What Ferritin 8 Means Clinically
Ferritin is your body's main iron storage protein. The normal range is typically 12–150 µg/L for most adults, though laboratories vary slightly. A result of 8 µg/L is below even the lower limit of this range — meaning your iron stores are not just low, they are essentially empty.
At ferritin 8, your body has been drawing on reserves for some time. If your haemoglobin is still normal, it means your body has been compensating by prioritising iron for red blood cell production over other functions — but this compensation has limits, and at ferritin 8 you are very close to them.
Clinical context: ferritin 8 µg/L
This is below the lower limit of the normal range (12 µg/L). Most clinical guidelines classify ferritin below 30 µg/L as absolute iron deficiency, and below 12 µg/L as severely depleted stores. At ferritin 8, the case for treatment — either oral iron or IV infusion — is almost always clear. The question is which treatment is appropriate for your situation.
Symptoms You're Likely Experiencing at Ferritin 8
Iron is needed for far more than red blood cell production. It's involved in energy metabolism, thyroid function, cognitive performance, and immune regulation. At ferritin 8, deficiency in all these areas is typical:
Energy & Cognitive
- Severe, persistent fatigue
- Difficulty concentrating — "brain fog"
- Low mood, irritability, anxiety
- Inability to exercise at previous capacity
Physical
- Breathlessness on mild exertion
- Heart palpitations
- Significant hair thinning or shedding
- Restless legs at night
- Cold hands and feet
Iron Tablets vs IV Infusion at Ferritin 8
Both oral iron and IV infusion are treatment options. At ferritin 8, however, there are strong clinical reasons to favour an infusion in most cases:
| Iron Tablets | IV Iron Infusion | |
|---|---|---|
| Time to restore ferritin | 3–6 months | 4–6 weeks |
| Depends on gut absorption | Yes — unreliable | No — bypasses gut |
| GI side effects | Common (nausea, constipation) | None |
| Dose precision | Low | High — Ganzoni-calculated |
For patients with ferritin 8 who have significant symptoms, an IV infusion is typically the more appropriate option — particularly if you have any history of gut conditions, have previously tried tablets without success, or need faster symptom relief.
How Many Infusions Will You Need?
The number of infusions depends on your total iron deficit, calculated using the Ganzoni Formula from your blood test results. Use our free Iron Deficit Estimator to get your personalised estimate:
What to Expect at Your Appointment
At Lambert Medical Practice, we review your blood results before any treatment is prescribed. If your ferritin is 8, we will confirm the deficiency, check your haemoglobin and TSAT, calculate your iron requirement using the Ganzoni Formula, and — if clinically appropriate — administer the first infusion at the same appointment.
A follow-up blood test is arranged at Week 6 to confirm your ferritin has reached target. For patients with ongoing iron losses (heavy periods, inflammatory bowel disease), your GP will advise whether maintenance infusions are needed.