Written by Steve Theunissen | ISSA: CPT & Fitness Nutrition
Fact checked by Robert Iafelice, MS, RD, LDN
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Iron is a mineral that our bodies need but cannot produce. As a result, we need to get it through our diet. The body needs iron to make hemoglobin, a protein found in red blood cells that moves oxygen from the lungs to other regions of the body. Myoglobin, a protein that transports oxygen in muscles, also needs iron for its production.
Iron deficiency is quite common, especially in women, children, and people who follow a vegan or vegetarian diet. Taking an iron supplement can help fortify your intake of this essential mineral, boosting your energy levels, improving athletic performance, and supporting healthy red blood cells.
In this article, we review the seven best iron supplements on the current market, separated by category. We'll also highlight the research-backed benefits of taking an iron supplement and provide you with a comprehensive buyer's guide to help you get the best iron supplement to meet your unique situation.
7 Best Iron Supplements
- Overall Best: Thorne Iron Bisglycinate
- Best Budget: Nature Made Iron
- Best Absorbability: Elm & Rye Iron
- Best For Pregnancy: Life Extension Prenatal Advantage
- Best For Women: Ritual For Women 18+
- Best For Anemia: Klean Iron
- Best Liquid: NOW Liquid Iron
SFS Pick
Thorne
SFS Budget Pick
Nature Made
SFS Absorbability Pick
Elm & Rye
1. Overall Best Iron Supplement: Thorne Iron Bisglycinate
Thorne Iron Bisglycinate provides you with 139% of the DV for iron in the form of iron bisglycinate chelate. This is a form of iron that the body is able to very easily digest and absorb. Studies have also shown that this form is less likely to cause digestive problems than the more commonly used ferrous sulfate.
Thorne Iron Bisglycinate is recommended by many doctors for the treatment of anemia, and there are a lot of customer reviews attesting to its effectiveness in that regard. This supplement has been NSF Certified for Sport, so athletes can be assured that it contains no banned substances.
Iron is the only ingredient in this supplement, so you don't have to worry about artificial preservatives or fillers. Thorne Iron Bisglycinate is gluten-free but not vegan-friendly.
Pros
- Highly absorbable form of iron
- NSF Certified for Sport
- No artificial ingredients
Cons
- Not vegan friendly
Iron Bisglycinate provides an optimal way to supplement iron, which is essential for red blood cell formation. It helps fight fatigue and other symptoms of iron deficiency in athletes and others. NSF Certified for Sport...
2. Best Budget Iron Supplement: Nature Made Iron
Nature Made Iron provides you with three times as much iron per capsule as Thorne Iron Bisglycinate, with 65 mg. The form of iron used here is ferrous sulfate, which has a high solubility rate, allowing the sulfate ions to quickly enter the bloodstream. However, ferrous sulfate is more likely to cause stomach upset than other forms.
Nature Made iron is third-party tested by United States Pharmacopeia (USP) for purity and potency. The supplement comes in a 180-count container, with a recommended daily dosage of one tablet, which gives you a 6-month supply. At a little over ten dollars per container, that works out to be excellent value for money.
Pros
- Excellent value
- 65 mg ferrous sulfate per tablet
- 3rd party tested
Cons
- It may cause stomach upset
Nature Made® Iron provides 65 mg iron to help those who lack in iron meet their nutritional needs. Iron is an essential part of hemoglobin, the protein substance which enables red blood cells...
3. Best Absorbability Iron Supplement: Elm & Rye Iron
Elm & Rye Iron is marketed as a vegan-friendly, non-constipating, and easy-to-digest formula specifically for women. It contains ferrous bisglycinate, a chelated form of iron that is designed to be highly absorbable and gentle on the digestive system.
According to the product label, each serving of Elm & Rye Iron Supplement provides 18 mg of elemental iron, which is 100% of the recommended daily value for adult women. The supplement also contains vitamin C to support iron absorption, as well as other nutrients like vitamin B12 and folic acid.
