Exemestane

Mechanism: Steroidal, suicidal (irreversible) aromatase inhibitor. Permanently deactivates the aromatase enzyme it binds to. New enzyme must be synthesised for estrogen production to resume -- no rebound when discontinued.

Dosage:

• On-cycle (symptom-based): 12.5 mg EOD or E3D
• Aggressive (rare): 25 mg EOD (risk of crashing E2)

Administration:

• Oral tablet -- MUST be taken with a fat-containing meal (absorption increases 40% with dietary fat)
• Do not take fasted

Key Notes:

• Suicidal inhibitor: no estrogen rebound when discontinued (advantage over Anastrozole)
• Slightly less lipid-negative than Anastrozole due to mild androgenic metabolite
• Same caution applies: only use with symptoms, never prophylactically
• Crashed E2 from Exemestane takes longer to recover (must wait for new enzyme synthesis, ~2-3 weeks)
• Has a mild androgenic metabolite (17-hydroxy-exemestane) which can help with libido
• Preferred by some over Anastrozole for the no-rebound property