Quick answer: Ask your GP about four bloods: ferritin, TSH (thyroid), vitamin B12 and vitamin D. If you take biotin, tell your GP before the test. When the results come back, ask for the actual figures, not just "normal", and keep a copy to bring to your appointment.
This is the checklist from our ferritin video. If you commented BLOODS, here it is. Screenshot it, print it, or keep it open on your phone for your GP appointment.
The BLOODS checklist
Before your blood test
If you take biotin, or a hair gummy with biotin in it, tell your GP. Biotin can throw off blood test results.
Note roughly when your hair fall started. Shedding often starts two to three months after whatever triggered it, so the date helps.
Tell your GP if you have heavy periods or you're vegetarian.
Ask your GP about these four bloods
Ferritin (your iron stores)
TSH (your thyroid)
Vitamin B12
Vitamin D
When your results come back
Ask for the actual figure for each test, not just "normal".
Keep a copy, or a screenshot of the figures.
Bring them to your consultation with us.
Why these four bloods
Ferritin. Ferritin shows how much iron your body has in storage. Low ferritin is one of the most common things we find in women who are shedding. It matters most if you have heavy periods or you're vegetarian. Heavy periods and hair fall often go together.
TSH. This is the thyroid test. An underactive thyroid and an overactive thyroid can both cause thinning all over the head. If your hair fall comes with feeling cold and tired all the time, tell your GP.
Vitamin B12. The third of the four. Ask for it by name so it doesn't get left off the form.
Vitamin D. Low vitamin D is common in Northern Ireland's low-sunlight months. If you shed more every winter, it's worth checking.
Why "normal" isn't the end of it
A result can sit inside the normal range on the lab report and still be lower than what we look for when someone has hair fall. So "normal" on its own doesn't settle it. Ask for the figure, keep a copy and bring it in.
Test before you buy hair vitamins
Hair supplements only help when you're low in something. Get these four bloods done first, then decide. And if you're already taking biotin, mention it before your blood test.
Bloods normal, hair still falling?
Blood tests can't show a pattern of thinning or an inflamed scalp. Our scalp camera can. If your bloods look fine and you're still shedding, that's the point to book a scalp check.
Frequently asked questions
Which blood tests should I ask for if my hair is falling out?
The four we ask every hair fall client to bring are ferritin, TSH, vitamin B12 and vitamin D. Your GP decides which tests are right for you.
My GP said my iron is normal. Is that enough?
Ask for one number: your ferritin. A result inside the normal range can still be lower than what we look for in hair fall.
Can biotin affect my blood test?
Yes. Biotin can throw off blood test results, so tell your GP you take it before you're tested.
Do I need my results before I book?
No, you can book any time. If you have results, bring them. They help us build your plan.
Book in and bring your results
Book a hair and scalp analysis at Tess Hair and Scalp Clinic, 77a Botanic Avenue, Belfast, or call 028 9096 4731. See our treatments and prices, or watch the ferritin video.
About the author: Theresa Anthony is the certified trichologist at Tess Hair and Scalp Clinic, 77a Botanic Avenue, Belfast BT7 1JL. This checklist is general information, not medical advice. Your GP decides which blood tests you need.
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