12/17/2025
Causes of Low Progesterone (Outside of Perimenopause)
1. Anovulation (Not Ovulating)
Progesterone is only made after ovulation.
• No ovulation = no corpus luteum = low progesterone
• Very common and often missed
• Cycles may still be regular
Common causes of anovulation:
• Stress
• PCOS
• Thyroid dysfunction
• Insulin resistance
• Postpartum/breastfeeding
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2. Chronic Stress (Cortisol Steal)
Progesterone is the precursor to cortisol.
• Chronic stress diverts progesterone → cortisol
• Leads to low progesterone even with normal estrogen
• Symptoms:
• Anxiety
• Insomnia
• PMS
• Short luteal phase
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3. Short Luteal Phase
Ovulation occurs, but progesterone production is inadequate.
• Luteal phase