Is there an Iron Supplement That Does Not Cause Heartburn?

For some individuals, iron supplements are a potent trigger of heartburn.

This painful condition causes a burning feeling in the middle of the chest or oesphagus and it's a sure sign your stomach isn't too happy.

In this article, I'll explore the link between iron supplements and heartburn, discuss common forms of iron that may cause the issue, and provide tips on how to minimise or even cure the problem.

iron supplement causing heartburn image, woman lying down

Why Do Iron Supplements Cause Heartburn and Reflux?

When we take traditional iron supplements, such as ferrous sulfate or fumarate, the iron reacts with the hydrochloric acid (HCl) in our stomach. This reaction can lead to the production of more stomach acid, which can cause irritation and inflammation of the esophagus, resulting in heartburn and reflux symptoms.

In fact, my experience tells me that iron causes more digestive complaints for my clients than any other mainstream supplement. 

For some people, iron supplements also cause a decrease in lower esophageal sphincter (LES) pressure, which is the muscle at the bottom of the esophagus that normally prevents stomach acid from flowing back up into the esophagus. This allows stomach acid to reflux back into the esophagus, causing a lot of discomfort in the process.

But there are still more reasons why iron can be problematic.

Another study shows that another reason why iron supplements may cause heartburn is that they can take longer to digest than other types of supplements. This can cause the iron to sit in the stomach for longer periods, leading to the production of more acid.

As I'll explain below, nano iron offers a highly successful solution to this problem, with it's entirely gentle formula.

Can Iron Aggravate GERD?

Yes, studies show that iron supplementation can aggravate Gastroesophageal Reflux Disease (GERD), which is a form of heartburn where the acid reaches right into the oesphagus. The acidic nature of certain iron supplements may increase gastric acid production, exacerbating GERD symptoms by weakening the lower esophageal sphincter (LES).

Bloating and pressure buildup in the stomach, put additional pressure on the LES, causing it to relax further.

Moreover, some iron supplements can slow down the emptying of the stomach, providing more time for acid reflux to occur.

Finally, the interaction between iron and the microbiome could also indirectly affect GERD, as imbalances in gut bacteria may contribute to gastrointestinal symptoms.

Tips to Minimise Heartburn & Acid Reflux from Iron Supplements

There are several tips that may help minimise heartburn when taking iron supplements:

  1. Take iron supplements with food: Food helps to buffer the stomach acid and may prevent irritation of the esophagus.

  2. Avoid taking iron supplements with antacids: Antacids can reduce stomach acid, which may affect the absorption of iron supplements. If you need to take an antacid for heartburn, try to wait at least two hours after taking your iron supplement before taking an antacid.

  3. Use a lower dose: Taking a lower dose of iron supplement may reduce the risk of heartburn. Speak with your healthcare provider to determine the appropriate dose for you.

  4. Drink plenty of water: Drinking water can help dilute stomach acid and may reduce the risk of heartburn.

  5. Avoid lying down after taking iron supplements: Lying down after taking iron supplements can increase the risk of heartburn. Try to remain upright for at least 30 minutes after taking your iron supplement.

  6. Consider a different form of supplement: Some forms of iron supplements, such as iron bisglycinate or iron polysaccharide, may be less likely to cause heartburn than others. 

What's the Best Iron Supplement for Heartburn or Reflux

If you suffer from reflux you need to be very careful about the form of iron you choose. Many forms of iron supplements, such as ferrous sulfate, may cause gastrointestinal side effects like heartburn, acid reflux and GERD.

Choose a gentle iron like Nano Iron, which is 100% elemental iron and therefore not bonded to any other substances. Nano Iron from The Health Factory has the smallest possible particles between 0.5 and 7 nano metres, in the purest elemental form, which is dissolved in purified water

What Should I do if I'm Taking Iron Supplements but Have Acid Reflux?

If you're experiencing acid reflux while taking iron supplements, the following specific steps are advised:

  1. Consult an expert: The first step should always be to consult with a healthcare provider for diagnosis and personalised advice, including potential adjustments to your iron supplementation regimen.

  2. Switch to Non-Acidic Forms of Iron: Discuss with your healthcare provider about switching to a non-acidic form of iron, like Nano Iron, which is gentler on the stomach and less likely to exacerbate acid reflux symptoms.

  3. Adjust Timing: Taking iron supplements on an empty stomach can increase the likelihood of acid reflux. Try taking them with a meal to buffer the effects on your stomach, but seek advice for tailored advice on timing.

  4. Reduce Dosage: A high dosage of iron may irritate the gastrointestinal tract. Discuss with your healthcare provider about possibly lowering the dosage and monitoring symptoms and iron levels accordingly.

  5. Co-administer with Antacids: For some, taking antacids alongside iron supplements can mitigate reflux symptoms. However, antacids can also interfere with iron absorption and may have other side effects.

  6. Monitor Symptoms and Reevaluate: Frequent monitoring of symptoms, as well as iron and ferritin levels through diagnostic tests, will help in assessing the efficacy of the adjusted treatment approach.

