---
title: "Letrozole"
description: "⚠️ The most potent AI on the market. Reserved for emergencies (acute gyno) or very high-dose testosterone cycles. The risk of crashing estrogen is high — use with extreme caution. Anastrozole is preferable for daily management."
lang: en
dateModified: 2026-05-25
canonical: https://anaprotokol.com/en/molecule/letrozole
---

# Letrozole

⚠️ The most potent AI on the market. Reserved for emergencies (acute gyno) or very high-dose testosterone cycles. The risk of crashing estrogen is high — use with extreme caution. Anastrozole is preferable for daily management.

**Catégorie** : Anti-œstrogène & SERM
**Voie d'administration** : Oral
**Demi-vie** : 2 jours
**Détection** : 2 semaines
**Aromatisation** : Non
**Progestine** : Non
**Hépatotoxique** : Non
**PCT requise** : Non

**Autres noms** : Letro, Femara

## Effets
- Very strong aromatase blockade (> 95%)
- Fast estrogen reduction
- Emergency gyno treatment

## Effets secondaires
- Estrogen crash (zero libido, joint pain, depression)
- Loss of bone density
- Degraded lipid profile

## Suppléments de soutien
- Vitamin D3
- Calcium
- Omega-3

## Synergies
- High-dose testosterone (difficult E2 control)
- SARMs (if secondary aromatization)

## À éviter
- Prolonged daily use
- If E2 is already low
- Prefer Anastrozole/Exemestane for routine use

## Dosage masculin
- Débutant : 0,5 mg EOD
- Intermédiaire : 1 mg EOD
- Avancé : 2,5 mg/j (urgence gynéco)

## Dosage féminin
Medical use only

**Fréquence** : EOD or as needed