Female hormonal health and iron: what a new review says about hormones and hepcidin

A heavy week, and a tired body

It is one of the heavy days of your period. You took the stairs at work and arrived at the top more out of breath than you expected. In the afternoon your head feels slow, and in the evening the sofa wins every argument. Later in the month, the same stairs feel normal again. You start to wonder whether you are imagining the pattern, or whether something in your body, such as your iron or your hormones, really rises and falls with your cycle: a question about female hormonal health that a new review article has something to say about, with the iron hormone hepcidin in the leading role.

The question is older than it seems. Every month blood leaves the body, and iron goes with it.⁠² Yet the interplay between iron and the monthly cycle has had less attention than you might expect. This long read follows a new review that brings the pieces together. The review is clear about what is known, and just as clear about what is not.

Not a rare question

We would like to open with a count of how many women live with low iron before the menopause. The verified sources behind this article do not contain an official figure like that, so we give none rather than guess. What the sources do show is that GPs do not see this as an unusual question, but as an everyday one.

Thuisarts, the patient website of the Nederlands Huisartsen Genootschap (the Dutch college of GPs), has a page for exactly this situation: losing a lot of blood during your period. The page gives two reasons to make an appointment with your GP: the bleeding itself bothers you, or you tire easily.⁠³ The NHS in the United Kingdom points the same way and explains how a GP usually checks: with a blood test that shows whether your red blood cell count is normal.⁠⁴ When two national health services each write a page about the same ordinary situation, a lot of people are in that situation with you.

This longread is about the years with a monthly cycle. For the years after that, our page on how long the menopause lasts brings together the figures.

Why iron and your cycle are linked

How much iron from your food gets into your blood is not left to chance. The amount is controlled by hepcidin, a hormone made by the liver. The review article calls the hepcidin system the master regulator of how much iron moves through the body.⁠¹ When hepcidin is high, less iron gets through. When hepcidin is low, more gets through.

In women before menopause, a second layer sits on top of that system. The female sex hormones estradiol and progesterone act directly on how much hepcidin the liver makes. According to the review, this lays a predictable monthly rhythm over the iron your body already has to work with.⁠¹ Laboratory research has pointed this way for more than a decade, mainly in liver cells and in mice.⁠⁵

Where the knowledge ran out

What was missing was the step from the lab to an ordinary month. Knowing that a hormone moves hepcidin in a dish does not tell you what happens in a woman over four weeks, while several hormones rise and fall at the same time. Studies that took blood from the same women again and again during the cycle saw hepcidin and iron fall during menstruation and then rise again.⁠⁶ Whether that matched what the hormone mechanism predicts had not yet been clearly worked out. You really do feel the tiredness on a heavy day. The explanation behind it was still in pieces.

When your cycle stops, this question changes. You can read which symptoms belong to that later phase, and how long they last, in menopause symptoms: which ones are part of it and how long they last.

A review article from Perth

The new piece comes from four researchers: D. Balakirishnan, F. Dukovski, H. Bytheway and C. Dugan, all affiliated with the School of Medicine at the University of Western Australia in Perth. C. Dugan is also affiliated with the Pennington Biomedical Research Center of the Louisiana State University System in Baton Rouge, USA, and with the School of Population Health at Curtin University in Perth. Their article, “Cyclical Iron Homeostasis: The Role of Sex Hormones in Female Iron Regulation”, was published on 18 September 2026 in the journal Frontiers in bioscience (Landmark edition).⁠¹

It is a review article: an article in a scientific journal, not a preprint, that brings existing research together and does not run a new trial or group study of its own. The authors set out to do four things. The article summarises how estradiol and progesterone act on hepcidin. It maps that action onto the menstrual cycle to see what it predicts. It tests that prediction against what has actually been measured in women. And it proposes a new way to sort low iron by what is going wrong underneath.⁠¹

Why does this matter for you? If your iron has ever been checked, or ever will be, the result depends partly on where you were in your cycle that day. Iron levels in the blood move with the phase of the cycle, so a single blood test on its own can give a misleading picture.⁠¹ This review explains why that happens, and is honest that the full story over a whole month is not yet known. That honesty is useful: you know which questions to ask, and which confident claims to be careful with.

One gatekeeper, pulled two ways

There is one idea worth taking away from this review article. Your iron supply has a gatekeeper, and two of your own hormones pull that gatekeeper in opposite directions.

