Educational information from Her Form — reviewed for accuracy by our health specialists.
Not a substitute for personal medical advice. Optional 1:1 consults with Robyn, our consulting women's-health specialist, are available on request.
What it is
Progesterone is produced by the corpus luteum after ovulation in the second half of the cycle. It balances estrogen, supports early pregnancy and has a calming effect on the nervous system.
Why it matters for women
Progesterone is the first hormone to decline in perimenopause. Low luteal-phase progesterone is linked to PMS, anxiety, insomnia, short cycles and difficulty conceiving.
Optimal range
Luteal phase (day 21 of a 28-day cycle): >10 ng/mL confirms ovulation; 15–25 is robust.
Standard lab range
Most labs only flag <1 ng/mL — luteal-phase context is essential.
When it's high
- ↑Drowsiness
- ↑Bloating
- ↑Breast tenderness (rare unless supplementing)
When it's low
- ↓PMS, anxiety, insomnia
- ↓Spotting before periods
- ↓Short luteal phase (<10 days)
- ↓Difficulty conceiving
- ↓Early miscarriage
References
- Endocrine Society — Female hormone health— Sex hormone assessment and interpretation in women
- Jean Hailes for Women's Health— Comprehensive women's hormone health guidance
- RANZCOG — Women's health guidelines— ANZ clinical standards for reproductive-age women
- NICE — Women's health guidelines— Evidence-based hormone and reproductive health guidance
References are provided for educational context only. Always interpret results with a qualified healthcare professional.
A note on interpretation. Ranges above are what our health specialists works to in healthy women. They are not a diagnosis — a single result always needs context from your symptoms, cycle phase and other markers.