Do Iron Supplements Cause Constipation?

There are lots of reasons why you might find yourself taking iron supplements, but ultimately they all lead back to an iron deficiency.

You may have developed an iron deficiency due to a variety of different things, and if changing your diet hasn’t reversed this, then your doctor might recommend taking iron supplements to support your diet. 

Supplements of any type come with possible side effects, and one that people tend to report regarding iron supplements is issues with their bowels.

In particular, some people report suffering with constipation after taking iron supplements. But is this common? Do iron supplements cause constipation?

In this guide, we’re taking a look at whether, or not, iron supplements can cause constipation. So, if you want to find out more, keep on reading! 

What Are Iron Supplements?

First things first, let’s take a look at what iron supplements are. Well, as the name suggests, iron supplements are supplements that you can take to sort out your iron deficiency.

If you suffer with low iron, this is typically due to your diet. But if eating a high-iron diet alone isn’t enough to resolve your iron deficiency, it might be recommended that you take iron supplements instead.

Iron supplements usually come in the form of tablets. While they may be prescribed by your doctor, they are also available to buy across a multitude of different stores.

This is why a lot of people actually end up taking iron supplements without being advised to by their doctor. 

As well as being available in tablet form, you may also come across iron supplements that are in liquid form.

You may find yourself taking either liquid or tablet iron supplements if you have symptoms associated with low iron, or a condition such as anemia.

If you are suffering with the symptoms associated with low iron, you may find yourself unbothered by potential side effects, but do they actually make you constipated? Let’s find out. 

Do Iron Supplements Cause Constipation?

So, iron supplements are designed to increase your iron levels, and compensate for any iron deficiencies. This means that they increase the amount of iron that is inside your body, and this can cause your body to experience some side effects

One of the side effects at the top of this list is constipation. Yes, iron supplements can cause constipation, and this is one of the things that many people report when they first start taking iron supplements.

The sudden change in iron in your system can impact the way that your digestive system works, and this can lead to a variety of different stomach problems. 

Constipation is one of the most commonly reported. This mainly occurs because your body is struggling to absorb the sudden increase of iron that is in your system.

When this happens, a certain amount of iron will remain in your gut, and this can delay your digestive system, causing constipation. 

However, constipation isn’t the only stomach issue that is reported when people start taking iron supplements.

In addition to constipation, some people often experience bouts of diarrhea, cramps, nausea, and heartburn. All of these side effects are connected to your body’s digestive system, and this is the part of the body that is most heavily affected by an influx of iron. 

In addition to these side effects, some people also report a change in their stools when they start taking iron tablets. In particular, they tend to notice a change in the color of their stools, with some people reporting gray or even green stools.

This can be pretty alarming, but please rest assured that it is perfectly normal if you are taking iron supplements.

Why Might You Take Iron Supplements?

As we have established, the main reason why you might find yourself taking iron supplements is if you have an iron deficiency.

You may have an iron deficiency that is caused by your diet, or you might have a health-related iron deficiency, such as anemia. 

If you are aware that you are eating a low-iron diet, then you may decide to take iron supplements to make up for the lack of iron in your own diet. So, this could be something that you decide to take entirely on your own back.

Likewise, if you have experienced symptoms of iron-deficiency, you might speak to your doctor to explore treatment for this, which might result in you being prescribed iron supplements. 

So, as you can see, there are lots of reasons why you might end up taking iron supplements. 

How Do You Stop Constipation When Taking Iron Supplements?

If you need to take iron supplements due to an iron deficiency, it is possible that you might be anxious about the potential side effects associated with this. Digestive issues are not pleasant, and they can really impact your day-to-day life.

So is it possible to stop constipation when taking iron supplements?

If you are experiencing issues with constipation while taking prescribed iron supplements, then it is worth speaking to your doctor regarding this. They may suggest reducing the amount of iron that you are taking to see if this combats your constipation. 

But if it isn’t possible to reduce the amount of iron that you are taking, then there are other ways to prevent constipation when taking iron supplements.

This does include taking an additional supplement to help your digestive system while also taking your iron supplements. This supplement will soften your stools, ensuring that you do not feel constipated. 

There are a couple of different stool softening supplements that you may take, including docusate sodium.

So, speak to your doctor if you are struggling with constipation due to iron supplements, and they should be able to point you in the right direction.


In short, yes, iron supplements can cause constipation. Taking iron supplements has been connected with a wide range of different stomach problems, including nausea, diarrhea and heartburn, as well as constipation.

But, thankfully, these issues can be resolved! Thanks for reading.