03/03/2026
HAIR LOSS & HORMONES
What’s Really Happening
Hair growth is directly influenced by hormonal balance. When hormones shift, hair is often one of the first tissues to respond.
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ANDROGENS (Testosterone & DHT)
Testosterone converts into DHT (dihydrotestosterone) through the enzyme 5-alpha reductase. DHT can shrink hair follicles over time, a process called follicle miniaturization.
What happens:
• Growth phase shortens
• Hair becomes thinner
• Shedding increases
• Follicles produce finer, weaker strands
Patterns:
• Women: widening part, crown thinning
• Men: receding hairline, vertex balding
Important: Women do not need high testosterone to experience androgenic hair loss. Many are simply DHT sensitive.
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ESTROGEN
Estrogen helps prolong the hair growth (anagen) phase and supports thickness and shine.
When estrogen drops:
• Postpartum
• Perimenopause
• Menopause
• After stopping birth control
You may notice:
• Increased shedding
• Loss of density
• Overall thinning
Sudden shedding after hormonal shifts is called telogen effluvium.
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THYROID HORMONES
Both hypothyroidism and hyperthyroidism can cause:
• Diffuse thinning
• Brittle, dry hair
• Loss of outer third of eyebrows (common with hypothyroidism)
• Slow regrowth
Hair often improves once thyroid levels are properly optimized.
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CORTISOL (STRESS HORMONE)
Chronic stress increases cortisol, which pushes hair into the resting phase prematurely.
This can cause:
• Sudden shedding 2–3 months after stress
• Post-illness hair loss
• Emotional stress-related thinning
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INSULIN & METABOLIC HEALTH
High insulin levels increase androgen production and inflammation.
Common in:
• PCOS
• Insulin resistance
• Obesity
• Metabolic syndrome
Insulin imbalance can worsen DHT-related thinning.