Elm & Rye Iron Supplement is manufactured in the United States in a GMP-certified facility. The company states that its supplements are independently tested for quality and purity and are free of common allergens like soy, gluten, and dairy.
Pros
- Highly absorbable
- 100% of RDA for women
- 3rd party tested
Cons
- Expensive
Iron supplements can help reverse an iron deficiency when dietary changes alone are unsuccessful. Certain people, including pregnant women, infants, young children, heavy exercisers, and those with certain...
4. Best Iron Supplement For Pregnancy: Life Extension Prenatal Advantage
Life Extension Prenatal Advantage is designed to provide for the special nutritional needs of expectant mothers. As well as 27 mg of ferrous fumarate iron, you get the following vitamins and minerals:
- Vitamins A, C, D3, E, K, B1, B2,B6, b12
- Folate
- Biotin
- Pantothenic Acid
- Iodine
- Zinc
- Selenium
- Copper
- Manganese
- Chromium
- Molybdenum
- Choline
- Potassium
- DHA
- Marigold Extract
These compounds deliver a broad range of benefits for pregnant women, lactating mothers as well as the developing child. Most of the ingredients are dosed at 100% or more of the RDA. The recommended dosage is four soft gel capsules per day.
Life Extension Prenatal Advantage is manufactured in a GMP-compliant facility. There are no artificial flavors, fillers, or preservatives in the supplement, and it is soy, dairy, and gluten-free.
We recommend that pregnant or lactating women check with their healthcare provider before taking this or any other supplement.
Pros
- Complete nutritional profile to meet the needs of pregnant and lactating women
- 27 mg of ferrous fumarate iron per serving
- Softgel capsules
Cons
- Requires taking four capsules per day
This prenatal nutrition is a science-based supplement with today’s recommended dosages of vitamins and minerals, plus nutrients like DHA omega-3, choline, lutein and zeaxanthin for both mom and baby...
5. Best Iron Supplement For Women: Ritual For Women 18+
Ritual For Women 18+ is a multivitamin supplement that has been specifically created to provide for the nutritional needs of women aged 18-40. There are nine key ingredients in this supplement, including folate, omega-3 DHA, vitamin B12, vitamin D, and vitamin K2. This combination will benefit your brain health, make your bones stronger and promote red blood cell formation.
There is also 8 mg of ferrous bisglycinate iron. This is a highly bioavailable form of iron that quickly gets into the bloodstream. This form is also less likely to cause gastric upset than other forms like ferrous sulfate.
Ritual for Women 18+ is available as a one-off purchase or on a subscription basis. Subscribers benefit from free shipping, dollar savings on every purchase, and a money-back guarantee.
Pros
- Nine key vitamins for women
- Highly absorbable ferrous bisglycinate iron
- Vegan-friendly and gluten-free
Cons
- Less than the RDA for iron for women
Ritual For Women 18+ has been specially designed to meet the dietary needs of women ages 18-49. Delivered by the patented beadlet-in-oil capsules, this multivitamin gets absorbed in the small...
6. Best Iron Supplement For Anemia: Klean Iron
Klean Iron from Klean Athlete provides you with 27 mg of iron in the form of iron carbonyl. This form is more purified than most other forms, making it easily digestible. It's also less likely to cause stomach discomfort.
This supplement is marketed as a way for athletes to improve their performance by increasing muscle strength and energy output. It is also designed to improve brain functioning and promote better sleep. However, it has also proven to be successful in helping many people overcome the symptoms of anemia, including fatigue, weakness, and lightheadedness.
The GMP-certified facility where Klean Iron is made conducts quality and purity checks on every batch. This dietary supplement is made without artificial ingredients or common allergens.
Pros
- Designed to meet the needs of athletes
- 27 mg iron per serving
- Highly digestible iron carbonyl
Cons
- Does not contain vitamin C
Optimal iron levels in athletes have been associated with muscle strength and athletic performance, in addition to supporting cognitive function & healthy sleep. Klean Iron supplies 27 mg of iron...
