The 13 Best Iron Supplements of 2023, According to Dietitians

Why is iron important?

Iron is a mineral present in hemoglobin, a protein that transports oxygen from your lungs to your tissues, and myoglobin, another protein that carries and stores oxygen for your muscles.

Iron is also essential for brain cell development, physical growth, and hormone synthesis, and it supports muscle metabolism (2).

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 (3):

• 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.

A quick look at the best iron supplements

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

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

Best iron supplement for anemia

Thorne Iron Bisglycinate

• Price: $$
• Type: Ferrochel ferrous bisglycinate chelate
• Dosage: 1 capsule per day
• Certifications: NSF Certified for Sport

While there are many products to choose from, Thorne Iron Bisglycinate is one of the best for combating anemia, as it’s made by one of the most reputable supplement brands and contains only iron.

What’s more, each capsule packs 139% of the Daily Value (DV) for iron in the form of ferrous bisglycinate chelate — a form of iron that’s easy for your body to absorb and less likely to cause GI side effects than other forms of iron, such as ferrous sulfate (4, 5).

The product is also NSF Certified for Sport, meaning it’s free of substances that have been banned by most sports organizations and is therefore safe for athletes.

Additionally, Thorne’s facilities are verified by multiple international third-party organizations, including Australia’s Therapeutic Goods Administration, a regulatory agency run by the Australian Government Department of Health.

Best affordable iron supplement

Nature Made Iron 65mg Tablets

• Price: $
• Type: ferrous sulfate
• Dosage: 1 tablet per day
• Certifications: USP-verified

Nature Made boasts 65 mg of iron per capsule — that’s 361% of the DV for iron, or the equivalent of 325 mg of ferrous sulfate.

Ferrous sulfate is a common form of supplemental iron with high solubility, meaning that it releases iron ions faster and is therefore easier to absorb (4).

However, this form of iron is more likely than other forms to cause GI side effects such as constipation (5).

The product is verified by United States Pharmacopeia (USP), a third-party organization that tests quality, including a product’s purity, potency, and performance.

Best iron supplement with vitamin C

Pure Encapsulations OptiFerin-C

• Price: $$
• Type: iron bisglycinate
• Dosage: 1 capsule per day
• Certifications: certified gluten-free

Pure Encapsulations OptiFerin-C contains 28 mg of iron bisglycinate plus 100 mg of vitamin C.

Vitamin C is often added to iron supplements because it may help improve absorption (6).

The supplement is kosher, vegan-friendly, and free of gluten, soy, and dairy. It’s also produced in a CGMP-certified facility.

Pure Encapsulations products exceed the quality and purity standards set by USP (7).

According to the company’s website, Pure Encapsulations products are tested by third-party laboratories, including Skilliker, Eurofins, Intertek, and Advanced Laboratories.

Best vegan iron supplement with vitamin C

Garden of Life Vitamin Code Raw Iron

• Price: $$$
• Type: brown rice chelate
• Dosage: 1 capsule per day
• Certifications: certified vegan, certified gluten-free, non-GMO

Garden of Life Vitamin Code Raw Iron provides 22 mg of whole food iron and 25 mg of vitamin C.

The term “whole food iron” means that the iron comes from raw-food-created nutrients.

It also indicates that the supplement is produced without high heat, synthetic binders or fillers, or artificial flavors, sweeteners, colors, or additives.

Additionally, the product contains an organic fruit and vegetable blend, as well as a probiotic and enzyme blend, to support digestion.

All Garden of Life products are manufactured in an FDA-certified facility. This supplement is also certified vegan, non-GMO, kosher, raw, and gluten-free.

Best subscription-based iron supplements

Care/of Iron

• Price: $
• Type: ferrous bisglycinate chelate
• Dosage: 1 capsule per day
• Certifications: non-GMO

Care/of is a subscription vitamin service that allows you to take a quiz to personalize the vitamins and supplements you receive.

One of the supplements the brand offers is an iron supplement.

The supplement contains 18 mg of iron as ferrous bisglycinate chelate, which is less likely to cause GI symptoms such as constipation than other iron forms like ferrous sulfate (4, 5).

