The Blood Test That Changed My Hair (And What Most Women Don’t Know About Hair Loss)
For most of my life, my hair refused to grow past my bra strap.
It made no sense.
The top of my hair felt thick and dense, but the ends were always thin. No matter how careful I was, my hair seemed to stall at the same length.
Like many women, I assumed the answer was external.
Better shampoo.
Less heat.
More oil treatments.
More patience.
But after removing my hip-length extensions and starting my real hair journey, something unexpected happened.
Months passed… and my hair barely moved.
That’s when I stopped experimenting with products and started looking inside my body instead.
I ordered a comprehensive blood test.
What I discovered completely changed the way I approach hair growth.
The Number Every Woman With Hair Loss Should Know
One marker stood out more than anything else:
Ferritin.
Ferritin is the storage form of iron in the body. While iron levels fluctuate throughout the day, ferritin tells us how much iron your body has stored for long-term use.
Hair follicles depend heavily on those reserves.
If ferritin levels drop too low, hair follicles can prematurely enter the resting phase, which leads to:
• increased shedding
• slower regrowth
• difficulty growing hair past a certain length
What surprised me the most was that the ferritin level required for healthy hair growth is often much higher than what labs consider “normal.”
Many labs consider ferritin levels as low as 20 ng/mL normal for women.
But many dermatologists and hair specialists recommend levels closer to 50–70 ng/mL (or even higher) to support strong hair growth.
In other words:
You can be medically “normal” and still not have the nutrient reserves needed to grow the hair you want.
The Hidden Factor Most People Never Consider
During my research, I also discovered something fascinating.
Certain intestinal parasites can contribute to iron depletion.
Some parasites attach to the intestinal wall and feed on blood or interfere with nutrient absorption. Over time, this can lower iron stores and ferritin levels—sometimes without obvious symptoms.
Hair follicles are extremely sensitive to these changes.
If the body is losing nutrients faster than it can replace them, the hair follicle simply doesn’t have the resources needed to sustain growth.
Hair is one of the most honest indicators of what’s happening internally.
Your hair always tells the truth about your biology.
Why “Normal” Blood Tests Can Be Misleading
Another lesson I learned is that medical lab ranges are designed to detect disease.
They are not designed to optimize beauty or hair growth.
Hair follicles sit low on the body’s survival priority list. If nutrients are limited, your brain and organs receive them first.
Hair receives what remains.
That means a person can technically be healthy… while their hair still struggles to grow.
Understanding this changed everything for me.
Instead of guessing, I started measuring.
Instead of following trends, I followed biology.
And slowly, my hair began responding.
Shedding decreased.
Density improved.
Growth accelerated.
But more importantly, I realized that hair growth is not just a cosmetic journey.
It’s a biological one.
The Hair Ritual Philosophy
One of the core ideas in my book The Hair Ritual is this:
Hair growth begins internally.
You can apply every oil, mask, and treatment in the world, but if your body lacks the nutrients required to build hair fibers, those treatments can only go so far.
When the internal environment changes, the hair eventually reflects it.
Hair always tells the truth.
Download the Full Chapter
This article is adapted from Chapter 7 of my upcoming book, The Hair Ritual.
In the full chapter I explain:
• The blood tests that revealed my hair growth barriers
• The exact supplements I used to correct deficiencies
• Why ferritin levels matter more than most people realize
• The connection between gut health, parasites, and hair growth
You can download the entire chapter for free below.
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Download the full chapter here: Chapter 7 Download
If you’ve struggled to grow your hair past a certain length, the problem might not be your products.
It might be your biology.
And once you understand that… everything changes.
— Air