7. Best Liquid Iron Supplement: NOW Liquid Iron
NOW Liquid Iron is marketed as an iron supplement that is simple to digest and absorbable and can support normal iron levels in the body. People who have trouble swallowing pills or capsules may find the liquid form of the supplement to be more convenient.
There are 18 mg of iron in this supplement in the form of ferrochel iron bisglycinate. It is free of major allergens like gluten, soy, and dairy and has no artificial sweeteners or flavors.
NOW Liquid iron has a pleasant fruit punch flavor. It doesn't have the strong iron aftertaste that you get with most liquid iron supplements.
Pros
- Liquid form for easier digestibility
- Pleasant fruit punch flavor
- 18 mg iron per serving
Cons
- Some reviewers note that the cap is hard to get off
NOW uses Iron Taste Free Ferric Glycinate, which has clinically demonstrated superior absorption and is well tolerated because it is gentle and non-constipating...
What is an iron supplement?
Iron supplements are nutritional supplements that contain the mineral iron to address an iron deficiency. They come in many forms, including capsules, pills, liquid, and chewable tablets. Iron supplements may include other compounds, such as vitamin C, to enhance the absorbency of iron.
Benefits of taking iron supplements:
Here are the four main benefits of taking an iron supplement that have been identified by clinical studies:
1. Reduce Anemia
Anemia is a condition where there are fewer red blood cells or less hemoglobin in the blood, which can lead to less oxygen being delivered to the body's tissues and organs. Since the body needs iron to generate hemoglobin, iron deficiency is a frequent cause of anemia.
Iron supplements work by upping the amount of iron in the body, which can help support the production of hemoglobin and reduce the symptoms of anemia.¹
2. Improve fatigue
If iron deficiency anemia is the source of exhaustion, taking an iron supplement may be able to reduce it. Hemoglobin, a protein found in red blood cells that transfers oxygen from the lungs to the body's tissues and organs, is produced only when iron is present in the body. A lack of iron may prevent the body from producing enough hemoglobin, which could lead to decreased oxygen supply and a sense of weakness and exhaustion.
The production of hemoglobin can be assisted by iron supplementation, which can enhance oxygen transport to body tissues and lessen sensations of exhaustion. It should be noted, though, the body can get harmed by iron toxicity if iron supplements are used when they are not necessary. It is important to remember that not all fatigue is due to iron insufficiency.²
If you are feeling constantly fatigued, we recommend speaking with a healthcare professional because there may be other underlying issues that need to be resolved. A healthcare professional can undertake tests to identify any conditions, such as an iron deficiency, that may be causing your fatigue and can advise you on whether iron supplementation is required.
3. May improve athletic performance
Athletes who are iron deficient may benefit from taking supplements to increase their athletic performance. Because it is an essential part of hemoglobin, the protein that carries oxygen in the blood, iron plays a crucial part in the delivery of oxygen to the muscles. Lack of iron can affect an athlete's performance and endurance because their muscles may not be getting enough oxygen.
Increasing the body's iron reserves and enhancing oxygen transport to the muscles using iron supplements may enhance sports performance. Iron supplementation is not advised for athletes who do not have an iron deficiency, though, as too much iron can have negative effects on the body.³
Athletes who are thinking about taking iron supplements should first speak with a healthcare professional to see whether they are iron deficient and to decide the best dosage. Regular blood tests to monitor iron levels are also advised to ensure that iron levels stay within a safe range. Athletes should also concentrate on following a wholesome, balanced diet, including foods rich in iron to assist their athletic performance.
4. Cognition function
A lack of iron in your diet can negatively impact brain functioning. That's because iron is involved in getting oxygen to the brain; Neurotransmitter production also relies on iron.
Without enough iron, the body may be unable to create enough hemoglobin, which can lower the amount of oxygen getting to the brain. This might result in trouble concentrating, a short attention span, and memory issues.
