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
SHBG binds estrogen and testosterone in the blood. The free, unbound fraction is what tissues actually use. Liver health, insulin and the pill all change SHBG.
Why it matters for women
Low SHBG means more free testosterone (common in PCOS and insulin resistance). High SHBG — typical on the combined pill — leaves too little free testosterone, causing low libido and mood symptoms.
Optimal range
40–80 nmol/L (non-pill users).
Standard lab range
Lab ranges run 20–155.
When it's high
- ↑Oral contraceptive use
- ↑Hyperthyroidism
- ↑Liver issues
- ↑Low free testosterone symptoms
When it's low
- ↓Insulin resistance
- ↓PCOS
- ↓Hypothyroidism
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.