Iron
Description
Iron is a vital mineral that plays a crucial role in the formation of hemoglobin, a protein in red blood cells responsible for transporting oxygen from the lungs to all parts of the body. It is also essential for myoglobin, a protein that supplies oxygen to muscles, and for various enzymes involved in energy production and DNA synthesis. Adequate iron levels are critical for maintaining energy levels, supporting immune function, and promoting cognitive health. Iron deficiency can lead to anemia, characterized by fatigue, weakness, and impaired cognitive function. However, both too little and too much iron can be detrimental to health. The body's ability to absorb iron is influenced by several factors, including the form of iron (heme vs. non-heme) and the presence of other dietary components. Heme iron, found in animal products, is more readily absorbed than non-heme iron, found in plant-based foods.
Sources
Red meatPoultryFishBeansLentilsSpinachFortified cerealsTofuNutsDried fruits
Cheapest Iron supplements
Best Iron supplements
Value Iron Supplements
Timing & Intake
AnytimePreferred: MorningEmpty stomachTake with Vitamin C
Best taken on an empty stomach to maximize absorption. If gastrointestinal upset occurs, it can be taken with a small amount of food. Avoid taking with Calcium, Zinc, or Manganese at the same time as they can interfere with absorption.
Daily Intake
RDA (Men)8 mg
RDA (Women)18 mg
RDI18 mg
Optimal Dosage
Minimum15 mg
Maximum30 mg
Safety & Toxicity
Upper Limit (UL)45 mg
Toxicity Threshold60 mg
Toxicity EffectLiver damage, gastrointestinal distress
Goals
Energy
Impact
Highest effect
Typical dose:18–45 mg
Iron is a critical component of hemoglobin in red blood cells. Without sufficient iron, the body cannot produce enough healthy red blood cells to carry oxygen effectively, leading directly to feelings of exhaustion, weakness, and shortness of breath. This is particularly crucial for women of childbearing age, vegetarians, and athletes.
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Hair Health
Impact
Highest effect
Typical dose:18–65 mg
Iron is essential for producing hemoglobin, which carries oxygen for the growth and repair of cells, including the cells that stimulate hair growth. Low ferritin (stored iron) levels are strongly correlated with increased hair shedding and correcting this deficiency is one of the most impactful steps for restoring hair density.
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Productivity Boost
Impact
Highest effect
Typical dose:18–45 mg
Iron is a critical component of hemoglobin, which carries oxygen to the brain. Even mild deficiency can impair energy levels, concentration, and overall cognitive performance. Ensuring adequate iron status is foundational for brain energy and productivity.
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Fitness
Impact
Situational effect
Typical dose:18–45 mg
Iron is a core component of hemoglobin, which carries oxygen to working muscles. Athletes, particularly female and endurance athletes, are at higher risk for deficiency, which directly impairs aerobic capacity and work output. Supplementation is vital for those with diagnosed low iron status.
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Immunity
Impact
Situational effect
Typical dose:8–45 mg
Iron is essential for the growth and differentiation of immune cells, and deficiency (anemia) is clearly linked to increased susceptibility to infection. However, pathogens also require iron to multiply, so supplementation should only be considered when a clinical deficiency is confirmed.
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Interactions
Positive Interactions
Negative Interactions
Calcium
Calcium can inhibit iron absorption when taken simultaneously, so it's best to separate their intake.
Zinc
High doses of Zinc can compete with iron for absorption pathways, potentially reducing iron uptake.
Manganese
Manganese can compete with iron for absorption, particularly when taken together in high amounts.
Green Tea
Compounds (tannins) in Green Tea can significantly reduce iron absorption.
Curcumin
Curcumin, the active compound in Turmeric, may inhibit iron absorption in some individuals or contexts.
Phosphorus
High intake of Phosphorus, particularly from phytates, can bind with iron and reduce its absorption.
Product stats
Price per product
Average$24.30
Median$20.06
Price per serving
Average$0.57
Median$0.39
Price per 10 mg
Average$0.63
Median$0.24
Price distribution
Price per serving distribution
Price per 10 mg
Reference amount: 10 mg
Forms
Paired ingredients
Ingredient forms
Ferrous Fumarate (91) 65
Ferrous fumarate is an iron salt often prescribed or included in supplements for treating and preventing iron deficiency anemia. It provides a significant amount of elemental iron per dose but is known to cause gastrointestinal side effects such as constipation, nausea, and stomach upset in some individuals.
