# Progesterone (Vaginal)

*Also known as: Vaginal P4*

Vaginal micronized progesterone; bypasses much first-pass metabolism.

## Overview

Vaginal micronized progesterone is a parenteral route of bioidentical progesterone used in feminizing hormone therapy, menopausal hormone replacement, and luteal-phase fertility support. By delivering progesterone through the vaginal mucosa and a direct first-pass uterine effect, the route bypasses the hepatic first-pass metabolism that dominates oral dosing, achieving meaningful local uterine exposure and a different systemic metabolite profile with far less sedation. The compound has a roughly 21-hour half-life, peaks within roughly 6 hours, and shows about 50% bioavailability, supporting once or twice daily dosing. Effects include endometrial protection with markedly less daytime drowsiness than oral micronized progesterone, while the main practical issues are local irritation and discharge that can affect tolerability and adherence. Harm reduction centers on the understanding that serum progesterone after vaginal dosing under-represents the local uterine effect and on monitoring endometrial safety through clinical assessment rather than serum progesterone alone.

## Pharmacokinetics

- **Model tier:** advanced
- **Half-life:** 0.9 days (20.6599999992 hours)
- **Cmax:** 12.3 ng/mL
- **Tmax:** 0.3 days
- **Bioavailability:** 50%

## Dosing

- **Default dose:** 100 mg
- **Typical range:** 100–400 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

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