Children who are iron deficient may experience delays in language and motor development as well as impaired cognitive development.⁴
Side effects of iron supplements
The following side effects of taking iron supplements have been noted:
- Nausea and vomiting
- Constipation or diarrhea
- Stomach pain or cramps
- Heartburn
- Dark or black stools
- Tooth staining
- Headaches
- Dizziness
- Muscle weakness or pain
- Difficulty breathing
Iron supplements may negatively interact with other medications. Here are some medications that have been shown to be problematic:
- Tetracycline antibiotics
- Proton pump inhibitors
- Antacids
Taking too much iron is bad for the body and can result in toxicity. The liver may be damaged if you overdose on iron.
What to look for when buying an iron supplement:
There are a number of things to consider when purchasing iron supplements to ensure you are getting a safe, effective product. Here are six things to consider before clicking on the buy now button.
1. Ingredients
Iron should be the main ingredient in an iron supplement. However, some products contain additional compounds designed to enhance their effects. These may include vitamin C and amino acids.
Some iron supplements could include allergens, including gluten, dairy, or soy. Make sure you thoroughly read the label and look for any allergens that can raise a red flag. Be on the lookout for iron supplements, especially those in powder form, that include synthetic flavorings and preservatives to improve the flavor and texture of the product. These may have a negative effect on your body.
We recommend selecting an iron supplement containing only the necessary ingredients and little to no fillers and preservatives to reduce the possibility of unpleasant reactions. Make sure you thoroughly read the label and look for any potentially problematic substances. Speak with a healthcare professional if you have any queries or worries regarding the ingredients of your iron supplement.
2. Form of iron
It's crucial to pick an iron form that the body will readily absorb and tolerate when purchasing an iron supplement. The following are a few types of iron that are frequently seen in supplements:
- Iron bisglycinate chelate: This form of iron is has shown increased tolerance and less side effects compared with other forms of iron.
- Ferrous sulfate: The form of iron supplement that is most frequently used is ferrous sulfate. Although the body absorbs it effectively, some people may experience negative digestive effects.
- Ferrous gluconate: Ferrous gluconate is another form of iron that is well-absorbed by the body. It may be better tolerated by some people than ferrous sulfate.
- Ferrous fumarate: Ferrous fumarate is a configuration of iron that is well-absorbed by the body and might be less likely to cause digestive side effects than ferrous sulfate.
- Heme iron: Heme iron is a kind of iron that is found in animal-based foods, such as red meat, poultry, and fish. It is more easily absorbed by the body than non-heme iron, found in plant-based foods.
- Carbonyl iron: Carbonyl iron is a highly purified form of iron that is well-absorbed by the body and might be less likely to cause digestive side effects than other forms of iron.
3. Dosage
Age, gender, and medical history are just a few of the variables that can affect the proper dosage of an iron supplement. In general, adults should consume the following amount of iron per day:
- Men - 8 mg
- Women of childbearing age - 18 mg
- Women over 50 - 8 mg
- Expectant mothers - 27 mg
The normal dosage range for iron supplements is 18 to 65 mg per pill or capsule. The right amount of iron supplementation for you, however, will depend on your unique needs and medical background. We recommend consulting with a healthcare professional to establish the right dosage for you.
4. Testing/Transparency
Because they are categorized as dietary supplements rather than prescription medications, iron supplements are not subject to the same stringent regulations. The quality and purity of iron supplements sold on the market can therefore vary. You can help in ensuring that you are getting a high-quality, safe, and effective product by selecting a brand from a business that conducts rigorous testing and is open about the quality of its ingredients.
Look for a product that displays a 3rd party tested sticker on the label. This indicates that the manufacturer uses an independent laboratory to carry out purity and potency testing.
5. Price
When considering the price of iron supplements, quality is a crucial aspect to take into account. Higher-quality supplements that have undergone independent testing for potency and purity may be more expensive than those that have not undergone such testing.
The cost of the iron supplement may also vary depending on how much is taken. Those with higher doses of iron are likely to be more expensive than those with lower doses.
The price of an iron supplement may also be influenced by brand reputation. Established, well-known companies may charge more for their products than smaller, less well-known brands.
Another cost consideration is the type of iron used. Some forms, such as heme iron, cost more than others, like ferrous sulfate.