Pros
- High elemental iron content per dose.
- Widely available and cost-effective.
- Effective at raising iron levels.
Cons
- Higher incidence of gastrointestinal side effects (constipation, nausea, stomach upset).
- Bioavailability can be inhibited by certain foods and compounds.
Per product
Avg$24.31
Med$21.54
Per serving
Avg$0.49
Med$0.29
Per 10 mg
Avg$1.52
Med$0.37
Price distribution
Iron Amino Acid Chelate (30) 85
Iron amino acid chelate refers to a group of iron supplements where iron is chemically bonded with amino acids. This chelation process enhances the stability of the iron molecule, preventing it from reacting with other dietary components that might inhibit absorption, and facilitates its transport across the intestinal wall, leading to better bioavailability and fewer side effects compared to non-chelated forms.
Pros
- Generally higher bioavailability than inorganic iron salts.
- Reduced incidence of gastrointestinal side effects.
- Less interference from dietary inhibitors of iron absorption.
- Well-tolerated by many individuals.
Cons
- Specific bioavailability can vary depending on the amino acid(s) used for chelation.
- May be more expensive than basic iron salts.
Per product
Avg$22.09
Med$20.49
Per serving
Avg$0.48
Med$0.33
Per 10 mg
Avg$0.44
Med$0.16
Price distribution
Ferrous Bisglycinate Chelate (27) 89
Ferrous bisglycinate chelate is a specific type of iron bisglycinate where the iron is in its ferrous (Fe2+) state, bound to two glycine molecules. This chelation protects the iron from degradation in the stomach and allows for absorption as an intact molecule, leading to very high bioavailability and significantly reduced gastrointestinal side effects compared to traditional iron salts.
Pros
- Excellent bioavailability and absorption rates.
- Significantly fewer gastrointestinal side effects due to the chelated form.
- Less reactive with other dietary components, improving absorption.
- Well-tolerated by individuals sensitive to other iron forms.
Cons
- Generally higher cost than non-chelated iron forms.
- Availability might vary depending on brand and region.
Per product
Avg$20.75
Med$17.28
Per serving
Avg$0.54
Med$0.57
Per 10 mg
Avg$0.51
Med$0.36
Price distribution
Iron Bisglycinate (27) 88
Iron bisglycinate is a highly bioavailable form of iron, designed for optimal absorption and minimal digestive upset. The iron molecule is chelated (bound) to two glycine amino acid molecules, forming a stable compound that is less likely to interfere with other nutrients and is easily absorbed through different pathways than traditional iron salts.
Pros
- High bioavailability and absorption rates.
- Significantly fewer gastrointestinal side effects compared to iron salts.
- Less likely to interact with other nutrients or foods.
- Gentle on the stomach.
Cons
- Can be more expensive than inorganic iron salt forms.
- May not be as widely available as cheaper forms in all regions.
Per product
Avg$35.99
Med$35.50
Per serving
Avg$0.74
Med$0.73
Per 1 mg
Avg$0.08
Med$0.07
Price distribution
Iron Bisglycinate Chelate (18) 89
Iron bisglycinate chelate is specifically engineered for optimal iron delivery. The iron atom is covalently bonded to two glycine amino acid molecules, creating a stable ring structure that protects the iron from gastric acids and common inhibitors in food. This allows the chelate to be absorbed intact through a protein pathway, leading to superior absorption and significantly fewer gastrointestinal side effects, making it a preferred choice for sensitive individuals.
Pros
- Highest bioavailability among common iron supplements.
- Exceptional gastrointestinal tolerance; rarely causes constipation or upset.
- Does not significantly interact with other nutrients or foods.
- Ideal for long-term supplementation and sensitive individuals.
Cons
- Typically more expensive than iron salts.
- Brand availability might vary.
Per product
Avg$25.44
Med$24.19
Per serving
Avg$0.57
Med$0.46
Per 10 mg
Avg$0.73
Med$0.45
Price distribution
Iron Glycinate (17) 87
Iron glycinate is a chelated iron supplement where iron is bound to the amino acid glycine. Similar to iron bisglycinate, this chelation helps protect the iron from gastric acids and dietary inhibitors, allowing for superior absorption in the intestines. It is well-known for being gentle on the stomach and causing significantly fewer gastrointestinal side effects compared to traditional iron salts.
