“You don't have low iron, you just can't use it.”
Some version of this shows up on every iron wellness account on my feed, usually right before they tell you to stop taking iron.
When you are endlessly searching for solutions, these words come to haunt you.
Have I been doing it wrong all of these months? Is my iron actually low, or is something else going on? Do I just have no idea what I'm doing?
I find this framing is actually doing a disservice. Yes, it gets our attention. But it swaps the problem a lot of women actually have for the one only some of them do.
Let me explain. There are two possible types of iron deficiency that these accounts are failing to recognize in the same breath. And these two types feel identical.
Same symptoms, because the end result is the same: iron isn’t reaching where your body needs it.
Let me make it more concrete by talking about a often-proposed solution. Lactoferrin often comes up as something that could help with your iron levels.
The catch is that lactoferrin is most relevant in only one of the two scenarios.
Here’s what caught my eye this week:
📄 Chronic anemia was linked to a higher risk of dementia: In ~1 million adults over 60, persistent anemia raised dementia risk in a dose-dependent way (moderate-to-severe anemia HR 1.20). A smaller bump in women (HR 1.07) than men, but one more reason not to let low iron continue for years. (Scientific Reports)
📄 Low vitamin D tracked with worse insulin resistance in PCOS: Across 14 studies and 1,856 women with PCOS, lower vitamin D correlated with higher insulin resistance (r = −0.32), strongest in those who were overweight. Note that it’s association, not proof, but an easy marker to check. (Journal of Obstetrics and Gynaecology Research)
🧴 Clair Health raised $11.6M to build a noninvasive continuous hormone monitor for women: A "CGM for hormones" concept in development, though continuous, noninvasive hormone tracking is unvalidated consumer tech today. No device has been shown to do this accurately, and I expect that we have a fair way to go on the science here. Nonetheless, exciting times for women’s health.
Just sharing here what's new this week. No affiliates, no sponsorships, no freebies. A mention here isn't a recommendation.
Is it low iron, or “stuck” iron? The difference determines whether lactoferrin can help
Lactoferrin is a milk-derived iron-binding protein, not an iron supplement.
It's a first-line immune protein with antibacterial, antiviral, and antifungal activity, with a critical role in calming inflammation and having measurable effects on the gut microbiome.
This is why it's typically sold for immunity as much as iron.
So what does it have to do with iron?
Two different iron problems present as the same symptoms: tired, drained, foggy.
Absolute deficiency (~1 in 3 women) means you're just empty. You don't have enough iron in your body. And the only fix is to get more iron into your body.
Functional deficiency (~1 in 5 women) means you have iron, but it's stuck in storage and can't get out. It can't get into your bloodstream so that you can actually use the iron for your body’s needs. The hormone, hepcidin, controls the lock. When hepcidin is high, iron stays locked in.
And inflammation — the most common culprit — drives hepcidin up.
Where lactoferrin comes in
Lactoferrin’s entire purpose is to calm inflammation. You can see where I'm going with this.
Despite the "fer" in its name, lactoferrin is not an iron pill. An oral dose carries only ~80 µg of iron versus 7-100 mg in an iron supplement, so any effect on iron status runs through its anti-inflammatory action.
Lactoferrin lowers IL-6, which lowers hepcidin, which reopens the ferroportin portals that release iron from storage into your bloodstream.
If you genuinely don’t have enough iron in your body to work with, lactoferrin won't really help you all that much. It won't raise your iron levels out of thin air.
A pooled analysis found lactoferrin raised iron markers while actually lowering how much iron people absorbed (and lowering IL-6).
It’s anti-inflammatory, not reliable iron delivery.
It’s worth saying that what we know for certain about lactoferrin is purely its mechanistic functions in decreasing inflammation. The jump to how it actually impacts our iron levels in the end is still inference at this point in time.
The strongest review to date found insufficient evidence that lactoferrin actually raises iron levels over standard iron pills, and nearly all the data we have is for pregnant women.
“If it works for me, does that mean I’m inflamed?”
No. We can’t necessarily run the logic in the other direction.
“Working” is confounded. One of the likeliest reasons you feel better is that lactoferrin is gentle enough that you actually stay on it and have absorbed dietary iron over those weeks, instead of quitting iron pills, which are notorious for their GI discomfort.
Iron markers (as a show of “working”) also don't tell us exactly what's going on. They can climb even as your absorption falls. If our lab markers reliably tracked back to their mechanisms, we wouldn't have so many troubles with iron, quite frankly.
Ferritin, in particular, is a noisy readout taken alone. It doubles as an inflammation marker, and its standard ranges miss iron deficiency in women.
The medium-good-to-good news is that if you think inflammation might be what's going on, it's measurable. Get CRP, ferritin, and transferrin saturation tests done together.
The undisputed finding
Lactoferrin causes far fewer gut side effects than ferrous sulfate, your standard generic iron supplement.
So yes, while the claim, “You don't have low iron, you just can't use it,” is true for about 1 in 5 women, for 1 in 3, they genuinely don't have enough iron to work with, and no amount of lactoferrin or iron release will fix it.
💊 If you take lactoferrin, add it alongside your iron. Don’t swap it in for iron. A dose carries only ~80 µg of iron, so it can't refill an empty tank. If your stores are genuinely low, dropping iron for lactoferrin leaves the actual problem untreated.
🏷️ Check the label for "bovine lactoferrin" and a dose near the studied one: ~100 mg, twice a day. That's the amount used in the trials.
🧴 If you keep taking lactoferrin, count it as immune and gut support. Its best-evidenced uses are antibacterial and immune. Any effect on iron is still technically unproven. Treat anything lactoferrin does for it as a bonus.
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