fatigue and vaginal bleeding.

Note:

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

• Capsules: Take as soon as you remember. Skip if your next dose is near. Do not double up. Call your doctor if you miss more than one dose.
• Vaginal insert/gel: Take the missed dose as soon as you remember, but do not exceed your total daily dose.
• Injection: Call your healthcare provider to reschedule.

In case of overdose, seek emergency medical attention or call Poison Control at 1-800-222-1222.

Progesterone capsules may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Do not use any other vaginal products when you are using the progesterone vaginal insert.

There may be other drugs that can interact with progesterone. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

The results of some laboratory tests, such as coagulation tests and thyroid function tests, may be altered with the use of estrogen plus progesterone therapy.