It’s a chicken and egg question: Does iron deficiency — a condition caused by losing too much iron from your red blood cells — cause heavy periods, or do heavy periods cause iron deficiency? With one-third of women suffering from some form of iron deficiency due to heavy periods, it’s something we are asked about quite often! Let’s dig in:

woman resting a hot water bottle on her lower abdomen

What is iron deficiency? 

Iron deficiency happens when your body has too little iron for your red blood cells to effectively carry oxygen through your body. Iron deficiency is a condition that can seriously interfere with your ability to live your day-to-day life, but is fortunately very treatable through diet and medication.

Women with mild or moderate cases of iron deficiency might experience symptoms like weakness, extreme fatigue, headaches, and brittle nails. More severe cases of iron deficiency can lead to iron deficiency anemia, as well as more serious symptoms like chest pain and cravings for non-food items like ice and dirt, called pica.

According to new research in The Lancet, a leading medical journal, more than a third of women under the age of 50 are iron deficient. We know that women’s pain is often downplayed, and iron deficiency is often underdiagnosed among women with heavy periods. The symptoms of iron deficiency that women experience, like fatigue, are “frequently normalized by society” said Dr. Malcolm Munro, a professor of obstetrics and gynecology, in a study published by the American College of Obstetrics of Gynecology.

What causes iron deficiency? 

There is no single cause of iron deficiency, and iron deficiency can happen in many different stages of your life. Not getting enough iron in your diet, or losing iron through blood loss and pregnancy can all contribute to iron deficiency over time.

Blood loss

Your red blood cells carry iron through the body, so bloss loss due to heavy periods or internal bleeding can lead to iron deficiency. Heavy periods, generally described as periods that last longer than 8 days and require you to change your pad or tampon every hour, are a leading cause of iron deficiency among young women. 

woman shopping for period care products


Your body gets iron from the foods that you eat, like meat, poultry, and leafy greens. Not getting enough iron from your diet can cause iron deficiency. Vegetarians and vegans are more likely to be iron-deficient than those who eat meat, which is why many doctors recommend supplementing a vegetarian diet with plenty of iron-rich foods.


Pregnant women need extra iron in their diet because their bodies are hard at work supplying blood to their fetuses! The World Health Organization recommends iron-containing supplements to pregnant women to support fetal development and reduce the risk of iron deficiency throughout pregnancy.

Does iron deficiency cause heavy periods?

Heavy periods cause your body to lose red blood cells and can lead to iron deficiency in young women. As you lose blood through your period, you also lose your body’s iron stores.

But can iron deficiency make your periods heavier? Some research says yes. Low iron stores can cause heavier and longer periods, leading to a painful cycle of iron deficiency exacerbated by heavy periods. 

How does this happen? According to the journal Obstetrical & Gynecological Survey, iron helps constrict your blood’s capillaries, which in turn slows the flow of your period. Without enough iron stores to do this, your periods might become heavier, leading to further iron loss. 

Iron deficiency is just one cause of heavy periods. Heavy periods might also be caused by hormone conditions like endometriosis, uterine fibroids, or blood clotting disorders, which is why diagnosis from a provider is important if you suspect that you have an iron deficiency. 

How can I find out if I am iron deficient? 

You deserve to feel good and strong. Despite its shocking prevalence among younger women, iron deficiency screenings aren’t regularly included in routine blood work, so it’s important to advocate for yourself to your provider if you suspect that you have an iron deficiency. 

There are also a number of at-home testing options available, some of which even include the option to consult with a nurse if your iron levels are found to be abnormal, so you can start feeling better, faster.

How can you treat iron deficiency? 

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Fortunately, iron deficiency can be easily treated, and many women report feeling better within a few weeks of treatment! If you are found to be iron deficient, your doctor might offer a number of treatment options, including diet changes and medication.


Medications are highly effective treatments for iron deficiency and are often one of the first treatment options your doctor might suggest.

Medications like ACCUFeR, a twice-daily prescription that treats low iron stores in the body, have been found to restore hemoglobin stores to normal levels within 12 weeks of treatment for the majority of patients, with one-third seeing results in just 4 weeks!  

woman picking up iron supplements at the pharmacy

Dietary changes

Changes to your diet can also be effective at treating iron deficiency, and there are iron-rich food options for every diet. These include:

  • Red meat like beef, veal, lamb

  • Leafy greens like kale, spinach, and collard greens

  • Poultry like chicken and turkey

  • Seafood, especially tuna, and sardines (tinned fish date night, anyone?) 

  • Iron-enriched pasta, grains, and cereals

Iron deficiency can make it hard to live your life, but it doesn’t have to. Medication and lifestyle changes are available to help you manage an iron deficiency and start feeling your best again.

Erin Pettis is a Content Marketer and freelance writer based in NYC.