What time of day should I take progesterone?

Optimal Timing for Taking Progesterone

For optimal therapeutic effect and minimal side effects, progesterone should be taken at bedtime regardless of formulation type.

Oral Progesterone Administration

• Oral progesterone capsules should be taken as a single daily dose at bedtime to minimize side effects like drowsiness and dizziness 1
• For prevention of endometrial hyperplasia in postmenopausal women using estrogen therapy, the recommended dose is 200 mg orally at bedtime for 12 continuous days per 28-day cycle 1
• For treatment of secondary amenorrhea, the recommended dose is 400 mg orally at bedtime for 10 days 1
• Taking progesterone at bedtime minimizes the impact of drowsiness, which is the most common side effect 2

Rationale for Bedtime Administration

• Oral micronized progesterone causes mild and transient drowsiness, making bedtime administration ideal 2
• Some women experience extreme dizziness and drowsiness during initial therapy, which can include blurred vision, difficulty speaking, difficulty walking, and feeling abnormal 1
• Taking progesterone while standing with a glass of water is recommended for women who have difficulty swallowing the capsules 1

Pharmacokinetics Supporting Bedtime Dosing

• Peak plasma concentrations of oral progesterone occur approximately 2 hours after ingestion 3
• The metabolite 20 alpha-dihydroprogesterone remains elevated for at least 12 hours after administration, providing sustained progestational effects 3
• Evening administration of higher doses (200 mg at 9:00 PM vs 100 mg at 9:00 AM) results in higher sustained plasma levels 3

Different Progesterone Formulations

• Vaginal progesterone formulations (gels, suppositories) are typically administered once or twice daily depending on the indication 4
• For prevention of preterm birth in women with short cervical length, vaginal progesterone (90-mg gel or 200-mg suppository) is administered daily from diagnosis until 36 weeks 5
• For hormone replacement therapy, vaginal progesterone may be administered at bedtime for 12-14 days every 28 days 5

Cautions and Considerations

• Use caution when driving a motor vehicle or operating machinery after taking progesterone due to potential dizziness or drowsiness 1
• Progesterone metabolites, particularly those reduced at the 5-alpha position, can cause significant drowsiness that may impair the ability to operate a vehicle 4
• If severe symptoms occur (blurred vision, difficulty speaking, difficulty walking), discuss with your healthcare provider immediately 1

Special Populations

• For women using progesterone to prevent preterm birth, administration schedules depend on the specific formulation:
  • 17-alpha-hydroxyprogesterone caproate (17P) is administered as 250 mg IM weekly from 16-20 weeks until 36 weeks 5
  • Vaginal progesterone is administered daily as either 90-mg gel or 200-mg suppository 5

Remember that bedtime administration is strongly recommended for oral progesterone to minimize side effects while maintaining therapeutic efficacy 1, 2.