The 13 Best Iron Supplements of 2023, According to Dietitians

Types of iron

For those who need an iron supplement, choosing the right product can seem overwhelming because so many different types of iron supplements are available.

The most popular types are ferrous and ferric iron salts, which include ferric sulfate, ferrous gluconate, ferrous sulfate, and ferric citrate.

Because of its higher solubility, ferrous iron tends to be more bioavailable than ferric iron, which means it’s easier for your body to absorb (2).

You may also find other forms of iron, such as:

• heme iron polypeptides
• carbonyl iron
• iron amino acid chelates
• polysaccharide-iron complexes

Some forms of iron, such as ferrous sulfate, are more likely to cause GI disturbances, including constipation, than other forms, such as iron bisglycinate chelate (3, 4).

Here are the 13 best iron supplements.

A quick look at the best iron supplements

• Best multivitamin with iron: Ritual Essential for Women Multivitamin 18+ | Skip to Review
• Best vegan iron supplement: MegaFood Blood Builder | Skip to Review
• Best vegan iron supplement with vitamin C: Garden of Life Vitamin Code Raw Iron | Skip to Review
• Best vegetarian iron supplement: NOW Iron | Skip to Review
• Best iron supplement for anemia: Thorne Iron Bisglycinate | Skip to Review
• Best affordable iron supplement: Nature Made Iron 65mg Tablets | Skip to Review
• Best iron supplement with vitamin C: Pure Encapsulations OptiFerin-C | Skip to Review
• Best subscription-based iron supplements:
  • Care/of Iron | Skip to Review
  • Persona Iron with Vitamin C | Skip to Review
• Best chewable iron supplement: Klaire Labs Chewable Iron Chelate | Skip to Review
• Best iron supplement for sensitive stomachs: Pure Encapsulations Iron Liquid | Skip to Review
• Best liquid iron supplement: NOW Liquid Iron | Skip to Review
• Best prenatal with iron: Thorne Basic Prenatal | Skip to Review

How we chose

This article examines iron supplements based on the following criteria:

• Quality: The iron supplements are tested for quality and purity, ideally by a third-party organization.
• Iron type: The supplements contain easily absorbed forms of iron.
• 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.

Healthline’s picks of the best iron supplements

A comparison of the best iron supplements

Here’s a quick look at how our top picks compare:

Why is iron important?

Iron is a mineral present in:

• Hemoglobin: a protein that transports oxygen from your lungs to your tissues
• Myoglobin: another protein that carries and stores oxygen for your muscles

Iron is also essential for (2):

• brain cell development
• physical growth
• hormone synthesis
• muscle metabolism

In order to support these important processes, your body needs a steady supply of iron from your diet.

Iron exists in two forms in nature (11):

• Heme iron: a form of iron that is found in animal-derived foods and is more readily absorbed by the human body
• Non-heme iron: a form of iron that is found in plant-based and iron-fortified foods and is not as well absorbed as heme iron

You can also take iron in supplement form. Iron supplements may be necessary for those who don’t get enough iron in their diet and those who have increased iron needs.

Who should take iron supplements?

People with adequate iron stores should aim to meet their iron needs through foods rather than supplements.

However, you might need an iron supplement if you:

• are treating an existing iron deficiency
• have low iron stores
• are trying to maintain healthy iron levels

Populations that may benefit from an iron supplement include:

• infants and kids
• people who are pregnant
• people with heavy menstrual bleeding
• people with certain forms of cancer, such as colon cancer
• people with GI 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:

• they do not respond to oral iron
• 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.

How to choose an iron supplement

It’s important to consider several factors when choosing an iron supplement, including the type of iron, provided dose, and product quality and safety.

Dosing

Talk with a healthcare professional about proper dosing.

Here are the current Recommended Dietary Allowances for iron in healthy teens and adults (2):

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.

Product quality and safety

When shopping for an iron supplement, look for high quality products that have undergone third-party testing for quality and purity by credible organizations such as USP and NSF International.

It’s also important to choose products that are manufactured in facilities that adhere to the CGMPs established by the FDA.

How to take iron supplements

Iron deficiency anemia is typically treated with daily oral iron supplements for at least 3 months to replenish iron stores. For some people, healthcare professionals may recommend continuing to take iron supplements even after hemoglobin levels return to normal (1).

For those with iron deficiency, taking an iron-only supplement is a good idea because other nutrients commonly found in multivitamins, such as calcium, may inhibit iron absorption.

Additionally, it’s recommended to take iron supplements between meals and avoid pairing them with foods or beverages that may inhibit iron absorption, such as (5):

• tea
• coffee
• milk

Instead, it can be a good idea to take iron with a source of vitamin C, such as orange juice or bell peppers, because it can help enhance iron absorption (5).