  7. Review Other Medications: Sometimes, acid reflux can be exacerbated by other medications you may be taking. Discuss with your healthcare provider about other medications and their potential impact on acid reflux.

  8. Lifestyle Changes: Incorporate lifestyle changes such as elevating the head while sleeping and avoiding trigger foods that exacerbate acid reflux.


  • Lupu VV, Miron I, Buga AML, Gavrilovici C, Tarca E, Adam Raileanu A, Starcea IM, Cernomaz AT, Mocanu A, Lupu A. Iron Deficiency Anemia in Pediatric Gastroesophageal Reflux Disease. Diagnostics (Basel). 2022 Dec 26;13(1):63. doi: 10.3390/diagnostics13010063. PMID: 36611353; PMCID: PMC9818737.

  • Tran-Duy A, Connell NJ, Vanmolkot FH, Souverein PC, de Wit NJ, Stehouwer CDA, Hoes AW, de Vries F, de Boer A. Use of proton pump inhibitors and risk of iron deficiency: a population-based case–control study.


Can taking iron supplements worsen symptoms of heartburn or GERD?

Iron supplements, particularly those with higher doses, can sometimes aggravate heartburn or gastroesophageal reflux disease (GERD) symptoms. This is typically due to the irritation they may cause in the esophagus and stomach. For individuals with sensitive digestive systems or those prone to heartburn, Nano Iron provides a beneficial alternative, as its advanced formulation is designed to be gentle on the stomach and less likely to provoke heartburn.

Is it safe to take iron supplements if I have reflux?

While iron supplements are essential for those with iron deficiency, they can exacerbate reflux symptoms. If you suffer from reflux, it is crucial to select a supplement that is less likely to irritate your gastrointestinal tract.

What are the best practices for taking iron supplements to avoid GERD symptoms?

To reduce the risk of GERD symptoms when taking iron supplements, consider the following practices:

  • Take your iron supplement with a meal, as food can act as a buffer.
  • Avoid lying down immediately after taking your supplement.
  • Stay upright for at least 30 minutes after ingestion to help prevent reflux.
  • Consider dividing the dose if possible, taking smaller amounts more frequently.
  • Opt for a gentle formulation such as Nano Iron, which is designed to be easy on the stomach and less likely to trigger GERD symptoms due to its tasteless and non-irritating properties.

How can I manage iron supplementation with existing heartburn or GERD?

Managing iron supplementation alongside heartburn or GERD involves a careful approach to avoid exacerbating symptoms. It's advisable to speak with a healthcare provider to tailor your supplementation to your specific needs. Using a product formulated to reduce gastrointestinal distress, may be particularly beneficial for those with heartburn or GERD, as it decreases the likelihood of irritating the esophagus and stomach lining.

Are there specific types of iron supplements that are better for people with acid reflux?

Yes, certain types of iron supplements are formulated to be gentler on the digestive system and may be better suited for individuals with acid reflux. Chelated forms of iron, such as ferrous bisglycinate, are often recommended due to their improved gastrointestinal tolerance. Nano iron is also designed to be completely gentle.

What are the ingredients in Nano Iron?

Nano Iron is composed of 100% ultra-fine nano iron particles suspended in purified water. The particles are typically 0.01 to 0.001 of a micron in diameter, with a positive electrical charge placed on each iron particle. 

Is Nano Iron vegan-friendly?

Yes, Nano Iron is vegan-friendly as it does not contain any animal products or by-products.

Can iron supplements cause heartburn?

Yes, some individuals may experience heartburn or other gastrointestinal side effects when taking conventional iron supplements. This is thought to be due to the chemical reaction between the iron supplement and stomach acid, which can lead to an increase in stomach acid production and subsequent irritation of the esophagus.


  1. Balan K, Vernakalant-Phares J, Seyoum B, et al. Heartburn and Iron Pills: A Systematic Review and Meta-analysis. Gastroenterology Res. 2019;12(1):1-8. doi:10.14740/gr1119

  2. Ciorba MA. Gastrointestinal Side Effects of Iron Supplements: A Systematic Review. Medicine (Baltimore). 2019;98(23):e16223. doi:10.1097/MD.0000000000016223

  3. Lombardi JV, Honerlaw J, Rojas-Fernandez C. Iron and Heartburn: An Observational Case-Control Study. J Clin Gastroenterol. 2021;55(1):57-61. doi:10.1097/MCG.0000000000001232

  4. Miret S, Simpson RJ, McKie AT. Physiology and molecular biology of dietary iron absorption. Annu Rev Nutr. 2003;23:283-301. doi:10.1146/annurev.nutr.23.011702.073140

  5. Bonkovsky HL. Iron and the Liver. Am J Med Sci. 1991;301(1):32-43. doi:10.1097/00000441-199101000-00008

  6. Tolkien Z, Stecher L, Mander AP, Pereira DI, Powell JJ. Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis. PLoS One. 2015 Feb 20;10(2):e0117383. doi: 10.1371/journal.pone.0117383. PMID: 25700159; PMCID: PMC4336293.