When we talk about iron, we’re not just talking about the iron circulating in the blood today – although that’s important too – we’re talking reserves. That’s ferritin.

Ferritin is a protein that stores iron safely inside and releases it when it’s needed. Think of it like a savings account: when daily expenses (your red blood cells, your muscles, your hormones, your brain, your thyroid) need iron, they first take it from your blood. As that decreases, your body seeks to top it up via drawing from the iron you have stored, which means pulling it out of ferritin. Without enough ferritin stores you’re constantly living “pay cheque to pay cheque” with iron – and it doesn’t take long before symptoms show up.

The laboratory “normal” range for ferritin for adult women is 20–220 µg/L. Yet in my clinical experience, most women feel their best when ferritin sits between 50–150 µg/L. Below 50 µg/L, the body often whispers to let you know more is needed – fatigue, low mood, restless legs, poor sleep. Below 30 µg/L, those whispers tend to become shouts. This blood work picture is amplified if transferrin, a taxi that drives iron around, is also elevated, or on the higher end inside the normal range. The transferring normal range for adult women is 2 – 3.6 g/L and once this goes above 2.6 g/L, see it as a sign of iron hunger.

Why traditional iron supplements often fall short

When ferritin is lower than ideal, supplementation is usually required to rebuild iron stores so you have a decent back-up battery. The challenge is that traditional iron supplements rarely move the needle quickly, and they often come with side effects that deter people from staying consistent.

Most conventional supplements deliver what’s called free iron into the gut. Free iron can drive inflammation, which the body naturally wants to avoid, so it raises a hormone called hepcidin. Hepcidin acts like a gatekeeper, shutting down further absorption to protect you from overload.

The trouble is that this leaves much of the iron stranded in the gut, where it can trigger constipation, nausea or discomfort, rather than being absorbed into the bloodstream and able to be stored (in ferritin). Copper is also needed for iron to move into storage. These are just some of the reasons why improvements in blood work, as well as how you feel, can be so slow, even when supplements are taken faithfully. In my clinical experience, it wasn’t unusual for ferritin to creep from 14 µg/L to just 18 µg/L after 2 months on traditional iron tablets.

The difference with ferritin-iron, sourced from organic peas

Ferritin-iron sourced from organic peas for use in nutritional supplements, is different because the iron comes naturally wrapped in the ferritin protein shell. The majority of ferritin-iron is absorbed intact (as a whole) by gut cells through a unique mechanism, unlike every other form of iron. This bypasses the usual absorption hurdles that come with other forms of iron and gut cells aren’t exposed to free iron.

Because it’s delivered in a form that protects gut cells, ferritin-iron is:

• Better tolerated – far less likely to cause constipation or gut irritation
• More bioavailable – absorbed and stored more efficiently
• Safer – avoids oxidative stress and inflammation in the gut, since it isn’t “flooding” gut cells with free iron

This means you don’t need high doses to get results. Smaller amounts have been clinically shown to restore healthy iron status, including ferritin stores, allowing energy, mood and sleep to fall back into place – all powerful, life-enhancing outcomes.

Why ferritin blood tests matter at every life stage

• Teens: Heavy or irregular periods combined with growth spurts place enormous demand on iron. Low ferritin here often shows up as fatigue, a pale face, hair loss (part gets wider), anxiety, and poor concentration.
• Women of reproductive age/stage: Monthly blood loss means ongoing iron drain, especially when periods are heavy. Poor iron status including low ferritin contributes to exhaustion, low resilience, PMS symptoms, thyroid struggles and the sense that life feels uphill.
• Pregnancy: Iron needs skyrocket, with around 1000mg required across a full-term pregnancy. Babies born to iron-deficient mothers or prematurely start life at a disadvantage, with lower iron stores themselves.
• Perimenopause: Hormonal changes can trigger flooding or heavier bleeding, rapidly draining iron stores just as the body is already adapting to shifting hormones.
• Post-menopause: While needs are lower, absorption challenges (from gut issues or medications) can still leave ferritin levels suboptimal. Or this can be a time (once menstruation ceases) when a woman finds out she has the genetic iron overload condition called Haemochromatosis, with a blood test being the only way to truly know.

Ferritin – your iron reserves – means that you have enough in the tank to fall back on when daily demands remain consistent or rise and you’re not obtaining or absorbing enough through what you’re eating. Whether an increase in requirements is related to your menstrual cycle, pregnancy, growth spurts, exercise, illness or simply modern life, without those reserves, your body is constantly scraping the bottom of the barrel, leaving you more vulnerable to fatigue, low mood, anxiety, inadequate thyroid hormone production, and poor resilience.

Listening to the whispers

The beauty of paying attention to ferritin is that it helps us hear the body’s whispers before they become screams. If you’ve been told your blood test results are fine but you still feel exhausted, foggy or flat, it’s worth getting your iron studies, including your ferritin levels, tested – and remembering that “normal” does not always mean optimal.

When iron status is restored, women often describe the shift as life-changing. Energy steadies, sleep deepens, mood brightens, resilience returns. It’s not about chasing perfection – it’s about giving your body the resources it needs to thrive.