The supplement is also vegan, gluten-free, non-GMO, and formulated with vitamin C for easier absorption (6).

Persona Iron with Vitamin C

• Price: $$
• Type: iron Ferronyl
• Dosage: 1 capsule per day
• Certifications: non-GMO

Persona is another personalized subscription service that asks users to take a quiz and sends out vitamins and supplements that cater to their individual needs.

Persona offers an iron supplement that’s formulated to be absorbed easily and gentle on the stomach.

It contains 18 mg of iron as Ferronyl and includes vitamin C for absorption.

While the vitamin is free of gluten and major allergens, it’s produced in a facility where cross contamination may occur. Therefore, it’s not ideal for those with severe food allergies or sensitivities.

Best multivitamin with iron

Ritual Essential Multivitamin for Women 18+

• Price: $$$
• Type: iron bisglycinate
• Dosage: 2 capsules per day
• Certifications: USP-verified

Ritual Essential Multivitamin for Women 18+ is designed for people looking to help fill gaps in their diets.

Specifically, the mint-scented capsules contain iron bisglycinate, which may be easier to absorb and cause less GI distress than other types of iron (4, 5).

The supplement also includes several nutrients that you may have difficulty getting enough of from food alone, including vitamin D, DHA, and folate.

Unlike many other multivitamins, it doesn’t contain calcium, which could interfere with iron absorption (8).

Just keep in mind that while the multivitamin is vegan-friendly, it lacks several nutrients that people following a vegan diet might not get enough of, including iodine and zinc (9).

It’s also low in magnesium and doesn’t contain vitamin C or many B vitamins other than folate and B12.

Best vegetarian iron supplement

NOW Iron 18 mg

• Price: $
• Type: Ferrochel ferrous bisglycinate
• Dosage: 1 capsule per day
• Certifications: non-GMO

NOW is known for offering high quality products at affordable prices.

This supplement provides 18 mg of iron per capsule in the form of iron bisglycinate chelate, and each bottle packs 120 capsules.

Furthermore, the product is manufactured in facilities that are certified by Underwriters Laboratories (UL), a third-party testing organization that ensures products are produced according to rigorous safety standards.

It’s also certified kosher, halal, and non-GMO.

While it’s made without gluten or major allergens, NOW supplements are produced in facilities where cross contamination may occur.

Best vegan iron supplement

MegaFood Blood Builder

• Price: $$$
• Type: iron bisglycinate
• Dosage: 1 tablet per day
• Certifications: certified gluten-free, certified vegan, glyphosate residue-free

MegaFood Blood Builder provides 26 mg of iron in the form of iron bisglycinate, as well as 15 mg of vitamin C for improved absorption.

What’s more, the product offers folate and B12, both of which are important for maintaining healthy blood cells.

All MegaFood supplements are verified by six third-party testing organizations. The company’s certifications include B Corporation, NSF gluten-free, non-GMO, kosher, vegan, and glyphosate residue-free.

However, keep in mind that the products aren’t third-party tested for accuracy or potency.

Best chewable iron supplement

Klaire Labs Chewable Iron Chelate

• Price: $$
• Type: Ferrochel ferric trisglycinate chelate
• Dosage: 1 chewable tablet per day
• Certifications: non-GMO

Much like liquid supplements, chewable supplements are a convenient and tasty way to take your vitamins and minerals.

Klaire Labs Chewable Iron Chelate provides 30 mg of elemental iron as Ferrochel ferric trisglycinate chelate, which is a highly absorbable form of iron.

The tablets have a natural cherry flavor and contain less added sugar than many other chewable supplements on the market.

Klaire Labs supplements are manufactured in CGMP-certified facilities.

Best iron supplement for sensitive stomachs

Pure Encapsulations Iron Liquid

• Price: $$$
• Type: ferric pyrophosphate
• Dosage: 1 teaspoon (5 mL) per day
• Certifications: certified gluten-free

Pure Encapsulations Iron Liquid provides 15 mg of iron per 1-teaspoon (5-mL) serving in the form of SunActive Fe, a form of iron with high bioavailability that’s well tolerated and doesn’t cause gastrointestinal issues (10).

