Iron
Iron Bisglycinate
Iron bisglycinate is a chelated form of iron where the mineral is bound to two glycine molecules, offering superior bioavailability compared to traditional iron salts like ferrous sulfate. It is primarily used to treat or prevent iron deficiency anemia, a condition characterized by insufficient iron stores to support healthy red blood cell production. This form is especially favored for individuals who experience gastrointestinal intolerance with conventional iron supplements.
Mechanism of Action
Iron bisglycinate is absorbed via a peptide transporter pathway (PepT1) in addition to the classical divalent metal transporter-1 (DMT1) route used by inorganic iron salts, allowing uptake even in less acidic intestinal environments. Once absorbed, iron is incorporated into hemoglobin within red blood cells, enabling oxygen transport, and is also used in myoglobin, cytochromes, and various iron-dependent enzymes critical for energy metabolism and DNA synthesis. The chelated glycine structure protects the iron from forming insoluble complexes with dietary inhibitors like phytates and tannins, substantially increasing net absorption.
Evidence by Health Goal(18 goals)
Dosing Protocols
On empty stomach or with a small amount of food if GI discomfort occurs; take with vitamin C to enhance absorption
Therapeutic dosing for iron deficiency anemia typically ranges from 25-100mg elemental iron daily depending on severity; maintenance or prophylactic dosing is often 18-36mg. Every-other-day dosing has emerging evidence for improved absorption and fewer side effects. Recheck ferritin and hemoglobin after 8-12 weeks.
Safety & Side Effects
Iron bisglycinate has a favorable safety profile with significantly fewer GI side effects than ferrous sulfate, making it well tolerated at therapeutic doses; however, iron supplementation should never be initiated without confirming deficiency via bloodwork, as excess iron is toxic and individuals with hemochromatosis, hemolytic anemias, or hemosiderosis face serious risk of iron overload. Keep iron supplements out of reach of children, as acute iron poisoning is a leading cause of fatal pediatric poisoning.
Possible Side Effects
- !Constipation or darkening of stools (less common than with ferrous sulfate)
- !Nausea and mild gastrointestinal discomfort, particularly at higher doses
- !Abdominal cramping or bloating
- !Metallic taste in the mouth
- !Diarrhea in sensitive individuals
- !Iron overload symptoms (fatigue, joint pain, organ damage) with chronic excessive dosing
- !Teeth staining if liquid formulations are not used with a straw
Interactions
- -Antacids and proton pump inhibitors (e.g., omeprazole) reduce iron absorption by raising gastric pH — separate by at least 2 hours
- -Calcium supplements and dairy products inhibit iron absorption — avoid co-administration
- -Tetracycline and fluoroquinolone antibiotics form insoluble complexes with iron, reducing efficacy of both — separate by at least 2 hours
- -Levothyroxine absorption is significantly reduced by concurrent iron — take thyroid medication at least 4 hours apart
- -Vitamin C (ascorbic acid) enhances iron absorption and can increase elemental iron uptake by up to 30% when co-administered
Cost & Where to Buy
Iron bisglycinate is widely available OTC; cost varies by brand, dose, and whether it is a standalone product or part of a multivitamin. Premium brands (Thorne, Pure Encapsulations) trend higher; generic and store brands offer cost-effective alternatives with similar efficacy.
Search on Amazon