Perimenopause

Gradual endocrine transition typically beginning mid-40s, lasting 4–10 years.

Environment changes

• Estrogen and progesterone fluctuation
• Sleep disruption (often first symptom)
• Metabolic rate changes
• Body composition shifts

Key considerations

• Sleep changes often precede hot flashes
• Protein and resistance training needs increase
• Cardiovascular risk begins to rise
• Hormone therapy timing matters (window of opportunity hypothesis)