The Iron Connection: Ferritin and Metabolic Health in Menopause
If you've been told your labs are normal but you're still gaining weight, exhausted, and struggling through perimenopause or menopause — your ferritin might be part of the story nobody has looked at closely enough.
What ferritin actually is
Ferritin is the protein your body uses to store iron. When your cells need iron, they draw from these stores. A serum ferritin test tells us how replete — or depleted — those reserves are.
Iron is required for oxygen transport, mitochondrial energy production, thyroid hormone synthesis, dopamine and serotonin production, and immune function. When ferritin is low, your body begins rationing iron across every system that depends on it — and that is most of them.
The problem with "normal"
Standard lab reference ranges for ferritin are broad, with lower limits as low as 12 µg/L in some labs. A woman with a ferritin of 14 µg/L will be told she's normal. But research consistently shows that symptoms of iron insufficiency — fatigue, hair loss, cognitive difficulty — begin appearing when ferritin falls below 50 µg/L. ¹ Many clinicians working in this space consider 70–100 µg/L closer to optimal for symptom resolution, particularly in the context of the hormonal demands of perimenopause.
A normal result and an optimal result are not the same thing.
Why perimenopause changes the picture
Estrogen plays a role in iron regulation and absorption, and the years leading up to menopause are metabolically turbulent. Several things can converge to make ferritin status particularly vulnerable during this time.
Many women experience heavier or more irregular periods in perimenopause — a direct consequence of fluctuating progesterone and estrogen. More blood loss means more iron loss. Women who have been managing fine for years can find their ferritin dropping significantly as periods become unpredictable.
Gut absorption also shifts. Reduced stomach acid — more common as we age — impairs the conversion of dietary iron into its absorbable form. And the hormonal recalibration of perimenopause places greater demand on mitochondrial, metabolic, and neurological systems — all of which run on iron.
After menopause, the picture changes again
Once periods stop, the ongoing blood loss that has been depleting iron for decades finally ends. Many postmenopausal women see ferritin rise — but that isn't always a straightforward improvement.
Ferritin above 200 µg/L in postmenopausal women has been associated with increased inflammation, insulin resistance, non-alcoholic fatty liver disease, and cardiovascular risk. ² It is also a screening marker for hereditary hemochromatosis, a genetic iron overload condition that more commonly becomes symptomatic in women after menopause, when the protective effect of menstruation is lost.
It's also important to understand that ferritin is an acute phase reactant — it rises in response to inflammation and metabolic dysfunction, independently of iron stores. ³ Elevated ferritin doesn't automatically mean iron overload; it may be signaling chronic low-grade inflammation, which is itself a key driver of metabolic disease in the menopause years.
Some postmenopausal women also remain depleted — particularly those who began the transition with low stores, have absorption issues, follow a plant-based diet, or have underlying gut conditions.
The metabolic connection
This is where the science becomes particularly relevant for women dealing with weight gain, fatigue, and metabolic struggles that feel disproportionate to what they're eating and how they're moving.
Iron plays a direct role in pancreatic beta-cell function — the cells that produce insulin. Both deficiency and excess can impair insulin secretion and worsen insulin sensitivity. ⁴ Women already navigating the metabolic shifts of declining estrogen are particularly vulnerable to this disruption. Low ferritin also shifts metabolism toward less efficient glycolytic pathways, meaning the body struggles with fat oxidation and loses metabolic flexibility — contributing to weight that feels impossible to shift.
Iron-sulfur clusters are structural components of the mitochondrial electron transport chain — the machinery that generates ATP, your body's energy currency. Depleted ferritin means impaired mitochondrial function, which presents as the deep, unrelenting fatigue that is so commonly reported in this life stage and so frequently dismissed. ⁵
Iron is also required for thyroid peroxidase, the enzyme responsible for producing thyroid hormones. Low ferritin can impair thyroid hormone synthesis and the conversion of T4 to active T3 — even when thyroid tests appear normal. ⁶ Many women in perimenopause are treated for hypothyroid-like symptoms when the underlying issue is unaddressed iron insufficiency.