Potential side effects and safety concerns

Certain iron supplements are more likely to cause side effects than others. Also, iron can be toxic if taken in very high doses.

This is why it’s important to discuss proper dosing with a healthcare professional before starting to take iron supplements.

Potential side effects of taking iron supplements include (2, 3, 4):

• constipation
• diarrhea
• nausea
• abdominal pain

To reduce the risk of side effects and toxicity, it’s best to avoid exceeding the established Tolerable Upper Intake Levels for iron supplements unless a healthcare professional recommends it. These levels are as follows (2):

• 40 mg per day for babies and kids
• 45 mg per day for teens and adults

Finally, it’s important to keep iron supplements out of reach of children because children are more susceptible to iron toxicity than adults. Children may mistake iron supplements for candy and ingest large amounts, which can be fatal (12).

Drug interactions

Iron supplements may also interact with certain medications.

For example, iron supplements may reduce the absorption of medications used to treat Parkinson’s disease and may lower the effectiveness of levothyroxine, a common drug used to treat (2):

• hypothyroidism
• goiter
• thyroid cancer

On the other hand, some medications — such as proton pump inhibitors, which are used to treat acid reflux or stomach ulcers — can reduce iron absorption because they lower the secretion of gastric acid, which plays a key role in iron uptake (2).

When to see a doctor

Having too little iron in your body can cause symptoms such as (2):

• fatigue
• weakness
• difficulty concentrating

Some people are more at risk for developing iron deficiency anemia, including:

• people with heavy periods
• pregnant people
• people with medical conditions that cause malabsorption of nutrients

If you think you may have iron deficiency, it’s important to visit a healthcare professional to undergo appropriate testing.

Do not try to treat iron deficiency on your own. Even though most people respond well to oral iron supplements, some people may need iron infusions to effectively increase their iron levels (5).

Frequently asked questions

Do iron pills really work?

Yes, for most people. Oral iron supplements are usually the first choice for treating iron deficiency anemia.

However, some people with iron deficiency anemia may need iron infusions if they don’t respond to oral iron, if they can’t properly absorb iron, or if their iron losses are too large to be treated with oral iron supplements.

What is the best form of iron supplement to take?

This depends on your specific health needs.

There are many forms of bioavailable iron on the market. The most popular ones are ferrous and ferric iron salts, which include:

• ferric sulfate
• ferrous gluconate
• ferrous sulfate
• ferric citrate

Certain types of iron, such as ferrous bisglycinate chelate, are less likely to cause GI symptoms such as constipation than other forms, like ferrous sulfate.

How can I boost my iron levels quickly?

It takes time to increase your iron levels, especially if your blood levels are low. If you have low iron, a healthcare professional can recommend a personalized treatment plan.

Generally, iron deficiency anemia is treated with daily oral iron supplements for at least 3 months in order to replenish tissue iron stores.

How much iron should I take in supplement form?

The amount of iron you may take will depend on your iron levels.

For people with iron deficiency, the typical recommendation is to take iron in divided daily doses to reach 100–200 mg of elemental iron per day.

However, studies suggest that taking smaller doses of iron once daily and taking iron every other day may help improve absorption and tolerability (5).

Ask a healthcare professional for specific dosing instructions.

Is it OK to take iron supplements every day?

Yes, it can be, for those who need it.

Most people don’t need to take iron daily, and taking too much can lead to iron toxicity.

However, people who have chronically low iron stores or inadequate dietary iron intake may need to take a daily iron supplement to maintain optimal iron levels.

If you have questions about iron supplement dosing and how often you should be taking your iron supplement, reach out to a doctor for advice.

What can I take with iron supplements to avoid constipation?

There are a few ways you can avoid or ease constipation when taking iron supplements. You can try spreading the recommended dose into a few smaller doses throughout the day and staying hydrated.

It’s also a good idea to start by taking half the recommended dose and slowly increase the amount over the course of a few days until you reach the recommended dose.

Additionally, it’s helpful to consider the type of iron before purchasing a supplement. For example, ferrous sulfate is more likely to cause constipation than other forms, such as iron bisglycinate chelate (3, 4).

If you’re still experiencing constipation, a stool softener may be helpful. Just be sure to talk with a healthcare professional before trying this.

The bottom line

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 become necessary to help you reach your daily iron needs.

Many types of iron supplements are available and contain varying doses and forms of the mineral.

Remember to consult a healthcare professional before taking any new supplement and consider the factors mentioned above to help you choose a high quality product.

Signs and symptoms of iron deficiency