Written by &you Labs Team
Updated September 6, 2026
Say you feel tired all the time. Your hair is thinning. Workouts feel harder than they should. Your standard CBC, a common blood count test, came back "normal." One marker may still be off. Ferritin shows how much iron your body has stored. It drops first when you run low on iron, often years before you become anemic. It explains a lot of unexplained tiredness, especially in women.
This guide covers what ferritin is, what your number means, and how to read it in context.
Ferritin measures your stored iron. It drops first when iron runs low. Hemoglobin, the protein that carries oxygen in your blood, moves only later. The healthy target is 50 to 150 ng/mL. The standard range allows numbers as low as 11 in women, and 24 in men. This misses many people who still run low on iron. Low ferritin can cause fatigue, hair loss, brain fog, low exercise stamina, and weak thyroid function. This happens even with a normal hemoglobin.
Ferritin is a protein that stores iron inside your cells. Your blood ferritin level tracks your total body iron well, in most cases.
When you take in too little iron, or lose more than you take in, ferritin drops first. Your body draws on stored iron to keep making hemoglobin. Hemoglobin stays normal until your iron stores are almost gone. This is why a CBC alone can miss early iron loss.
Stage 1 is iron depletion. Ferritin is low, but hemoglobin is still normal. This stage often causes symptoms, such as fatigue and hair loss. A CBC alone will miss it.
Stage 2 is iron-deficient blood cell production. Ferritin stays low. MCV, a red blood cell size marker, starts drifting down. Hemoglobin is still in range, but trending downward.
Stage 3 is iron deficiency anemia. Ferritin is low. Hemoglobin drops under 12 in women, or under 13 in men. This is classic anemia.
Stage 1 is the most common stage in real life. Only a ferritin test can catch it.
Ferritin (ng/mL) | Category | What to do |
|---|---|---|
Under 15 | Severely low | Find the cause, start iron |
15 to 29 | Low | Start iron, find the cause |
30 to 49 | Below target | Iron often helps, especially with symptoms |
50 to 150 | Healthy target | Keep it steady |
150 to 300 | High end | Usually from supplements, not a problem |
Over 300 | Investigate | Check for inflammation or other causes |
Most lab reports here use a standard range that starts at 11 ng/mL for women, and 24 for men. Both are far below the healthy target of 50.
You can have these symptoms even with a normal hemoglobin:
Many people blame these on stress or aging, instead of getting tested.
A standard CBC checks your hemoglobin and red cell counts, but not ferritin. It is a separate test. A doctor must order it by name. On many standard checkup panels here, doctors only order it once anemia already shows up. By then, the shortage has often built up for a while.
The result: many Filipino women, and some men, carry low ferritin for years. All the while, they are told their blood work is "normal."
This is the top cause in women of childbearing age. Heavy or long periods, fibroids, and other conditions all play a part.
Plant foods give you a form of iron your body absorbs less well. Picky eating, or a diet low in protein, adds to the risk. This is common in teens and young adults.
Iron needs roughly double during pregnancy. Low iron is common without a supplement.
This is less common, but important. Causes include stomach ulcers, gut inflammation, hemorrhoids, celiac disease, and, in adults over 50, colon cancer.
Long distance runners and other endurance athletes lose small amounts of blood and iron over time.
Lower stomach acid makes it harder to absorb iron from food.
These reduce how much iron your gut can take in.
Ferritin also rises with inflammation, your body's response to stress or illness. Someone with ongoing inflammation can have a high ferritin, even with real iron deficiency underneath.
Watch for this pattern:
This pattern is called anemia of chronic inflammation. The iron is locked away, not truly missing. Treatment targets the inflammation, not iron pills. For an accurate read, always check ferritin alongside hs-CRP.
Heavy periods may need a doctor's input. A low-iron diet needs food changes and a supplement. New gut symptoms, or new low ferritin in a man or a postmenopausal woman, need a gut workup.
New research shows taking iron every other day works as well as daily, with fewer stomach side effects.
Hemoglobin recovers within 4 to 6 weeks if you were anemic. Ferritin recovers more slowly, over 12 or more weeks. Keep taking iron until ferritin passes 50, then switch to a lower maintenance dose. A full panel makes it easy to track this progress.
This suits severe deficiency, gut absorption problems, or ongoing heavy losses. This is a decision to make with your doctor.
A frequent profile looks like this:
This is the most common pattern we see. It is also the one most often missed by standard testing. Low iodine can weigh on your thyroid too. Here is how an iodine shortage leads to thyroid problems. See the full list of markers on your panel on our biomarker page.
Every &you Labs panel checks ferritin by default. It also checks hs-CRP, a full blood count, and other markers. Your report shows your value, both ranges, a read that accounts for inflammation, and clear supplement guidance.
By the standard range, above 11 in women, this reads as "normal." By the healthy target, 50 to 150, it counts as low. Say you have symptoms, such as fatigue or hair loss. A 12 week course of iron, with a retest, is a fair next step.
Energy often improves within 4 to 8 weeks of steady iron use. Hair shedding usually improves over 3 to 6 months. Ferritin itself takes 12 or more weeks to recover.
If you know you lose iron through monthly periods, a low maintenance dose is reasonable. To confirm and correct real deficiency, testing first rules out other causes, such as low B12 or inflammation.
Adult men do not lose iron through periods. New low ferritin in a man needs a closer look. The cause could be gut bleeding or a poor diet. Taking iron without a confirmed low level is usually not a good idea for men.
A ferritin above 300 needs a closer look. Common causes are inflammation, a genetic iron overload condition, liver disease, or past blood transfusions. Check it alongside hs-CRP and transferrin saturation.
The &you Labs Team combines medical science with personal care. We help Filipinos understand their health markers with blood work analysis that is easy to follow, whole person support, and health expertise built for Filipino life.
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