Is there a blood test for hair loss?
There’s no single blood test for hair loss. Instead, blood tests look for the things that can cause or worsen it: low iron, a thyroid problem, low vitamin levels or a hormonal imbalance. Finding and correcting one of these can make a real difference to your hair.
Not everyone with hair loss needs blood tests, and normal results don’t mean nothing can be done. As a trichologist, I use your history and a close look at your hair and scalp to decide which tests would help, then explain your results in the context of your hair.
I don’t take blood myself. Tests can be arranged through your GP, or you can have them done privately, and I’ll help you understand the results.
The tests most often checked
- Full blood count
- Ferritin (iron stores)
- Thyroid function
- Vitamin D
- Vitamin B12 and folate
- Hormones, for some women
Which ones you need depends on your symptoms and history.
Which blood tests are needed for hair loss?
These are the blood tests most often useful for hair loss. You won’t need all of them: the right ones depend on your symptoms, health and history.
| Test | What it checks | Why it matters for hair |
|---|---|---|
| Full blood count (FBC) | Anaemia, infection and general health | Anaemia can cause shedding and thinner hair. |
| Ferritin | Your body’s iron stores | Low ferritin is one of the most common causes of shedding, especially in women. Iron deficiency and hair loss. |
| Thyroid function (TSH, free T4, sometimes free T3) | An underactive or overactive thyroid | Both can cause diffuse thinning. Thyroid hair loss. |
| Vitamin D | Vitamin D levels | Low levels are linked with shedding and with alopecia areata. |
| Vitamin B12 and folate | Vitamins needed to make new cells | Deficiency can affect hair growth, particularly with a restricted diet. |
| Zinc | Zinc levels | Occasionally low, and linked with shedding. |
| Hormones (for example testosterone, SHBG, DHEA-S) | Androgen levels in women | Useful when hair loss comes with irregular periods, acne or extra facial hair, as in PCOS. |
| Inflammatory and autoimmune markers | Inflammation or autoimmune activity | Sometimes checked with patchy hair loss or an inflamed scalp. |
Blood tests for hair loss in women
Women are more likely to have low ferritin, thyroid problems and hormone-related hair loss, so the first tests are usually a full blood count, ferritin, thyroid function and vitamin D.
Hormone tests can help if your hair loss comes with irregular periods, acne or extra facial or body hair. Hair changes after childbirth or around the menopause are often hormonal too, though blood tests aren’t always needed to explain them.
Blood tests for hair loss in men
Most hair loss in men is male pattern baldness, which is genetic and doesn’t show up in blood tests.
Tests are more useful when hair loss is sudden, diffuse or patchy, or if you feel unwell, have lost weight or follow a restricted diet. A full blood count, ferritin, thyroid function and vitamin D are the usual starting point.
How to get a hair loss blood test
Through your GP
Your GP can arrange tests if they think they’re needed, particularly if you feel unwell or your hair loss is sudden. Ask for copies of your results.
Privately
Private clinics and laboratories offer hair loss blood test panels. A sample taken from a vein is more reliable than some home finger-prick kits.
With my help
At your consultation I’ll recommend which tests would be useful and why, and liaise with your GP or explain how to have them done privately.
My blood tests are normal, but I’m still losing hair
This is very common, and it doesn’t mean nothing can be done. Many causes of hair loss don’t show up in blood tests at all, including pattern hair loss, shedding after stress or illness, scalp conditions, breakage and tight hairstyles.
A result inside the laboratory’s normal range also isn’t always ideal for hair. Ferritin is the classic example: a level near the bottom of the normal range may be fine for your general health but still too low for healthy hair growth.
That’s where a trichologist helps: looking at your results alongside your history and your hair and scalp, to find what’s really going on. What happens at a consultation.
What patients say
Questions about hair loss blood tests
If yours isn’t here, send me a message and I’ll get back to you.
Is there a blood test for hair loss?
There’s no single test, but blood tests can find causes of hair loss such as low iron, thyroid problems, low vitamin levels or hormonal imbalance.
Which blood test is required for hair loss?
Usually a full blood count, ferritin, thyroid function and vitamin D, sometimes with vitamin B12, folate, zinc or hormone tests, depending on your symptoms.
What blood tests are done for female hair loss?
Typically a full blood count, ferritin, thyroid function and vitamin D, with hormone tests if there are signs such as irregular periods, acne or extra facial hair.
Is there a blood test for alopecia?
Alopecia areata is diagnosed by examining the hair and scalp, not by a blood test. Tests are sometimes used to check for related thyroid or autoimmune problems.
Can blood tests show hair loss caused by stress?
Not directly. Stress-related shedding doesn’t show up in blood tests, but tests can rule out other causes such as low iron or thyroid problems.
Do you take blood tests?
No. Tests can be arranged through your GP or privately. I’ll recommend which tests would help and explain your results.
Should I bring my results to my appointment?
Yes, please bring any blood test results from the last six months, or send them before a video consultation.
Let’s find out what’s going on
Book online at a time that suits you. If you have a question first, send me a message.