Nutrients

Ferritin test

Ferritin shows how much iron your body has stored for later.

Included in every $199 draw

Key benefits of ferritin testing

Spots low iron stores before anemia shows up.
Explains fatigue, hair shedding, restless legs and brain fog.
Guides whether iron supplements make sense, and when to stop.
Flags iron overload that can quietly harm organs.
Reads best with iron, TIBC and a full blood count, which Insyght includes.

What is ferritin?

Ferritin is a protein that stores iron inside your cells, mostly in the liver, spleen and bone marrow. A small amount circulates in blood and mirrors your total iron reserve.

Why ferritin matters

Iron carries oxygen and powers energy production. When stores run low, you can feel exhausted long before your hemoglobin drops.

What your ferritin results mean

Low: iron stores are depleted. Common causes are heavy periods, low dietary iron, poor absorption and endurance training.
In range: your iron reserves look adequate.
High: can mean inflammation, liver stress, metabolic syndrome or true iron overload such as hemochromatosis.
Context matters: ferritin rises with inflammation, so a "normal" result can hide low iron. Insyght reads it with hs-CRP.

Standard vs. optimal range

	Women	Men
Standard lab range	About 15 to 150 ng/mL (varies by lab)	About 30 to 400 ng/mL (varies by lab)
Insyght optimal range	Set by the Insyght medical team	Set by the Insyght medical team

LowHigh

Lab reference rangeYour optimal range

A value can read normal on a standard panel and still sit outside optimal. Insyght flags it.

Do I need a ferritin test?

Exhausted no matter how much you sleep, losing more hair than usual, or craving ice? Ferritin is one of the most common hidden causes of fatigue, especially in women.

Find out if low iron is behind your fatigue

Insyght tests ferritin, iron, TIBC and your full blood count together, reviewed by a physician. $199 a year.

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Similar biomarkers

IronTIBCHemoglobinhs-CRP Vitamin D

Frequently asked questions

Can I have low ferritin without anemia?

Yes. Iron stores drain first. Hemoglobin often stays normal until stores are nearly empty.

Should I take iron if my ferritin is low?

Often, but only after testing. Too much iron is harmful, so dose and duration should be guided by your results.

Why is my ferritin high?

Inflammation, liver stress and metabolic issues are more common causes than true iron overload. Your physician will look at the full picture.

Medically reviewed by Dr. Maria Gutierrez Horn, MD, FACE, Board-certified endocrinologist, in practice since 2001. Last updated September 28, 2026.