By If you’ve ever had your iron levels tested, you may have noticed something strange—the “normal” ferritin range is ridiculously wide. Depending on the lab, it might be 10 to 200 ng/mL for women or 15 to 400 ng/mL for men. That’s not just a small variation—it’s an enormous range!
So what’s the deal? Why is someone with ferritin at 20 ng/mL considered “fine,” while another person at 200 ng/mL is also totally “normal”? And more importantly—why do some people who are in so-called “normal” ranges still feel terrible and have almost all of these symptoms?
Let’s break it down.
1. Ferritin Is Both an Iron Storage Protein & an Inflammation Marker
Ferritin’s main job is to store iron and release it when your body needs it. Sounds simple, right? But here’s the catch—ferritin also rises when there’s inflammation. That means your ferritin level isn’t just about iron—it can also be affected by infections, autoimmune diseases, liver issues, and even stress.
So if you get a blood test and your ferritin comes back at 120 ng/mL, does that mean your iron levels are great? Maybe. But if you have chronic inflammation, your ferritin could be artificially high, and you might still be low in usable iron.
On the flip side, if your ferritin is 20 ng/mL, your doctor might say it’s “normal.” But many people at this level feel exhausted, dizzy, and experience hair loss and brain fog—because while 20 ng/mL might be “acceptable” by lab standards, it’s often too low for proper function.
Before you go “Hey, are you a doctor? How do you know that?” No I am not, I am just a 52-year-old woman with lifelong anxiety and ADHD problems whose symptoms got immeasurably worse four years ago and who recently discovered why.
2. “Normal” Ranges Are Based on Population Averages, Not Optimal Health
Here’s something most people don’t realize: Lab reference ranges aren’t based on what’s ideal for your body. They’re based on the general population.
And let’s be honest—the general population isn’t exactly thriving.
If the average person getting tested has chronic inflammation, nutritional deficiencies, and poor health, the lab ranges reflect that. That’s why you’ll see reference ranges allowing ferritin as low as 10 or 12 ng/mL—even though at that level, many people feel absolutely wrecked.
Many functional medicine doctors and iron specialists say that for optimal energy, brain function, and hair growth, ferritin should be:
✅ 50–100 ng/mL for most women
✅ 70–150 ng/mL for active people or those with heavy periods
✅ Above 100 ng/mL for endurance athletes
So if your ferritin is technically “normal” but under 50, and you’re feeling awful, it might be time to push for treatment.
3. Women Need Higher Ferritin Levels Than Men
Another reason for the massive range? Men and postmenopausal women don’t lose iron monthly, but menstruating women do.
🚨 Fact: A single heavy period can drop ferritin by 10–20 points.
That means a woman with regular cycles needs higher iron stores than a man of the same age—yet they’re often lumped together in lab reference ranges.
For women who still get periods, ferritin levels below 40–50 ng/mL often lead to:
- Chronic fatigue (even after a full night’s sleep)
- Hair shedding (especially at the temples and crown)
- Restless legs at night
- Dizziness or lightheadedness
- Shortness of breath with mild exertion
If you’re dealing with these symptoms and your ferritin is “normal” but under 50, your body is probably running on fumes.
4. Different Labs Use Different Cutoffs (And Some Countries Have Stricter Standards!)
Did you know that in Japan and parts of Europe, doctors consider ferritin below 30 ng/mL as iron deficiency? But in the U.S., some labs still say 10–15 ng/mL is fine.
Let’s be real—if other countries are treating ferritin under 30 as low, why are some American doctors telling people that ferritin of 12 is perfectly okay?
In fact, research shows that many people with ferritin below 50 still experience iron deficiency symptoms, even without full-blown anemia. So if your doctor brushes off your concerns because your ferritin is “within range,” you might need to advocate for yourself.
5. Athletes and Active People Need Even More Iron
If you’re a runner, weightlifter, or even just someone who walks a lot, you burn through iron faster than the average person.
✅ Why? Exercise increases red blood cell turnover, and iron is needed to replace those cells.
✅ Sweating depletes iron, too.
✅ More muscle mass = higher iron needs because muscles rely on iron to transport oxygen.
That’s why many sports medicine doctors recommend athletes keep ferritin above 70–100 ng/mL for peak performance. If you’re working out regularly but feel unusually exhausted, it might not just be “overtraining”—it could be low iron.
So… What’s the Takeaway?
- The “normal” ferritin range is huge because it accounts for both iron stores and inflammation markers—but that doesn’t mean all levels within that range are optimal.
- Many people feel iron-deficient at ferritin levels below 50, even if their doctor says they’re “fine.”
- Women with periods, athletes, and people with chronic fatigue or hair loss often need ferritin levels closer to 70–100 ng/mL for proper function.
- If your ferritin is low-normal but you feel awful, advocate for treatment—because being in the “normal range” doesn’t mean your body is functioning well.
Next Steps: Should You Get Your Ferritin Tested?
If you have fatigue, hair loss, dizziness, or restless legs, it’s worth getting a full iron panel, including:
✅ Ferritin (iron storage)
✅ Serum iron (circulating iron)
✅ Total iron-binding capacity (TIBC) (how well your body can use iron)
✅ Transferrin saturation (how much iron is available for use)
If your ferritin is below 50 ng/mL, especially if you’re having symptoms, it’s time to take action.