Pros
- High bioavailability and efficient absorption.
- Significantly reduced gastrointestinal side effects (e.g., constipation, nausea).
- Excellent digestive tolerance, suitable for sensitive individuals.
- Less affected by food or other nutrient interactions.
Cons
- Generally more expensive than non-chelated iron forms.
- While similar to bisglycinate, the specific ratio of iron to glycine might vary between products.
Per product
Avg$43.00
Med$37.00
Per serving
Avg$0.93
Med$0.92
Per 1 mg
Avg$0.17
Med$0.19
Price distribution
Iron Aminoate Complex (14) 80
Iron aminoate complex refers to a form of iron supplement where iron is chelated or complexed with various amino acids. This binding improves the stability of the iron molecule, preventing it from reacting prematurely in the digestive tract and facilitating its absorption. The goal is to provide a more bioavailable form of iron that is also gentler on the stomach compared to simple iron salts.
Pros
- Improved absorption compared to unchelated iron salts.
- Reduced likelihood of gastrointestinal side effects.
- Good tolerability for many individuals.
- The amino acid complex can aid in nutrient delivery.
Cons
- Specific bioavailability can vary depending on the amino acids used in the complex.
- Generally more expensive than inorganic iron forms.
- Less research on specific complexes compared to bisglycinate.
Per product
Avg$32.97
Med$29.14
Per serving
Avg$0.37
Med$0.35
Per 1 mg
Avg$0.07
Med$0.06
Price distribution
Iron Gluconate (13) 70
Iron gluconate is an iron salt where iron is bound to gluconic acid. It's often used in supplement form as ferrous gluconate and typically contains less elemental iron per dose compared to ferrous fumarate or sulfate. While generally considered to be somewhat better tolerated than ferrous sulfate, it can still cause gastrointestinal side effects like nausea and constipation, though often to a lesser degree.
Pros
- Generally better tolerated than ferrous sulfate for some individuals.
- Readily available and relatively inexpensive.
- Effective at raising iron levels.
Cons
- Lower elemental iron content, requiring higher doses.
- Can still cause gastrointestinal side effects (e.g., nausea, constipation).
- Absorption can be inhibited by food and other compounds.
Per product
Avg$23.02
Med$22.06
Per serving
Avg$0.61
Med$0.52
Per 1 mg
Avg$0.10
Med$0.07
Price distribution
Ferrous Gluconate (12) 72
Ferrous gluconate is an iron salt where iron is in its ferrous (Fe2+) state, bound to gluconate. It is a widely available and cost-effective option for iron supplementation. While generally better tolerated than ferrous sulfate regarding gastrointestinal side effects like stomach upset, it can still cause issues such as constipation and nausea in some individuals. It delivers a lower percentage of elemental iron by weight compared to some other forms.
Pros
- Often better tolerated than ferrous sulfate.
- Commonly available and affordable.
- Effective at increasing iron levels with consistent use.
Cons
- Lower elemental iron content per dose (approx. 12%).
- Still carries a risk of gastrointestinal side effects (e.g., nausea, constipation).
- Absorption can be inhibited by certain foods and beverages.
Per product
Avg$20.13
Med$15.92
Per serving
Avg$0.51
Med$0.41
Per 1 mg
Avg$0.09
Med$0.08
Price distribution
Iron Glycinate Chelate (11) 87
Iron glycinate is a chelated iron supplement where iron is bound to the amino acid glycine. Similar to iron bisglycinate, this chelation helps protect the iron from gastric acids and dietary inhibitors, allowing for superior absorption in the intestines. It is well-known for being gentle on the stomach and causing significantly fewer gastrointestinal side effects compared to traditional iron salts.
Pros
- High bioavailability and efficient absorption.
- Significantly reduced gastrointestinal side effects (e.g., constipation, nausea).
- Excellent digestive tolerance, suitable for sensitive individuals.
- Less affected by food or other nutrient interactions.
Cons
- Generally more expensive than non-chelated iron forms.
- While similar to bisglycinate, the specific ratio of iron to glycine might vary between products.
Per product
Avg$18.07
Med$11.48
Per serving
Avg$0.29
Med$0.23
Per 10 mg
Avg$0.09
Med$0.09
Price distribution