What a complete assessment looks like
Ferritin alone doesn't tell the full story. At KCH, we look at the full iron panel — serum ferritin, serum iron, transferrin saturation, and TIBC — alongside a full blood count, inflammatory markers like CRP, thyroid function including free T3, fasting glucose and insulin, liver function, and a hormonal panel where relevant.
The numbers are only part of the picture. A thorough symptom and dietary history matters just as much.
What treatment actually looks like
Dietary optimization is always the starting point. Heme iron from red meat, poultry, and fish is the most bioavailable form. Non-heme iron from legumes, tofu, and dark leafy greens is less efficiently absorbed but can be meaningfully enhanced by pairing it with vitamin C — and significantly inhibited by tea, coffee, and calcium consumed at the same meal.
For women with ferritin below 50 µg/L and symptomatic iron insufficiency, oral supplementation is often appropriate. Ferrous bisglycinate tends to be better tolerated and better absorbed than ferrous sulfate. Recent evidence suggests that alternate-day dosing may actually improve absorption by avoiding the hepcidin rebound that occurs with daily supplementation. ⁷
Intravenous iron is an option for women with very low ferritin, confirmed iron-deficiency anemia, or poor tolerance to oral forms. It replenishes stores rapidly and can be genuinely transformative for women who have been struggling for years.
For elevated ferritin, the approach depends on whether it reflects inflammation or true iron overload. If hemochromatosis is identified, therapeutic phlebotomy is the standard treatment. If it's primarily inflammatory, addressing the underlying metabolic drivers — insulin resistance, adiposity, gut health — is the priority.
A note on self-supplementing
Iron is one of the few nutrients where both deficiency and excess cause harm. Supplementing when ferritin is already elevated can worsen metabolic and cardiovascular risk. If you recognize yourself in this post, the most useful step you can take is getting properly tested — not reaching for iron tablets without knowing where your levels actually sit.
If you're in the perimenopause or menopause transition and feel like fatigue, weight changes, or metabolic struggles aren't being fully explained by your current workup, a comprehensive ferritin and iron panel is a reasonable place to look. It's a small test that is frequently overlooked and can change the whole clinical picture.
This content is for educational purposes only and is not intended as medical advice. Please consult a qualified healthcare provider before making any changes to your treatment or supplementation.
References
Verdon F, et al. Iron supplementation for unexplained fatigue in non-anaemic women: randomised double blind placebo controlled trial. BMJ. 2003;326(7399):1124. https://doi.org/10.1136/bmj.326.7399.1124
Shi Z, et al. Serum ferritin and the risk of metabolic syndrome and type 2 diabetes. J Clin Endocrinol Metab. 2015;100(12):4498–4507. https://doi.org/10.1210/jc.2015-2712
Wang W, Knovich MA, Coffman LG, Torti FM, Torti SV. Serum ferritin: past, present and future. Biochim Biophys Acta. 2010;1800(8):760–769. https://doi.org/10.1016/j.bbagen.2010.03.011
Kowluru A. Iron and pancreatic beta-cell function: new insights and new questions. Nutrients. 2020;12(10):3113. https://doi.org/10.3390/nu12103113
Richardson DR, et al. Mitochondrial iron trafficking and the integration of iron metabolism between the mitochondrion and cytosol. Proc Natl Acad Sci USA. 2010;107(24):10775–10782. https://doi.org/10.1073/pnas.0912925107
Beard JL, Borel MJ, Derr J. Impaired thermoregulation and thyroid function in iron-deficiency anemia. Am J Clin Nutr. 1990;52(5):813–819. https://doi.org/10.1093/ajcn/52.5.813
Moretti D, et al. Oral iron supplements increase hepcidin and decrease iron absorption from daily or twice-daily doses in iron-depleted young women. Blood. 2015;126(17):1981–1989. https://doi.org/10.1182/blood-2015-05-642223