This makes Pure Encapsulations Iron Liquid a good alternative for people who experience gastrointestinal side effects such as constipation when taking iron salts (10).

It also contains a blend of cranberry and wild blueberry extract, which is meant to provide antioxidant support.

This product exceeds standards set by USP and is tested by third-party laboratories for quality and purity. It’s also gluten-free and vegetarian-friendly.

Pure Encapsulations Iron Liquid is sweetened with apple juice concentrate and flavored with natural pomegranate flavor.

Best liquid iron supplements

NOW Iron Liquid

• Price: $$
• Type: ferric glycinate
• Dosage: 2 teaspoons (10 mL) per day
• Certifications: certified kosher

For those who don’t like to swallow capsules or take chewable supplements, liquid iron products are the way to go.

NOW Liquid Iron provides 18 mg of iron as ferric glycinate, a gentle form of iron that’s less likely to cause constipation than other types of iron, such as ferrous sulfate (4, 5).

Unlike many other liquid iron supplements, NOW Liquid Iron contains zero added sugars. Instead, it’s sweetened with the sugar alcohol xylitol, so it’s a good choice for those who are managing their blood sugar levels, such as people with diabetes.

Just keep in mind that consuming high amounts of xylitol can cause gastrointestinal side effects, including gas and bloating. Therefore, this product may not be ideal if you regularly consume xylitol-containing foods and beverages (11).

NOW Liquid iron is manufactured in UL-certified facilities and is certified kosher, halal, and non-GMO.

Best prenatal with iron

Thorne Basic Prenatal

• Price: $$$
• Type: Ferrochel ferrous bisglycinate chelate
• Dosage: 3 capsules per day
• Certifications: gluten-free

Although Thorne Basic Prenatal is designed for pregnant and breastfeeding women, it can also be used as a multivitamin for those who are looking for a multivitamin that contains more than 100% of their daily iron needs.

This prenatal supplement provides 167% of the DV for iron in the highly bioavailable form of Ferrochel ferrous bisglycinate chelate. It also contains vitamin C; zinc; folate; iodine; selenium; vitamins B6, B12, and D; and many other nutrients important for women’s health.

Thorne Basic Prenatal is a well-rounded multivitamin that’s appropriate for women of childbearing age who need extra iron in their diets.

A comparison of the best iron supplements

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

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’re treating an existing iron deficiency or low iron stores or if you’re 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, like celiac or Crohn’s disease
• people with heart failure
• people who frequently donate blood
• athletes

Never give an iron supplement to your child unless a healthcare professional recommends it. Children are more susceptible to developing iron toxicity than adults (12).

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 supplements.

Overall, make sure 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.

Type 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.

Due to 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 (HIP), carbonyl iron, iron amino acid chelates, and polysaccharide-iron complexes (PIC).

Some forms of iron, like ferrous sulfate, are more likely to cause GI disturbances such as constipation than other forms, such as iron bisglycinate chelate (4, 5).

Dosing

Talk with a healthcare professional about proper dosing.

Here are the current Recommended Dietary Allowances (RDAs) 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 works best for 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 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, you should take iron supplements between meals and should not pair them with tea, coffee, milk, or other foods or beverages that may inhibit iron absorption (8).

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 (8).

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, 4, 5):

• 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 hypothyroidism, goiter, and thyroid cancer (2).

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 fatigue, weakness, and difficulty concentrating (2).

Some people are more at risk for developing iron deficiency anemia, including women with heavy periods, pregnant people, and folks 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 raise their body’s iron levels (8).

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, and ferric citrate.

Certain types of iron, like ferrous bis-glycinate 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 vary, depending on your iron levels.

For people with iron deficiency, it’s typically recommended 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 (8).

Ask a healthcare professional for specific dosing instructions. Never take high dose iron pills unless recommended and monitored by a healthcare professional.

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 with chronically low iron stores and those who have 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 your 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, be sure to consider the form of iron before purchasing a supplement. Some forms of iron, like ferrous sulfate, are more likely to cause constipation than other forms, such as iron bis-glycinate chelate (4, 5).

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