What Is Ferritin?
Ferritin is your body’s iron storage protein. Think of it as your iron reserve tank.
When your tank is full, your cells have what they need to produce energy, grow hair, regulate mood, and keep your brain sharp.
When your tank is low… everything suffers. Slowly, quietly, and in ways that are incredibly easy to dismiss.
Ferritin is different from serum iron, which is the iron currently circulating in your blood. You can have normal serum iron and depleted ferritin at the same time. This is why so many women are told their iron is fine while their ferritin tells a completely different story.
What Does the Lab Reference Range Actually Mean?
Here’s where it gets frustrating.
Most standard lab ranges list ferritin as normal anywhere from 12 to 300 ng/mL for women.
That is an enormous range. And the bottom of it 12, is barely above empty.
The reference range was not designed to tell you where you’ll feel your best. It was designed to flag disease. Specifically, iron deficiency anemia — which doesn’t appear until ferritin drops very low and hemoglobin starts to fall.
So a ferritin of 14 won’t trigger an anemia diagnosis. It won’t show up as abnormal on your lab report. Your doctor will tell you everything looks fine.
But a ferritin of 14 is not fine. It just isn’t anemia.
Those are two very different things.
So What Is Actually Optimal?
This is the question I wish someone had answered for me years ago.
Based on clinical research and what I’ve seen working with women in practice, most women feel their best with ferritin between 70 and 100 ng/mL.
Some women particularly those dealing with significant hair loss may need ferritin above 100 before they see meaningful hair regrowth.
Below 50, symptoms are common. Below 30, they’re almost universal. And below 20, most women are struggling significantly even if their lab report says normal.
The gap between 12 and 70 is where most of my patients live. It’s also where most of the suffering happens. And it’s almost entirely invisible to standard bloodwork interpretation.
Why Doesn’t My Doctor Tell Me This?
This is not a criticism of doctors. It’s a systemic issue.
Medical training is built around diagnosing and treating disease. A ferritin of 22 isn’t a disease. So it doesn’t trigger a clinical response.
What it does trigger, fatigue, brain fog, hair loss, anxiety, heavy periods, cold hands and feet those symptoms get attributed to stress, aging, hormones, depression. Anything but the actual cause.
I’ve been a Physician Assistant for over a decade. I know how to read labs. My ferritin was 6 before I figured out what was happening to me.
I was dismissed too.
Symptoms of Low Ferritin (Even With “Normal” Labs)
If your ferritin is below optimal, you may experience some or all of the following:
Fatigue that doesn’t improve with sleep: a deep, cellular exhaustion that caffeine can’t touch.
Hair shedding: more than usual in the shower, on your pillow, on your brush. Hair follicles are highly sensitive to iron depletion.
Brain fog: difficulty concentrating, word-finding issues, feeling mentally slow.
Anxiety or restlessness: iron is required for neurotransmitter production. Low ferritin can look like anxiety or even depression.
Heavy or worsening periods: heavy bleeding depletes iron, which lowers ferritin further, which can worsen bleeding. It’s a cycle.
Cold hands and feet: poor circulation and low energy production go hand in hand with depleted iron stores.
Shortness of breath with mild exertion: your cells are working harder to do less.
If several of these sound familiar… your ferritin is worth a closer look.
What Labs Should You Actually Request?
A basic iron panel often doesn’t include ferritin. You have to ask for it specifically.
Here’s what to request at your next appointment:
- Ferritin — your iron storage levels
- Serum iron — iron currently in circulation
- TIBC (Total Iron Binding Capacity) — how much iron your blood can carry
- Transferrin saturation — what percentage of your iron-carrying capacity is actually being used
- CBC (Complete Blood Count) — to rule out anemia
Together these give you a complete picture. Ferritin alone is the most important single number but the full panel tells the full story.
What to Do If Your Ferritin Is Low
First, don’t panic. Ferritin is recoverable. It takes time, the right protocol, and consistency. But it moves.
A few things to know going in:
The form of iron you take matters. Not all iron supplements absorb the same way. Most women are taking the form that causes the most side effects with the least absorption.
Timing matters. Iron competes with other minerals for absorption. Coffee, calcium, and high-fiber foods can all block uptake. When you take your supplement is as important as what you take.
The timeline is longer than you think. Ferritin recovery typically takes 3 to 6 months of consistent supplementation. Women who quit after 6 weeks — because the number hasn’t moved yet, often never recover. It’s moving. It’s just slow.
Heavy periods change everything. If you’re losing significant iron every month, you need to account for that loss in your recovery plan. Replenishing without understanding your cycle will affect your progress.
Where to Start
If you’re reading this and recognizing yourself in these symptoms, here’s what I’d recommend:
Step 1: Request a full iron panel at your next appointment. Specifically ask for ferritin.
Step 2: Grab my free Iron Lab Cheat Sheet, it tells you exactly what to request, what the numbers mean, and what optimal looks like.
Step 3: If you’re ready to build a real recovery plan, the Iron Recovery App walks you through everything, the right labs, the right supplement form for your body, your personal recovery timeline, and a step-by-step protocol. Click here.
The Bottom Line
Normal is not the same as optimal.
A ferritin of 14 won’t show up as flagged on your lab report. But it’s not enough to feel well, grow hair, think clearly, or get through the day without crashing.
If you’ve been told your labs are fine while your symptoms is telling you otherwise…
Trust your body. It was right.
About the author: Sabine is a PA-C with over a decade of experience in internal medicine. She is the founder of Thrively Health and creator of the Iron Recovery App. Her ferritin was 6. It’s 73 now. She built the protocol that got her there and then built an app around it so other women could do the same.