Hair Health . Symptoms guide
Female Hair Loss: What to Test
Quick answer
Female-pattern hair loss is almost never caused by a single factor. The most useful first step is a combined panel covering iron studies, full thyroid function, vitamin D, B12, oestrogen and androgens. That single appointment highlights which underlying metabolic or hormonal factors need addressing to ensure your treatment plan targets the right biological areas.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, and other specialist society guidance where cited).
What this might be
- Iron deficiency. Most common reversible cause in women, often well before frank anaemia.
- Thyroid dysfunction. Both under and overactive thyroid cause diffuse loss.
- Androgenetic (female pattern). Widening central part. Worsens around perimenopause.
- Telogen effluvium. Triggered by post-partum, severe illness, crash diet, surgery, or grief.
- PMOS markers (formerly known as PCOS). Evaluates free androgen levels (via testosterone and SHBG) to see if elevated male hormones are contributing to hair thinning, alongside symptoms like irregular cycles or acne.
Common features that suggest this
- Widening part line
- Increased shedding on the pillow or in the shower
- Reduced ponytail thickness
- Brittle nails (iron clue)
- Cold intolerance or fatigue (thyroid clue)
- Irregular periods or acne (PMOS clue)
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
Days 2 to 5 of the menstrual cycle give the cleanest hormone baseline for pre-menopausal women. Post-menopausal women can test any day. Morning appointment recommended. Note: stage of the menstrual cycle can affect all hormones, iron and ferritin, zinc, CRP, ESR and the full blood count, so cycle day should be noted at the time of the draw to help with accurate interpretation.
Common questions
Should I check oestrogen if I am still having periods?
It is most informative around perimenopause (typically late 30s to mid 50s) or when cycles have become irregular. Below that, a basic hormone screen plus thyroid and iron is usually enough.
Do I need to stop the contraceptive pill before testing?
If you are on the combined contraceptive pill, testing reproductive hormones like oestrogen or progesterone is not informative, as the pill suppresses your natural levels and it takes 2 to 3 months without hormonal contraceptives for levels to return to baseline. Please tell us at booking so the clinical review accounts for this.
Is finasteride safe for women?
Finasteride is not licensed for women and carries a strict contraindication for those of childbearing potential, due to the risk of severe harm to a developing foetus. It is occasionally prescribed off-label by specialist consultants for post-menopausal women, but it is not a standard frontline option. Bloodwork, clinical review, and if needed referral to a specialist, is the foundation of that decision.
Related symptoms
Sources and further reading
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.