Progesterone 500mg is a high-dose, micronized, oral formulation of the natural female sex hormone, progesterone. It is a progestogen used primarily in hormone replacement therapy (HRT) and for the treatment of secondary amenorrhea. The micronization process enhances its oral bioavailability by improving dissolution and absorption. In the Indian context, it is a critical component of assisted reproductive technology (ART) protocols and is widely used in gynecological endocrinology.
Adult: Secondary Amenorrhea: 400 mg daily at bedtime for 10 days. HRT (Sequential): 200 mg daily for the last 12-14 days of each estrogen cycle. Luteal Phase Support (ART): 400-600 mg daily in divided doses, starting after oocyte retrieval and continuing for up to 10-12 weeks of pregnancy.
Note: Take orally, preferably at bedtime to minimize dizziness and drowsiness. Can be taken with or without food, but taking with food may improve tolerance. Swallow the soft gelatin capsule whole with a full glass of water. Do not crush or chew.
Progesterone binds to and activates the intracellular progesterone receptor (PR), a nuclear hormone receptor. The hormone-receptor complex translocates to the nucleus, binds to specific progesterone response elements (PREs) on DNA, and modulates the transcription of target genes. This results in the transformation of the estrogen-primed proliferative endometrium into a secretory one, inhibition of gonadotropin secretion (LH surge), and maintenance of pregnancy.
Pregnancy: US FDA Category B. Progesterone is used extensively to support pregnancy in ART. It is considered safe when used as indicated. However, it should not be used to prevent habitual abortion without confirmation of progesterone deficiency.
Driving: May cause significant drowsiness and dizziness. Patients should be cautioned against driving or operating heavy machinery, especially when initiating therapy or taking the dose during daytime.
| Ketoconazole, Itraconazole, Fluconazole | Increased progesterone levels due to CYP3A4 inhibition. Risk of enhanced side effects. | Major |
| Rifampicin, Carbamazepine, Phenytoin, St. John's Wort | Decreased progesterone levels due to CYP3A4 induction. May lead to therapeutic failure. | Major |
| Midazolam, Triazolam | Enhanced sedative effect of benzodiazepines due to additive CNS depression. | Moderate |
| Warfarin | Progesterone may alter anticoagulant effect; monitor INR closely. | Moderate |
| Antihypertensives | Progesterone may blunt the effect, leading to increased blood pressure. | Moderate |
| Insulin, Oral Hypoglycemics | Progesterone may decrease glucose tolerance; monitor blood sugar. | Moderate |
Same composition (Progesterone (500mg)), different brands: