From the Guidelines
The dose of micronized progesterone for prevention of preterm birth is 200 mg vaginally once daily, as recommended by recent guidelines. This dose is based on the most recent and highest quality study available, which suggests that vaginal progesterone reduces the risk of preterm birth and perinatal morbidity and mortality in women with a short cervix 1. The study found that vaginal progesterone treatment was associated with a reduction in preterm birth at <32 weeks of gestation and a decrease in composite neonatal morbidity and mortality.
For other conditions, such as hormone replacement therapy in postmenopausal women, the typical dose is 100-200 mg daily taken orally at bedtime. For luteal phase support in assisted reproductive technology, 600-800 mg daily is commonly used, often divided into three doses and administered vaginally. For secondary amenorrhea, 400 mg daily is often prescribed. However, for prevention of preterm birth, the recommended dose is 200 mg vaginally once daily.
It's worth noting that the American College of Obstetricians and Gynecologists has recommended vaginal progesterone as a management option for pregnant individuals with a short cervix, and the most studied formulations of vaginal progesterone are 90-mg (8%) progesterone gel and 200-mg micronized progesterone capsules 1. Vaginal administration provides higher local concentrations in the uterus with fewer systemic side effects, and micronized progesterone is preferred over synthetic progestins because it's identical to the body's natural hormone and may have fewer side effects.
Some key points to consider when prescribing micronized progesterone include:
- The dose and formulation may vary depending on the condition being treated
- Vaginal administration is preferred for prevention of preterm birth
- Micronized progesterone is preferred over synthetic progestins
- Patients should be aware of potential side effects, such as drowsiness with oral administration, and that oral capsules contain peanut oil, so those with peanut allergies should avoid this formulation.
From the FDA Drug Label
The usual dose of micronized progesterone is not explicitly stated in the provided drug labels, but the USUAL DOSE is mentioned to be found in the package insert. TABLE 1 summarizes the mean pharmacokinetic parameters in postmenopausal women after five oral daily doses of progesterone capsules 100 mg, 200 mg, and 300 mg as a micronized soft-gelatin capsule formulation.
- The doses mentioned are:
- 100 mg
- 200 mg
- 300 mg Although the exact usual dose is not provided, the doses of 100 mg, 200 mg, and 300 mg are mentioned in the context of the pharmacokinetic study 2.
From the Research
Dose of Micronized Progesterone
- The dose of micronized progesterone is 400 mg twice daily, as studied in the PROMISE and PRISM trials 3, 4.
- This dose was associated with increasing live birth rates according to the number of previous miscarriages, particularly in women with a history of 3 or more previous miscarriages and current pregnancy bleeding 3, 4.
- The use of vaginal micronized progesterone 400 mg twice daily may benefit women with a history of miscarriage who present with bleeding in early pregnancy 3, 4.
Comparison with Other Studies
- Other studies have evaluated the use of micronized progesterone in different contexts, such as hormone replacement therapy 5, 6 and treatment of secondary amenorrhea and premenopausal bleeding disorders 7.
- These studies have reported various doses of micronized progesterone, including 200 mg 6 and doses approved for treatment of secondary amenorrhea and postmenopausal hormone replacement therapy 7.
- However, the specific dose of 400 mg twice daily is primarily associated with the prevention of miscarriage in women with early pregnancy bleeding 3, 4.