The Fast Facts
- Finding the best iron supplement for your needs can feel overwhelming.
- Jillian Kubula, a registered dietitian, walks us through the best supplements to choose from.
- Thorne Iron Bisglycinate Capsules are our best overall for adults, but give Mary Ruth’s Toddler Drops a go if your kid needs a little extra supplementation.
Most people can get all the iron they need by eating a nutrient-dense, well-rounded diet. But if you have inadequate iron intake, increased need, or impaired absorption, you may be at risk of low iron levels and iron deficiency anemia.
If a healthcare professional recommends supplemental iron, you might consider the following options vetted by Healthline’s medical and nutrition experts.
Alongside our vigorous vetting process, these traits were some we considered when looking for iron supplements:
- Quality: The iron supplements are tested for quality and purity, ideally by a third-party organization.
- Iron type: The supplements contain forms of iron that are easily absorbed.
- Other nutrients: The supplements are free of nutrients that impair iron absorption and may contain nutrients that enhance absorption.
- Dose: The supplements contain an effective dose of iron.
- Price: We included products to suit a variety of budgets.
- Forms: We included iron supplements in several forms, including liquids and chewables, to suit different preferences and tolerances.
Our Medical Standards and Insights team has carefully researched and vetted over 11,000 products and services. We fact-check health claims, evaluate ingredients, and look into each brand’s reputation before sharing products and services on Healthline.
To choose the brands on this page, we considered all the vitamin brands that passed our vetting process. Then, we personally tested some of them to narrow down our list even further.
Iron, that
- Hemoglobin: This protein transports oxygen from your lungs to your tissues.
- Myoglobin: This is another protein that carries and stores oxygen for your muscles.
Your body needs a steady supply of dietary iron to support these important processes and proteins.
In nature, iron exists in
Types of iron supplements
Supplemental iron comes in different forms, each with its own
| Form | Bioavailability | Affordability | Side effects |
|---|---|---|---|
| Iron bisglycinate chelate | a bit more expensive than other forms of iron | minimal gastrointestinal side effects compared with ferrous sulfate | |
| Ferrous sulfate | well absorbed | inexpensive | in high doses, may cause gastrointestinal side effects like constipation |
| Ferric sulfate | inexpensive | in high doses, may cause gastrointestinal side effects like constipation | |
| Ferrous fumarate | well absorbed | inexpensive | in high doses, may cause gastrointestinal side effects like constipation |
Medical Perspective“The one mistake people make when they start taking an iron supplement is not drinking plenty of water to reduce constipation.”
— Jerlyn Jones, MS MPA RDN LD CLT
Learn more about why too much iron can be harmful.
Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Taking
- infants and kids
- pregnant people
- people with heavy menstrual bleeding
- people with certain forms of cancer, such as colon cancer
- people with gastrointestinal disorders, such as celiac disease and Crohn’s disease
- people with heart failure
- people who frequently donate blood
- athletes
Some people with iron deficiency anemia may need iron infusions if:
- oral iron supplementation does not work
- their bodies can’t properly absorb iron
- their iron losses are too great to be treated with oral supplements
Overall, it’s wise to talk with a healthcare professional to find out whether an iron supplement is right for you.
Warning about iron and children
Health experts do not recommend giving an iron supplement to your child unless a healthcare professional directs you to do so. Children are
How to take iron supplements
- daily oral iron supplements for at least
3 months to replenish iron stores - some people are advised to continue iron supplements even after their hemoglobin levels restore
- long term, it’s best to take an iron-only supplement because other nutrients found in multivitamins, such as calcium, may inhibit iron absorption
- take iron between meals
- take iron with a source of vitamin C, such as orange juice or bell pepper to enhance iron absorption
What not to do when taking iron supplements
- avoid pairing iron with foods or drinks that may inhibit iron absorption, such as:
- coffee
- milk
- tea
Certain iron supplements are more likely to cause side effects than others.