6. Reviews
Customer reviews can provide valuable information about the quality and purity of the product. Customers may comment on whether the product appears to be high-quality and free of contaminants.
Reading reviews can also provide insights into the effectiveness of the product. Customers may comment on whether the product helped to alleviate their symptoms of iron deficiency or anemia, as well as mention any potential side effects.
Iron Supplement FAQs
Should I take an iron supplement daily?
Your healthcare professional may advise taking an iron supplement daily if you have been identified as having an iron deficiency or anemia or if you are experiencing iron deficiency symptoms like weakness or exhaustion. However, taking an iron supplement every day might not be essential and might even be harmful if your iron levels are high enough.
We recommend consulting your healthcare provider to establish the right dosage and frequency for you.
What type of iron supplement is best?
There is no one form of iron supplement that is best for everybody. It depends on your individual situation and your preferences. The most common types of iron found in supplements are bisglycinate chelate, ferrous sulfate, heme iron, ferrous gluconate, ferrous fumarate, and carbonyl iron.
You should consult your healthcare provider to determine which form is best for you.
Is taking an iron supplement good for you?
If you have an iron deficiency, which can lead to anemia or other medical issues, taking an iron supplement may be beneficial for you. The production of hemoglobin relies on iron. Anemia, a disorder marked by exhaustion, weakness, and shortness of breath, can result from a lack of iron, which prevents the body from producing enough hemoglobin.
People who have not been identified as being iron deficient do not need to take iron supplements. Doing so may provide the body with too much iron, which can result in toxicity.
How much iron should I be taking a day?
The National Institute of Health has provided the following RDAs for iron:
- Infants 0-6 months: 0.27 mg
- Infants 7-12 months: 11 mg
- Children 1-3 years: 7 mg
- Children 4-8 years: 10 mg
- Children 9-13 years: 8 mg
- Males 14-18 years: 11 mg
- Females 14-18 years: 15 mg
- Males 19-50 years: 8 mg
- Females 19-50 years: 18 mg
- Pregnant females: 27 mg
- Breastfeeding females: 9-10 mg
Summary
Iron is an essential mineral that has a crucial role in the production of energy. It is also crucial for optimized cognitive functioning and helps improve athletic performance. People who are iron deficient may experience fatigue, weariness, and lethargy. Taking a daily iron supplement can help reverse these effects.
The best iron supplement on the current market is Thorne Iron Bisglycinate, which provides you with 25 mg of iron bisglycinate per capsule.
Iron Bisglycinate provides an optimal way to supplement iron, which is essential for red blood cell formation. It helps fight fatigue and other symptoms of iron deficiency in athletes and others. NSF Certified for Sport...
Interested in reading more about other common nutrient deficiencies? Check out our articles on the best Vitamin D Supplements and Magnesium Supplements.
References
- Okam MM, Koch TA, Tran MH. Iron Supplementation, Response in Iron-Deficiency Anemia: Analysis of Five Trials. Am J Med. 2017 Aug;130(8):991.e1-991.e8. doi: 10.1016/j.amjmed.2017.03.045. Epub 2017 Apr 26. PMID: 28454902.
- Houston BL, Hurrie D, Graham J, Perija B, Rimmer E, Rabbani R, Bernstein CN, Turgeon AF, Fergusson DA, Houston DS, Abou-Setta AM, Zarychanski R. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open. 2018 Apr 5;8(4):e019240. doi: 10.1136/bmjopen-2017-019240. PMID: 29626044; PMCID: PMC5892776.
- Nielsen P, Nachtigall D. Iron supplementation in athletes. Current recommendations. Sports Med. 1998 Oct;26(4):207-16. doi: 10.2165/00007256-199826040-00001. PMID: 9820921.
- Jáuregui-Lobera I. Iron deficiency and cognitive functions. Neuropsychiatr Dis Treat. 2014 Nov 10;10:2087-95. doi: 10.2147/NDT.S72491. PMID: 25419131; PMCID: PMC4235202.
Steve Theunissen
Author