The gatekeeper is hepcidin. Estradiol, the main oestrogen before menopause, generally pushes hepcidin down. It does this through the oestrogen receptor, by acting on HAMP, the gene that carries the instructions for making hepcidin.⁠¹ A 2012 study in liver cells and in mice traced this to a small part of the gene’s control region that responds to oestrogen.⁠⁵ That was not research in people, but in the lab and in animals.

Still, the picture is less tidy than that. In mice without ovaries and in liver cell lines, estradiol also pushed hepcidin up, through a different receptor (GPR30, also called GPER1) and a signal called BMP6.⁠⁷ So one hormone seems to have two routes with opposite effects, and which route wins in a living woman’s body is not settled.

Progesterone pushes the other way. Given from outside the body, progesterone raises hepcidin in women.⁠¹ A 2016 chemical screen found steroid molecules, including progesterone, that raise hepcidin through a protein called PGRMC1. Raised hepcidin was seen in mice and in people who were given the hormone.⁠⁸

Put these effects on a calendar and you get a neat prediction. In the first half of the cycle, the gate should open wider, so taking up iron should be easier. In the second half, the gate should narrow, so taking up iron should be harder. Late in the cycle, hepcidin should reach its highest point.⁠¹ On paper, it is a clear story. The question is whether the body follows it.

Two examples from real bodies

Take women going through IVF. As part of that treatment, their own oestrogen production is strongly stimulated. In that situation, hepcidin in the blood fell clearly.⁠⁹ This is one of the clearest signs in people, not just in cells or in mice, that the body’s own oestrogen can lower the gatekeeper.

Now take an ordinary month. In a study that followed ninety healthy women through the cycle, both hepcidin and iron fell during menstruation and then rose again afterwards.⁠⁶ Picture two blood tests for the same person: one on a heavy day of their period, one a few days later. The two results can differ because of the timing alone. That is why the review warns that a single blood test can mislead.⁠¹ Claire Badenhorst, who researches iron in women, draws the practical conclusion for doctors.⁠¹⁰

The research shows fluctuations in iron status during a woman’s monthly cycle, and on that basis we would advise doctors to note which phase of the menstrual cycle a woman is in when blood is taken to check iron.

Claire Badenhorst, Lecturer, Massey University, New Zealand

What the review showed, and in whom

The review article is about women before the menopause. As a review article, it has no group of participants of its own. The abstract does not report how many studies or how many women the authors used, so that number is not given here either.⁠¹

The most important thing the article shows is a gap between prediction and measurement. The hormone mechanism predicts a peak in hepcidin late in the cycle. In groups of women who had blood taken repeatedly during the cycle, that peak is not visible. Interleukin-6, a messenger substance of the immune system that the review article also looked at, does not rise in the second half of the cycle either. The authors call what the hormone mechanism means across a whole cycle the central open question.⁠¹

The review article also proposes sorting low iron by what lies beneath it. Sometimes the stores are empty. Sometimes there is iron, but the iron does not reach where it is needed. And sometimes the production of blood cells itself is held back. The authors argue that a shift with the cycle means something different in each of these three situations.⁠¹

The subject was slow to get this kind of attention. Hans Verhoef, a nutrition researcher in Wageningen, put it bluntly: if men had this problem, it would have been studied long ago.⁠²

If men had this problem, it would have been studied long ago

Hans Verhoef, Associate Professor of Human Nutrition and Health, Wageningen University & Research

What the review did not show

This review article brings no new measurements. Much of the hormone mechanism the article describes comes from liver cells and animals, not from women going through a normal month.⁠¹ The neat monthly swing the article predicts does not clearly show up in the women who were actually measured. Sorting low iron into three types is a proposal that still has to be tested in practice. Timing iron supplements to the cycle is presented only as a biologically plausible idea that needs thorough testing in future studies, not as something anyone should act on now.⁠¹ One more limitation lies with us: BioProfile has not read the full text of the article, only the abstract.

What you can do with this for your female hormonal health

If your blood is tested for iron, write down which day of your cycle it is and mention it to your doctor. The most important practical point of the review is that iron levels move with the cycle, and a doctor reads a result better when they know when the blood was taken.⁠^1,10

If heavy blood loss during your period bothers you, or if you get tired easily, make an appointment with your GP. That is the advice of both Thuisarts and the NHS, and the usual check is a blood test.⁠^3,4

No review article can tell you how your own hormones move through your month. A simple first step is to look at where your hormonal balance stands today, and the scan below starts there. The scan is not a diagnosis. The scan shows you where you are starting from.