Potential side effects of taking iron supplements
- constipation
- diarrhea
- nausea
- abdominal pain
Iron can be toxic at very high doses. To reduce the risk of side effects and toxicity, avoid exceeding the established
These levels are as follows:
- 40 mg per day for babies and kids
- 45 mg per day for teens and adults
Drug interactions
Iron supplements
Iron supplements may lower the effectiveness of levothyroxine, a common drug used to treat:
- hypothyroidism, also called an underactive thyroid
- goiter
- thyroid cancer
On the other hand, some medications — such as proton pump inhibitors, which treat acid reflux or stomach ulcers — can
When to contact a doctor
Having too little iron in your body can cause symptoms
- fatigue
- weakness
- difficulty concentrating
- shortness of breath
Some people are more at risk of developing iron deficiency anemia, including:
- people with heavy periods
- pregnant people
- people with health conditions that cause nutrient malabsorption
If you think you may have an iron deficiency, visit a healthcare professional. They can check your iron levels with a blood test.
It’s important to consider several factors when choosing an iron supplement, including the type of iron, the provided dose, and product quality and safety.
Dosing
Here are the current
| 14 to 18 years | 19 to 50 years | 51+ years |
|---|---|---|
| 11 mg for males | 8 mg for males | 8 mg for males |
| 15 mg for females | 18 mg for females | 8 mg for females |
| 27 mg while pregnant | 27 mg while pregnant | — |
| 10 mg while nursing | 9 mg while nursing | — |
For kids and babies, the Recommended Dietary Allowances are:
| Birth to 6 months | 7 to 12 months | 1 to 3 years | 4 to 8 years | 9 to 13 years |
|---|---|---|---|---|
| 0.27 mg for males and females | 11 mg for males and females | 7 mg for males and females | 10 mg for males and females | 8 mg for males and females |
Keep in mind that if you’re low on iron, you’ll need more iron than most other people need each day.
If you have low iron stores, have a deficiency, or need extra iron for any reason, a healthcare professional can recommend a dosage that fits your needs.
Useful supplement shopping guides
Many forms of supplemental iron are effective for increasing iron levels.
Ferrous forms of iron tend to be more bioavailable than ferric iron, meaning your body more easily absorbs them.
However, some forms of iron, including ferrous sulfate, are more likely to cause gastrointestinal side effects, such as constipation, than others, such as iron bisglycinate chelate.
So, iron bisglycinate chelate is a good overall option for raising iron levels, and it’s also gentle on the stomach.
Meanwhile, iron supplements are available in several forms, including liquids, capsules, and chewable products. Liquid and chewable iron supplements are a good choice if you cannot tolerate pills or capsules.
Some people, such as those with health conditions that cause nutrient malabsorption, may require iron infusions. These are administered and monitored by a healthcare team.
If you have iron deficiency anemia, ferrous forms of iron, such as ferrous sulfate, tend to be more bioavailable than ferric iron.
Iron bisglycinate chelate is also effective for treating iron deficiency anemia. Plus, it’s gentle on the stomach. It’s often preferred over ferrous and ferric salts because it’s less likely to cause gastrointestinal side effects, such as constipation.
The amount of iron you should take depends on your iron levels.
For people with iron deficiency, the typical recommendation is to take divided daily doses to reach 100 mg to 200 mg of elemental iron per day.
However, research suggests that taking smaller doses of iron once daily or every other day may improve absorption and tolerability compared with large daily doses.
Many forms of iron are gentle on the stomach and less likely to cause gastrointestinal side effects.
If you need an iron supplement but are concerned about potential side effects like constipation, it’s best to choose a supplement that contains iron in the form of iron bisglycinate chelate over supplements that contain ferric or ferrous salts, such as ferrous sulfate.
Iron is best absorbed on an empty stomach, so it’s recommended to take it first thing in the morning, except with meals or beverages like coffee or milk.
However, some research shows that taking iron supplements with a vitamin C-rich beverage, such as orange juice, can significantly increase iron absorption.
While it’s best to take iron on an empty stomach, if iron supplements make you feel queasy, it’s OK to take them with a small meal or snack.
Iron is an important mineral that’s necessary for oxygen transport and the formation of healthy red blood cells.
While it’s always best to fulfill your iron needs through a diet high in iron-rich whole foods, supplements may sometimes be necessary to help you reach your daily iron needs.
Many types of iron supplements are available, with varying doses and forms of the mineral.
Consult a healthcare professional before taking any new supplement, and consider the factors mentioned above to help you choose a high quality product.