# Progesterone (Oral)

*Also known as: Prometrium, Oral P4*

Micronized oral progesterone; short half-life with high first-pass metabolism.

## Overview

Oral micronized progesterone (Prometrium) is the oral form of bioidentical progesterone used in feminizing hormone therapy, menopausal hormone replacement, and fertility protocols. Swallowed micronized progesterone is absorbed and carried to the liver, where extensive first-pass metabolism converts much of it to active metabolites including allopregnanolone, which accounts for the pronounced sedative effect of oral dosing. The compound has a roughly 23-hour half-life, peaks within roughly 90 minutes, and shows only about 10% bioavailability of parent progesterone because of that first-pass loss, so serum progesterone levels after oral dosing are far lower than the clinical and neurological effects suggest. Effects include endometrial protection in estrogen-containing therapy and a strong sleep and sedative action, while the dominant practical issues are daytime drowsiness and the limited serum progesterone achieved by the oral route. Harm reduction centers on taking it at bedtime given the sedation and on monitoring symptoms and endometrial safety rather than chasing a serum target alone.

## Pharmacokinetics

- **Model tier:** advanced
- **Half-life:** 0.9 days (22.78 hours)
- **Cmax:** 169.53 ng/mL
- **Tmax:** 0.1 days
- **Bioavailability:** 10%

## Dosing

- **Default dose:** 100 mg
- **Typical range:** 100–300 mg
- **Units:** ng/mL

## Source

- **Label:** Dovepress micronized P4
- **URL:** https://www.dovepress.com/pharmacokinetics-of-hard-micronized-progesterone-capsules-via-vaginal--peer-reviewed-fulltext-article-DDDT
- **Notes:** Multiplier applied to match study graphs.

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**Canonical URL:** https://anabolicdex.com/compounds/progesterone-oral
**Plot:** https://anabolicdex.com/plot?compound=progesterone-oral